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Sponsored by: Northwestern Polytechnical University  Chinese Society Aeronautics and Astronautics
Address: Aviation Building,Youyi Campus, Northwestern Polytechnical University
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    [Abstract] (248) [HTML] (225) [PDF 472.29 K] (522)
    Abstract:
    As a general quality characteristic with comprehensive feature, the Aircraft Structure Operational Integrity (ASOI) is the basis for aircraft structure to exert its operational applicability and effectiveness. The ASOI includes 6 characteristics,such as durability, supportability, safety, structural capability, survivability and recoverability. And even the same structural design techniques may have different effects on the 6 characteristics. In order to improve the ASOI, the development requirements of aircraft structural strength are discussed from the perspective of 6 characteristics of ASOI, based on the analysis of ASOI meaning and aircraft combat characteristics. In addition, the influence of typical structural design techniques on ASOI is also analyzed.
    2023,14(5):8-18. DOI: 10.16615/j.cnki.1674-8190.2023.05.02
    [Abstract] (173) [HTML] (607) [PDF 1.93 M] (891)
    Abstract:
    Establishing testing pyramids with building blocks approach is a widely accepted process for the structural strength verification of large aircraft. This article briefly summaried the historial developments and trendencies of building block approach and testing pyramids. In the verification processes of aircraft structural strengthes, the building block approach is applied to construct various forms of testing pyramids with different verification objects. In order to verify various “New” related technologies, the objects can be materials, design configurations, design methods and calculation tools, manufacturing, assembly and maintenance processes, as well as the full scale componemts and whole aircraft. On this basis, the statistical results for the testing pyramids established in various US military aircraft developments are also presented with the numbers of ranges, the proportions of the amounts and costs. The presented results include four aspects: the level of experiment, the object, the aim and the type of experiments. These results can explain the importance and economy of the applications of the testing pyramids in the verifications for aircraft structural designs. The works in the basic levels of testing pyramids, not only provide solid design allowable values for related design methods / tools in multiple levels, but also provide reliable means of compliances to the developments of full scale components and whole aircraft. Finally, the application developments, trendencies and limitations of the virtual tests for aircraft developments are also introduced.
    2023,14(5):19-28. DOI: 10.16615/j.cnki.1674-8190.2023.05.03
    [Abstract] (210) [HTML] (192) [PDF 4.49 M] (638)
    Abstract:
    AES(Airborne electronic suits)are carried in certain structures of military aircrafts, which contribute the relevant EMP/EMH(Electromagnetic Protection/Electromagnetic Hardening) characteristics for the AES. For military aircrafts, the EMP/EMH characteristics of aircraft structures have a great impact on the AES, so the EMP/EMH characteristics of aircraft structures is one of the important parts of its operational integrity. The EMP/EMH concept is attributed from perspectives of both EMC(Electro-Magnetic Compatibility) and the EW(Electromagnetic Warfare), which is followed the concept of electromagnetic hardening or reinforcement. The EMP/EMH of aircraft structures is combined engineering technology and operational tasks. Several typical EMP/EMH measures of aircraft structures are proposed based on the analysis of typical electromagnetic threats, the EMP/EMH characteristics of aircraft structure and the electromagnetic damage mechanism ware analyzed from aircraft structure, which was in order to improve the operational integrity of AES.
    2023,14(5):29-34,60. DOI: 10.16615/j.cnki.1674-8190.2023.05.04
    [Abstract] (274) [HTML] (218) [PDF 1.35 M] (609)
    Abstract:
    Aero-engine is a device that provides power for aviation equipment. Maintenance is an important stage in the whole system and whole cycle of aero-engine. The development history of aero engine maintenance is introduced briefly. The aero-engine repair technology development is presented based on fault inspection, deposit washing, assembling and remanufacturing technology development is presented based on development history, key technologies and development process. Finally, the development prospect of aero-engine maintenance and remanufacturing is forecasted.
    2023,14(5):35-44. DOI: 10.16615/j.cnki.1674-8190.2023.05.05
    [Abstract] (233) [HTML] (106) [PDF 1.60 M] (400)
    Abstract:
    Accurate prediction of fatigue crack growth serves as the cornerstone for aircraft component lifespan monitoring and residual life estimation. In this paper, a prediction method of structural crack propagation based on dynamic Bayesian network is proposed, which combines the prior knowledge and the posterior knowledge of fatigue crack propagation to accurately infer the crack length. The influence of different particle numbers on the inference accuracy of the dynamic Bayesian network was studied. Through the study of crack propagation of the single hole plate and the lug under random load spectrum, it is shown that the dynamic Bayesian network method can accurately predict the crack growth of structures, and the prediction accuracy is more than 50% higher than that of the traditional method.
    2023,14(5):44-53. DOI: 10.16615/j.cnki.1674-8190.2023.05.06
    [Abstract] (387) [HTML] (233) [PDF 1.33 M] (736)
    Abstract:
    With the wide application of fibre-reinforced composites in aerospace, the fatigue problem of composites is becoming more and more prominent. In order to achieve efficient and accurate fatigue damage analysis, a data-mechanism driven method for the progressive analysis of fatigue damage in composites is proposed. The method utilizes a single-hidden-layer neural network as its fatigue constitutive law for simulations of fatigue delamination under cyclic loading. In order to achieve neural network training with a small quantity of samples, this paper uses a Paris-law-informed regulations to achieve data-mechanism fusion for neural network model training. The ability to analyze fatigue delamination is validated in in the full range of mode-I and mode-II as well as mixed modes of different mode ratios using double cantilever beam (DCB) and 4-point end flexure (4ENF), the paper further verifies the applicability of the cohesive model in the case of complex fatigue delamination front using an reinforced double cantilever beam (R-DCB) model. The numerical results of this paper show that the data-mechanism driven fatigue damage progressive analysis method for composites could rapidly and effectively simulate the composite delamination propagation with high fidelity, providing a new idea and method for composite structure design and safety assurance.
