Abstract:

In view of the compilation of airplane load spectrum having close relation with the national conditions and the compilation method subordinate to knowledge property category, in the research, we find another way, rely on our own efforts and have set up a technical approach to airplane load spectrum compilation with China characteristics. With the help of equivalent life probability distribution and under the condition of satisfying a high confidence level (above 90%), we put forward a compilation theory of median stochastic fatigue load spectrum. Median stochastic fatigue load spectrum agrees to the scatter factor method of determining airplane service life. It can truly display the load time history of structural natural modality in the real service. It keeps a one to one correspondence relation of load time and every state parameter. When fatigue testing is done, median load spectrum can authentically replay the whole fatigue damage procedure of structural key parts depending on the time of crack generation, crack propagation and final fracture.

Key words: high confidence level, median, load-spectrum, compilation theory