1.AVIC Aircraft Strength Research Institute,Xi’an 710065;2.China
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.