    2023,14(5):54-60. DOI: 10.16615/j.cnki.1674-8190.2023.05.07
    [Abstract] (285) [HTML] (213) [PDF 4.87 M] (622)
    Abstract:
    Fatigue life scatter factor of aircraft damaged structures is an important parameter to analyze the fatigue life dispersion degree of damaged structures. In this paper, the fatigue test of prefabricated damage test pieces is carried out for aluminum alloy materials commonly used in aircraft. The distribution type of residual fatigue life of damaged structures is determined by correlation coefficient comparison method. The relationship between damage and fatigue life and the dispersion of residual fatigue life of damaged structures were analyzed through fracture observation and statistical data processing. The results show that the residual fatigue life of damaged structures is consistent with Weibull distribution. The fatigue life of the structure with preset damage decreases obviously compared with that without preset damage, and the residual fatigue life of the structure decreases gradually with the increase of preset damage size. With the increase of the preset damage size, the residual fatigue life dispersion increases, and the fatigue life dispersion of different structures with initial crack damage is different. The work in this paper provides a reference for establishing fatigue life scatter factor models of aluminum alloy structures with different damage sizes.
    2023,14(5):61-69. DOI: 10.16615/j.cnki.1674-8190.2023.05.08
    [Abstract] (185) [HTML] (120) [PDF 2.06 M] (283)
    Abstract:
    It is of great practical significance for real-time health monitoring to reconstruct other position responses by using limited measuring point information of wing box structure in complex navigation with harsh bearing conditions In this paper, the nonlinear relationship between the responses is obtained by training the back propagation neural network, and the response reconstruction method based on neural network is established and verified by numerical simulation by finite element analysis. Finally, the method is applied to the response reconstruction, damage location and judgment analysis of typical load-bearing structures of wing boxes under measured random excitation environment The results show that the RMS relative error of the predicted response power spectral density reconstructed by this method is less than 1.90 dB and the main frequency error is less than 10%; The damage or fault of the key measuring point E of the wing box occurred 3s after the intercepted fragment data, and its fault characteristic frequency was about 240Hz, which indicated the feasibility of applying this method to response reconstruction prediction and health monitoring analysis.
    2023,14(5):70-77. DOI: 10.16615/j.cnki.1674-8190.2023.05.09
    [Abstract] (304) [HTML] (151) [PDF 798.66 K] (370)
    Abstract:
    Aiming at various genetic algorithms commonly used in composite layer optimization, it is difficult to comprehensively consider complex engineering constraints such as surface 45 degrees, layering ratio, and continuous layer number limit, this paper proposes an isogenic sequence double random genetic algorithm for composite laminates, which can consider the layering in the optimization. Complex engineering constraints such as ratio, continuous layup limit, adjacent layup angle, surface laying ±45°, etc., the introduction of double random algorithms in the exchange and mutation operators ensures the strict equality of gene sequences in the optimization iteration, and based on the SABRE software The optimization method is realized, the results of calculation and application show that the proposed method can fit complex engineering constraints such as balance, symmetry, surface 45 degrees, continuous ply number limit, ply ratio, etc., and has high reliability and engineering applicability.
    2023,14(5):78-84. DOI: 10.16615/j.cnki.1674-8190.2023.05.10
    [Abstract] (215) [HTML] (312) [PDF 572.90 K] (411)
    Abstract:
    As an important part of the fatigue load spectrum simplification of aircraft structures, small-load omission can significantly save the time and cost of fatigue tests. However, there is no widely accepted standard method for determining the small-load omission level. In this paper, the existing small load omission levels are collected and classified, and determination rules of small load omission levels are analyzed. Then, combined with the general characteristics of aircraft fatigue load spectrum and structural materials, the links between different determination methods of small-load omission levels are investigated, and the correlation model between small-load omission levels is established, providing suggestions and references for the determination of small-load omission levels in the engineering load spectrum simplification.
    2023,14(5):85-93,100. DOI: 10.16615/j.cnki.1674-8190.2023.05.11
    [Abstract] (191) [HTML] (106) [PDF 6.19 M] (821)
    Abstract:
    This article conducts laboratory accelerated corrosion tests on simulated coastal atmospheric corrosion of 2A12-T4 aluminum alloy plates, simulating the impact of corrosion on the fatigue characteristics of aluminum alloy plates throughout the entire coastal atmospheric corrosion process from initial pitting to later erosion. Based on the principle of equivalent fatigue life degradation, an accelerated equivalent relationship between 2A12-T4 aluminum alloy plate accelerated corrosion and atmospheric corrosion is established. The research results show that the fatigue life degradation law of 2A12-T4 aluminum alloy after accelerated pre corrosion in laboratory is consistent with that of atmospheric pre Corrosion fatigue life degradation law, which is characterized by "rapid decline period"+"platform period". The first 144 hours of accelerated corrosion in the laboratory are approximately equivalent to the effect of corrosion on fatigue life in the first year of actual atmospheric environment; After 144 hours, every 36 hours of accelerated corrosion (3 cycles of immersion) is approximately equivalent to the effect of 2 years of corrosion on fatigue life in actual atmospheric environments.
    2023,14(5):94-100. DOI: 10.16615/j.cnki.1674-8190.2023.05.12
    [Abstract] (269) [HTML] (182) [PDF 5.21 M] (633)
    Abstract:
    Weak honeycomb sandwich panels are used extensively in the structural design of small and medium-sized UAVs. Due to its life cycle in long-term storage status, and the state of the structure is difficult to determine after long-term natural aging. In this paper, the bending performance of weak honeycomb sandwich panels after natural ageing is investigated. Based on the Hashin failure criterion and the stiffness degradation model, a finite element analysis model was developed to study the mechanical response and failure forms of the honeycomb core layer and skin under bending. The results show that even after long-term natural aging, bending strength increase significantly; the experimental data have good stability and the main failure modes are consistent with expectations; the results of the simulations are in general agreement with the experimental results.
    2023,14(5):101-108. DOI: 10.16615/j.cnki.1674-8190.2023.05.13
    [Abstract] (325) [HTML] (181) [PDF 4.43 M] (408)
    Abstract:
    The application of thin composite material laminate secondary bonding technology to the main load-bearing structure of small UAV wings has important engineering applications for reducing the manufacturing costs of wing box section. A single-lap structural tensile shear test was carried out using a 2mm sheet made of carbon fibre twill. The suitability of three different types of adhesive for the sheet was analysed, as well as the effect of adhesive thickness and laminate lay-up angle on the strength of the secondary glue joint, and the simulation was verified by ABAQUS software. The results show that: using SY-23B epoxy structural adhesive, the adhesive layer thickness is 0.2mm, the lay-up method is [(0/90)]8-[(0/90)]8, the bonding performance is optimal, the structural shear strength can reach 18.2MPa, to meet the small UAV stress box section bonding strength requirements, the secondary bonding formed wing stress box section has the advantages of light weight, low cost.
    2023,14(5):109-119. DOI: 10.16615/j.cnki.1674-8190.2023.05.14
    [Abstract] (255) [HTML] (103) [PDF 4.44 M] (346)
    Abstract:
    In a high temperature service environment for a long time, coatings (TBCs) generate a double layer of thermally grown oxide (TGO) consisting of an Al2O3 layer and a mixed oxide layer (MO) between the internal top coat layer (TC) and the bond coat layer (BC). Among them, the late generated MO is highly susceptible to the formation and expansion of microcracks within the coating due to its looseness and porosity and brittleness, which leads to premature spalling of the coating. Therefore, in this paper, based on the diffusion-oxidation model of double-layer TGO growth, the failure and stress evolution process of the coating interface of the coating interface under the anisotropic growth of double-layer TGO within TBCs is investigated by using the birth-death cell method, considering the nonlinear deformation behavior of the material. The results show that: the growth of MO will significantly increase the level of tensile stress at the coating interface, which will easily lead to damage and failure of the MO/TC interface in the peak area at the high temperature stage and in the center of the slope at the cooling stage; failure of the MO/TC interface causes higher tensile stresses at the peak of the BC layer and promotes the destruction of the Al2O3/BC interface from the peak to the valley during the cooling stage; after the failure of the MO/TC interface, the increase of accelerates the damage of the Al2O3/BC interface.
    2023,14(5):120-127. DOI: 10.16615/j.cnki.1674-8190.2023.05.15
    [Abstract] (229) [HTML] (159) [PDF 2.77 M] (413)
    Abstract:
    The high efficiency and low cost repair of perforation damage of aluminum honeycomb sandwich structure is of great significance to ensure the integrity of aviation equipment.In this paper, the intact and perforated aluminum honeycomb sandwich samples were designed and prepared. Four point bending failure test and finite element simulation analysis were carried out on intact, perforated and repaired composite material specimens. The experimental and simulation results show that the bending strength of aluminum honeycomb sandwich structure can be effectively restored by using composite materials bonding method . The results of finite element simulation are in good agreement with the experimental results. The simulation model can accurately calculate the ultimate load and failure mode of all kinds of samples. The simulation results show that when the damage range is ≤φ30mm (diameter to width ratio is less than 40%), the adhesive repair technology of composite materials can be applied to the damage repair of aluminum honeycomb sandwich structures of aircraft.
    2023,14(5):130-139. DOI: 10.16615/j.cnki.1674-8190.2023.05.16
    [Abstract] (102) [HTML] (425) [PDF 8.98 M] (590)
    Abstract:
    As an important force in the three-dimensional combat of the Army, the Army Aviation Corps plays an important role in fire support, three-dimensional supply, and comprehensive service guarantee. However, its construction form and operational requirements, in low altitude ultra-low altitude and low speed to perform tasks, resulting in its service environment and combat environment is more severe. Therefore, it is necessary to ensure the integrity of helicopter operational and meet the operational requirements by rationally designing the fuselage structure, improving the ability to adapt to the marine environment, and establishing a complete battle injury repair capability.
    2023,14(5):138-143,151. DOI: 10.16615/j.cnki.1674-8190.2023.05.17
    [Abstract] (195) [HTML] (364) [PDF 521.78 K] (292)
    Abstract:
    The echelon usage control of helicopters is one of the most import job in the aviation equipment support,aiming at the difficulty and lack of evaluation index in the echelon usage control, two methods of the echelon usage control are introduced, the way of echelon optimization control technology is mainly expatiated, the influences of different parameters in the echelon usage control are deduced and analyzed, and the evaluation indexes of echelon usage control are presented. Finally, a case study is carried out by using the method of echelon optimization technology, the results indicate that the method is more intuitive and more comprehensive than the ladder diagram method, and the evaluation indexes proposed are reasonable, and the research direction of the next step is clarified.
    2023,14(5):144-151. DOI: 10.16615/j.cnki.1674-8190.2023.05.18
    [Abstract] (320) [HTML] (743) [PDF 3.16 M] (430)
    Abstract:
    Aiming at the fault of a helicopter tail rotor blade fracture, the fault cause analysis is carried out by fault tree analysis method, and the bottom event analysis results are obtained. By carrying out failure analysis of the blade, the results of macro and micro fractographic analysis shows that the fracture property of the blade is low-stress and high-cycle bidirectional bending fatigue fracture. The simulation analysis of the fractographic damage evolution of flexible beam shows that when the strength value of the fiber compression direction of the flexible beam is less than 700MPa, the fractographic type is similar to that of the faulty tail rotor flexible beam. Comprehensive analysis shows that the tail rotor will produce large vibration under large fatigue load condition, and the increase of vibration intensifies the load of the tail rotor, leading to the increase of load at the root of the flexible beam, exceeding the designed bearing capacity of the flexible beam, then fatigue fracture at the root of the flexible beam of the blade.
    2023,14(5):152-161. DOI: 10.16615/j.cnki.1674-8190.2023.05.19
    Abstract:
    The phenomenon of tire hydroplaning widely exists in aircraft and automobiles. Taking aircraft as an example, tire hydroplaning will lead to a sharp decrease in the friction between the tire and the ground, increase the distance between takeoff and landing of aircraft, and further affect the flight safety. Therefore, it is necessary to carry out research on airplane tire hydroplaning. Aiming at the tire hydroplaning problem of aircraft tires, a simplified tire model was established by FEM method and verified by experiments. A water model was established by SPH method, and finally a tire hydroplaning model with the interaction of tire, water and pavement was established. The influence of different influencing factors and different tire configurations on tire hydroplaning was analyzed. The results show that, the greater the water depth, the more likely occur the tire hydroplaning, but after the water depth is greater than 6mm, the water depth on the tire hydroplaning effect is small; The greater the tire speed, tire pressure and wheel load, the more likely the tire hydroplaning; With the increase of groove width, the tire hydroplaning speed increases, but the stability decreases. The more severe the tire abrasion, the more likely it is to tire hydroplaning; The greater the number of grooves, the greater the critical water skiing speed.
    2023,14(5):162-168. DOI: 10.16615/j.cnki.1674-8190.2023.05.20
    [Abstract] (364) [HTML] (59) [PDF 2.64 M] (332)
    Abstract:
    Accurate fault diagnosis of electromechanical equipment under the condition of limited label samples is of great significance for improving the health management ability of complex electromechanical equipment. This article proposes a semi supervised bidirectional generative adversarial network (S-BIGAN) based on dual attention mechanism for mechanical and electrical equipment fault diagnosis. GAF is used to convert one-dimensional data into two-dimensional images, effectively utilizing a small amount of labeled data and a large amount of unlabeled data. Finally, bearing data is used as the validation object, and compared with algorithms such as CNN SVM and SGAN, the accuracy of fault diagnosis is greatly improved.
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    Available online:April 01, 2024, DOI:
    Abstract:
    The classic sled-type landing gear makes it challenging to take off and land in challenging terrain, with the widespread usage of rotorcraft UAVs in both civil and military domains. This research develops a two-stage buffered adaptive landing gear that is similar to a human leg in order to increase the landing area and application range of rotorcraft UAVs. An adaptive landing gear attitude adjustment strategy was proposed after researching the positive and negative kinematics of the bionic leg. A bionic quadruped hexacopter UAV landing dynamics model was established, landing dynamics simulation was carried out using the multi-body dynamics software simcenter 3D, and a comparison of landing performance with the conventional sled landing gear was carried out. The research demonstrates that the two-stage cushioned adaptive landing gear in the landing leg style and its attitude adjustment strategy can reduce roll angle by 95.69% and overload coefficient by 34.06%, proving that the two-stage cushion adaptive landing gear has excellent shock absorption and cushioning capability in the face of complex terrain.
    Available online:April 01, 2024, DOI:
    Abstract:
    This paper uses the theory of failure physics and reliability simulation analysis method to analyze the reliability of electronic controller. By establishing a digital prototype model of electronic controller, the corresponding stress analysis and fault prediction are conducted to evaluate the average time to first failure (MTTFF) reliability index of the electronic controller, and optimize the design based on the weak links found in simulation results. It is indicated that the difference between the reliability results and the theoretical calculation results are not significant, and can be used as a basis for evaluating the reliability indicators of models, reducing the cycle and cost of using physical prototypes for reliability testing; At the same time, the optimization and improvement have significantly improved the reliability design of the electronic controller, laying a theoretical foundation for subsequent model reliability evaluation and design.
    Available online:February 25, 2024, DOI:
    Abstract:
    The integral inertial particle separator is a helicopter air inlet protection device. It has excellent performance and wide application compared with other protection devices, which is of great significance to ensure the regular operation and improve the service life of helicopter engines. This paper summarizes the research progress of integral inertial particle separators, including the following aspects: 1) The classification and aerodynamic parameters of the integral inertial particle separators are introduced. 2)The research methods and their results of the integral inertial particle separators are sorted out. 3)The factors affecting the performance of the integral inertial particle separators are summarized and analyzed. 4)The future development of integral inertial particle separators is predicted. This paper can be the reference for future study and the guide to integral inertial particle separators’ optimization design.
    Available online:February 25, 2024, DOI:
    Abstract:
    The landing-gear retracting and releasing system and braking system of UAV plays a crucial role in the process of takeoff, landing, and braking of UAVs. Electrostatic hydraulic systems not only retain the advantages of traditional hydraulic systems, but also have the advantages of electric actuation. According to the working principle of the electro-hydrostatic actuator, an electro-hydrostatic system integrating the landing-gear retracting and releasing and braking functions of unmanned aerial vehicles is designed. The improved PID control method is applied to the landing-gear retracting and releasing function, and two fuzzy PID control methods are designed to apply to the anti-skid braking function. On this basis, a co-simulation based on AMESim and MATLAB/Simulink is conducted to verify the system performance, Finally, the simulation results are compared and analyzed. The results show that the designed control method can normally complete the landing-gear retracting and releasing and braking of unmanned aerial vehicles, and the control effect is good.
    Available online:February 25, 2024, DOI:
    Abstract:
    The configuration management of civil aircraft brake control system plays a key role in the process of system design and development and airworthiness compliance verification. In order to improve the configuration management capability of civil aircraft brake system, the software designed and developed can meet the airworthiness requirements, this paper introduces the concept and method of brake system control software configuration management, and illustrates how to combine configuration management with software design by means of system thinking and information flow to carry out whole-life-cycle configuration management. By combining with the requirements of DO-178C, configuration data digital management mechanism based on product configuration is established, unique data source of brake control system development is created. The result shows that a unified configuration database is established with configuration baseline management combination in which the information and status are accurately recorded strictly to ensure the real-time, traceability, integrity and effectiveness of status information, and achieve the final configuration control goal to meet the airworthiness requirements.
    Available online:February 25, 2024, DOI:
    Abstract:
    A quality risk identification and assessment method for aircraft manufacturing and maintenance based on FMEA is applied to analyze the potential failure modes and their causes of aircraft in manufacturing and maintenance, evaluate these failure modes, and formulate recommended measures for important failure modes to reduce or avoid the occurrence of failures. This paper presents a set of mapping rules for the application of DFMEA analysis results in risk identification and assessment of manufacturing and maintenance quality. The analysis scope is extended from the design end to the use and maintenance of aircraft. Through the combination of the above methods and measures, the technology realizes the analysis and evaluation of the potential failure mode, failure cause, Severity, recommended measure effect, measure coverage and repeatability in the manufacturing and maintenance process starting from the design stage, which can more scientifically and comprehensively analyze, evaluate and deal with the quality risk of aircraft manufacturing and maintenance.
    Available online:February 25, 2024, DOI:
    Abstract:
    Practice has shown that big data technology can empower the management process. As an important project in the complex high-end program of commercial aircraft development, the commercial aircraft MOC9 test project will generate a large amount of project management data during development. Therefore, it is necessary to study how to use big data technology to promote such projects to achieve project objectives. Based on the characteristics of the MOC9 test project under the commercial aircraft development program and its demand for big data management, this article conducts study on the MOC9 test project from multiple aspects such as architecture planning, data acquisition and storage, data cleaning and processing, analysis mining, and visual display, combined with big data technology processing processes and methods. The study results show that establishing a quantitative visual model for MOC9 projects through big data technology is very helpful for project managers to master the overall situation of the project, locate the root causes of problems, and identify potential risks of the project.
    Available online:February 15, 2024, DOI:
    Abstract:
    Morphing aircraft can change its aerodynamic configurations to obtain optimized aerodynamic performance. Smart material actuator and flexible skin are the key technologies of morphing aircraft. The research of actuators made of shape memory alloys, piezoelectric materials and magnetostrictive materials is introduced. The development of flexible skin based on material elasticity and structure design is analyzed. The related research issue and interests are summarized and prospected.
    Available online:February 15, 2024, DOI:
    Abstract:
    The methods of waypoint setting and point curve fitting which are not complex was usually adopted in the path planning of UAV, and the expected heading angle is given in segments. The expected heading does not automatically modified with changes in the route. The ability to automatically and quickly generate the expected heading and position is lacking. In order to solve the ability, a vector field algorithm suitable for complex flight mission path planning is studied, and a simulation verification system to verify the effectiveness of its algorithm is developed in this paper. The concept of vector field is introduced in order to design a heading angle guidance law. An aircraft at any position can smoothly fly to the desired target path along the desired heading angle, and then complete the flight task along the desired target path. The implicit function equation is used to establish the desired path vector field, and the principle and method of path planning based on vector field are geometrically analyzed. According to the Lyapunov stability theory, the boundedness of the planned path error is proved. The distance error and the heading angle error can be stably converged to 0 with the help of the heading guidance law. Taking the path planning of the altitude hold mission for a quad tiltrotor UAV as an example, the desired path of smooth flight is planned using the vector field method and the piecewise transition strategy. The verification is conducted and some simulation results are given, which show that the vector field path planning algorithm is feasible and effective for the mission flight planning of an aircraft.
    Available online:February 15, 2024, DOI:
    Abstract:
    Fault prediction technology has important application value in ensuring the reliable operation of instrument landing system and improving ATC effectiveness. Combining the operation characteristics of instrument landing system and actual operation and maintenance work, a fault prediction method of instrument landing system based on GRU is proposed. Taking heading beacons as the research object, the monitoring parameters are used as fault characteristic parameters after analyzing the relationship between their monitoring parameters and equipment operation status. Then, the GRU algorithm is used to predict the future change trend of the monitoring parameters according to their time step and significant time-varying characteristics. Finally, the probability of "failure" is calculated according to the subordinate function of the monitoring parameters, and the prediction of heading beacon failure is realized. The relative prediction accuracy of the GRU prediction model is over 95% after two years of training with the monitoring parameter data. By comparing the prediction of heading beacon failure data and normal operation data, the validity of the monitoring parameters as failure characteristics to characterize the operation of the heading beacon and the effectiveness of the GRU-based failure prediction method are verified.
    Available online:February 15, 2024, DOI:
    Abstract:
    In order to effectively evaluate the maritime emergency rescue capability of helicopters and improve their emergency rescue efficiency, it is proposed that the safety issues in the three stages of "pre-prevention--in-event response--post-event recovery" in the rescue process be taken into account in the helicopter maritime emergency rescue system.Based on the "5W1H" analysis method, the research framework was designed, and the evaluation indicators of helicopter maritime emergency rescue capability were screened through literature analysis, questionnaire survey, expert consultation and other methods, and 21 evaluation indicators were determined to build the evaluation index system of helicopter maritime emergency rescue capability. The analytic hierarchy method based on D-S evidence theory was used to determine the index weight, and the fuzzy comprehensive evaluation method was used to construct a comprehensive evaluation model of helicopter maritime emergency rescue capability. The evaluation model was applied to the rescue exercise taking the injury of offshore wind turbine maintenance personnel as an example, and the score was 86.89, and the rescue ability was judged to be "strong".The results show that the evaluation index system and evaluation model have certain practicality, and can effectively evaluate the ability of helicopter emergency rescue at sea.
    Available online:January 19, 2024, DOI:
    Abstract:
    With the widespread application of ceramic matrix composites in hot end components of advanced aero-engines, it becomes particularly important to conduct efficient and accurate nondestructive characterization of defects/damages formed during the whole life cycle. Due to the complex preparation and forming process of ceramic matrix composites and the high heterogeneity and anisotropy caused by multiphase composite, the traditional nondestructive testing technology based on the assumption of global homogenization faces many challenges. Based on the application of ceramic matrix composites in aero-engine field, the typical defect/damage types and characteristics in the whole life cycle of ceramic matrix composites were analyzed. The research progress and application of nondestructive characterization techniques of ceramic matrix composites in recent years were reviewed, the main challenges faced by existing nondestructive characterization techniques were summarized, and the future development trend was prospected.
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    2023,14(6):153-159. DOI: 10.16615/j.cnki.1674-8190.2023.06.17
    [Abstract] (178) [HTML] (25) [PDF 2.60 M] (10736)
    Abstract:
    The thermal field distribution of generator has a great influence on the failure phenomenon of the overheat protection component, which is the key parameter to be considered in the design. Based on the steady-state pressure solver and turbulence model in ANSYS software, the internal thermal field distribution of the motor under fault mode was simulated. The thermal field distribution of the stator, rotor and shell circulating oil circuit were obtained. The results show that the simulated thermal field is consistent with the actual temperature field distribution. The temperature gradient of low-melting alloy in the thermal trip mechanism is accordance with the internal thermal field distribution of the generator. It is helpful to protect the motor from overheating by changing the melting points of some key parts and the special softening temperature points of materials.
    [Abstract] (3208) [HTML] (0) [PDF 1.89 M] (6478)
    Abstract:
    Recently, with the continuous development and improvement of UAV technology, it not only plays an important role in the military field but also has been widely used in the civil field. However, the continuous reduction in the use of the UAV brings tremendous convenience to people"s life and production. At the same time, the abuse of UAV also pose a huge safety hazard to the country, society and citizens. Therefore, the demand for countermeasure and pro-tection against low-altitude drones is very strong in the military and civilian areas. This article focuses on the ap-plication of UAV in different fields, introduces the safety problems caused by UAVs flying at low altitude, and discusses the types and sources of threats. On this basis, this article focuses on the domestic and foreign anti-UAV technology in-depth analysis of the status quo, systematically on the existing anti-UAV technology and related systems, advantages and disadvantages are introduced. In addition, the future development trend of key technologies of detection and protection in low-altitude anti-aircraft UAV is analyzed and discussed based on the intelligent, integrated and autonomous research and development of low-altitude UAV systems.
    2021,12(3):161-170. DOI: 10.16615/j.cnki.1674-8190.2021.03.20
    [Abstract] (595) [HTML] (0) [PDF 8.07 M] (5089)
    Abstract:
    The process of folding and inflating the cylindrical airbag is complicated, and there are many inconveniences in using experimental methods to study its expansion process. Two different folding methods are proposed for the cylindrical airbag and the corresponding numerical analysis models are established respectively. The nonlinear dynamics software is used to study the dynamic application characteristics of the cylindrical airbag after being folded, which will affect the skin stress during the airbag expansion process. The factors of volume and internal pressure curve change are analyzed, and the influence of different folding methods and external environmental parameters on the dynamic characteristics of the cylindrical airbag is discussed. The results show that the two folding methods have their own advantages in storage space and material strength. In addition, in the environmental parameters, the external pressure has a greater impact on the stable state of the airbag after expansion, while the temperature has no obvious effect.
    2019,10(3):309-318. DOI: 10.16615/j.cnki.1674-8190.2019.03.003
    [Abstract] (1167) [HTML] (0) [PDF 1.21 M] (3898)
    Abstract:
    The Additive Manufacturing(3D Print) was widely studied and used in recent years, but there wasn"t a systematic, distinct and accurate classification about the Additive Manufacturing. The Additive Manufacturing was divided into 3 sorts and 13 sub sorts according to the category and state of the added materials and heat source of the manufacturing in this paper, as well as the principle, characteristics and trend of the each sorts of the Additive Manufacturing method were analyzed.
    [Abstract] (2488) [HTML] (0) [PDF 1.88 M] (3861)
    Abstract:
    To provide superior cruise thrust for high subsonic intermediate-long range missiles, small turbojet and turbofan engines have become the competitive focus for militarySpowers. The turbine engines for missiles are characteristic of low cost, short life, small size, high speed, low pressure ratio, severe volumetric heat release rate and various starting or ignition methods. They were widely equipped on strategic and tactical weapons, such as cruise, anti-ship and air-to-ground missiles. The development situation of small turbine engines within 100~700daN since 1970s is summarized and analyzed comprehensively in this paper, including well-known products, main technical parameters, basic features, application status and development trend. The study can provide references for the research work on missile propulsion systems. Lower cost, less fuel and fewer parts will be the future goals. The propfan engines have advantages of nice high subsonic performance and low fuel consumption, and the pulse detonation turbine engines possess high thermodynamic cycle efficiency and simple structure. They are both important development directions of advanced turbine engines for missiles.
    2014,5(1):109-115. DOI:
    [Abstract] (3904) [HTML] (0) [PDF 2.89 M] (3531)
    Abstract:
    For free turbine turboshaft engine with high thermodynamic parameters and high-bleed, a new turboshaft performance calculation model which considers bleed position and cooling air expansion work. The model of air bleeding in the middle of the compressor corrects the flow balance and power balance at the same time. The turbine cooling model considers the cooling air expansion work. The calculation results obtained by the new model are analyzed and compared with that of simple turbine bleed and cooling model, which proves that the new model can obtain the influence of the amount of bleeding and bleeding position to the performance of turboshaft engine. The new model are close to the true physical process of turboshaft engine, and can offer input to the air system.
    2018,9(1):99-106. DOI: 10.16615/j.cnki.1674-8190.2018.01.013
    [Abstract] (2148) [HTML] (0) [PDF 1.77 M] (3367)
    Abstract:
    A heavy-duty quadrotor UAV which has the features of foldable, light weight, high strength is designed according to the performance requirements. The maximum payload of this UAV is 10kg. The finite element model of the quadrotor structure is established. Static and buckling analysis of the UAV arm and central plate are carried out based on the actual loading cases. The layer structures of the arm and central plate are optimized. The strength, stiffness and stability of the UAV are verified. Compared with the initial layer structures, the weight of the arms drops by 43%, and the weight of the central plate drops by 35%. The weight of the UAV structure drops by 560 grams. The lowest weight requirement is achieved. An UAV static test platform is built, and the structure static loading test is completed. The strain relative error between the test value and the analysis value is less than 15%. The reliability of the UAV finite element model and the optimized layer structures is verified.
    [Abstract] (1806) [HTML] (0) [PDF 562.11 K] (3226)
    Abstract:
    There are a great deal of influence on many fields of society as a result of the new round of technological revolution and industrial revolution centered on artificial intelligence. All the aerospace powers have conducted many useful experiments and explorations in the combination of artificial intelligence and aerodynamics. The development history and status quo of artificial intelligence technology are reviewed in this paper, the applications of artificial intelligence in wind tunnel test, numerical calculation and flight test are discussed in the background of big data era, the role of artificial intelligence in assisting mass aerodynamic data analysis and knowledge discovery is analyzed in detail, the application values of artificial intelligence in aerodynamic modeling and advanced aircraft design are investigated, the future development direction and challenges of combination of artificial intelligence and aerodynamics are prospected.
    2013,4(2):158-163. DOI:
    [Abstract] (3619) [HTML] (0) [PDF 4.91 M] (3038)
    Abstract:
    Weight is one of the most important performances for the aviation productions. The most effective approach to weight saving is developing the lower density material. Introduce advanced Al-Li (Aluminum-Lithium) alloy with lower density, higher tensile strength, better damage tolerance etc. Compare to conventional aluminum alloys and trade-off study with advanced composites. Analysis the properties of 3rd-generation Al-Li alloy and the applications on advanced aircraft. Provide the proposals of applications in civil program. The research can be the reference of materials selection and weight saving for commercial aircraft, and benefit extending applications of Al-Li alloy.
    2020,11(2):147-158. DOI: 10.16615/j.cnki.1674-8190.2020.02.001
    [Abstract] (1504) [HTML] (0) [PDF 3.27 M] (2822)
    Abstract:
    To reasonably and efficiently guide the safe, reliable and economical operation of civil aircraft, we investigate the main contents and explore the application in operational reliability analysis and feedback of S5000F, i.e., international specification for in-service data feedback, which is organized by AeroSpace and Defence Industries Association of Europe (ASD). The compilation background and purpose of S5000F specification are first elaborated, and the main contents and the relevant business processes in the S5000F specification were then introduced. We finally discussed the application of S5000F specification in the operational reliability analysis and feedback of civil aircraft. In this paper, the S5000F specification is comprehensively interpreted, and its application in the operational reliability of civil aircraft is studied. In this case, we further extend this specification to the design phase and service phase of civil aircraft. The efforts of this study provide effective guidance for the life cycle management of civil aircraft.
    2013,4(2):241-246. DOI:
    [Abstract] (2368) [HTML] (0) [PDF 2.31 M] (2665)
    Abstract:
    In this paper, an approximation method is presented for calculating the wing load envelope and using to size the wing box in wing strength primary design phase. It is found that the triangle weight load distribution is better than other distributions in simulating the wing weight. Furthermore, this paper investigates the characters of critical over loading and centralized loads for large civil aircrafts. An approximation method for calculating the wing load envelope of bending moment and shear force in flight is proposed by combining the Schrenk lift distribution and triangle weight distribution. Then, the proposed method is validated by wind tunnel data of wing shear forces and bending moments.
    [Abstract] (1693) [HTML] (0) [PDF 2.40 M] (2603)
    Abstract:
    Reducing the weight and increasing the torsion stiffness are the two main pursuits in propeller blade structure design. And the application of composite materials has improved the designability of propeller structure. In this paper we present an optimization process on a composite propeller blade, in which the composite layup numbers and angles are optimization parameters, the strength and bending stiffness are optimization constraints and the weight and torsion stiffness are optimization objectives. Non-dominated Sorting Genetic Algorithm is adopted to get a Pareto front of the two objectives. Results show that the optimization method is effective.
    Abstract:
    Bayesian Network(BN) is a mathematical model based on probabilistic reasoning, which have a great advantages in solving the uncertainties between complex systems. Because of the complexity and uncertainty in air-combat, aiming at the problems in effectiveness evaluation, combined with the air-combat theory and reality. The effectiveness evaluation model of air-combat based on BN is build, the effectiveness evaluation method of air-combat based on BN is given, and simulation analysis is carried out. The results show that the model is valid and accurate, and the method has a strong ability to learn and reasoning.
    2021,12(4):80-89. DOI: 10.16615/j.cnki.1674-8190.2021.04.09
    [Abstract] (478) [HTML] (0) [PDF 4.02 M] (2407)
    Abstract:
    The effect of thermal load in the creep feed grinding have important effect on the surface quality for ma? chining the tenon teeth of turbine blade. In this paper,the effects of grinding parameters on grinding forces and temperature in grinding DD5 single crystal alloy are investigated by experiments. The influences and formation mechanism of DD5 creep-feed grinding forces and temperatures are analyzed,and a mapping model between thermodynamic effect and grinding parameters is established and verified. The experimental results show that the grinding depth has the greatest influence on the DD5 creep-feed grinding force and temperature,following by the grinding wheel speed,and the feed velocity of work-piece has less influence on the grinding forces and temperature. With the increase of the grinding wheel speed,the grinding force is decreasing,and the grinding temperature has an in?creasing trend. With the increase of feed velocity and grinding depth,both the grinding force and temperature are of increasing trends. Increasing the feed velocity and reducing the grinding depth on the premise of satisfying the material removal rate can avoid the larger grinding thermodynamic coupling layer on the DD5 grinding surface.
    2014,5(1):1-6. DOI:
    [Abstract] (3026) [HTML] (0) [PDF 6.43 M] (2387)
    Abstract:
    Fuel tank damage caused by hydrodynamic ram has became increasingly widespread. Summary and analysis of the research of hydrodynamic ram in recent decades provide a reference for future research work. Hydrodynamic ram research has an early start, early experiment and theoretical analysis formed the theoretical basis. With the progress of the test apparatus and the introduction of finite element method, test results has became more and more accuracy, hydrodynamic ram effect research entered a new phase. But for the hydrodynamic ram effect, there are so many problems, they will be the focus of future work.
    2020,11(2):159-166. DOI: 10.16615/j.cnki.1674-8190.2020.02.002
    [Abstract] (1316) [HTML] (0) [PDF 1.20 M] (2387)
    Abstract:
    High Altitude Long Endurance (HALE in short ) UAV has made great development since its birth and participation in war. With the expansion of combat mission to high-risk confrontation battlefield, HALE fly-wing UAV has become a hotspot in the world today. In this paper,the requirements of HALE fly-wing UAV for turbofan engine are described, effect of key design parameters on the performance of turban engine is analyzed based on the basic principle of aero engine, the key problems and research progress of HALE fly-wing UAV are summarized. This paper has important reference value of the selection of turbofan engine for HALE fly-wing UAV and the improvement of its adaptability design.
    2021,12(4):44-51. DOI: 10.16615/j.cnki.1674-8190.2021.04.05
    [Abstract] (997) [HTML] (0) [PDF 5.62 M] (2286)
    Abstract:
    Rotor airfoil design involves multi-point and multi-objective complex constraints. How to significantly improve the maximum lift coefficient and maximum lift-to-drag ratio of rotor airfoil is a fundamental problem to be solved urgently in the development of high-performance helicopter rotor blades in the future. Novel flow control technology is the most potential method to achieve the high lift enhancement and drag reduction of rotor airfoil. Based on the classic OA312 rotor airfoil, this paper conducts the low-speed wind tunnel test of high lift enhancement and drag reduction of rotor airfoil using Co-flow Jet concept (CFJ) with zero mass and high negative pressure at the leading edge. The rotor airfoil CFJ dynamometric model driven by the micro ducted fan group is designed. The influence of basic parameters such as the injection size, suction size and suction surface translation on lift enhancement and drag reduction is studied. The ratio of jet velocity to mainflow velocity is qualitatively discussed. The optimal value range of key parameters of CFJ rotor airfoil is given. Results show that compared with the OA312 baseline airfoil, the CFJ rotor airfoil can significantly reduce drag coefficients at low angle of attack, and even achieve while the zero-lift pitch moment is basically unchanged. The CFJ rotor airfoil can significantly increase the maximum lift coefficient and the stall angle of attack at high angle of attack. The maximum lift coefficient can be increased by about 67.5%, and the stall angle of attack is significantly delayed by nearly 14.8°. Research results verify the technical feasibility of applying CFJ technology to significantly improve the key performance of rotor airfoil and provide a new feasible solution and idea for the design of high-performance rotor blades in the future.
    [Abstract] (1315) [HTML] (0) [PDF 1.78 M] (2256)
    Abstract:
    In order to calculate the contact force of the flight lock mechanism, the function and main design basis of flight lock are firstly introduced in this paper. Then the working principle of the flight lock for a specific civil airplane is illustrated, following with the analysis of its force transmission path. Then three calculation methods (engineering method, rigid multi-body model, and flexible multi-body model) are used to compute the contact force between crank and rocker arm. Finally the three calculation methods are compared and analyzed to find out the reasons of the differences between the contact forces for each methods. The results shows that the arm variation caused by mechanism banking leads to the difference between the forces calculated by engineering method and rigid multi-body model. On the other hand, structure deformation is the main factor that causes the difference between the forces calculated by rigid multi-body model and flexible multi-body model. These analysis results can be consulted for the structural design of civil airplane’s flight lock.
    2018,9(3):297-308. DOI: 10.16615/j.cnki.1674-8190.2018.03.001
    [Abstract] (1289) [HTML] (0) [PDF 3.91 M] (2219)
    Abstract:
    This paper focuses on the research on the status of adaptive wing and summarizes from the adaptive compliant leading edge, the adaptive compliant trailing edge and the variable thickness wing, respectively. And the key technology that adaptive wing needs to be solved urgently is put forward, which can provide some technical reference for the design and implementation of adaptive wing structure.
    2013,4(3). DOI:
    [Abstract] (2818) [HTML] (0) [PDF 3.09 M] (2208)
    Abstract:
    According to the folding wing morphing aircraft, designed a planetary gear train of folding mechanism, which suit assembly in the small space of morphing aircraft. On the basis of the systematic study of the planetary gear design goals, variables and constraints, describes the floating-point coded genetic algorithm, using the MATLAB optimization toolbox to optimize its main parameters. Research shows that the structure weight loss 16.7% compared with the safety coefficient method, achieve the minimum weight of the folding mechanism in the case of meeting the design specifications. Therefore the floating-point coded genetic algorithm optimization solution for planetary gear mechanism design is an effective optimal design method.

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