Further,the sinkage stiffness of the door is analyzed by using FEM,the result indicates that the deformation is graver near the top left comer of the door and the lower edge of the window,these parts should be enforced to optimize the structure.

Fatigue damage accumulation model based on stiffness degradation;

Based on damage theory and strain equivalent hypothesis,a fatigue model is presented in which the residual strain and stiffness degradation are included.

The research analyzes variation features between ground reaction forces of people enduring and joint reaction force and torque of joint on the ankle and knee and hip, and search changes of people s lower extremity stiffness under 8 different height landing and buffering experiences.

It points out that there is a basic corresponding relationship between sruface subsidence velocity and rock-burst, which has inverse-spring effect, wave band effect, lagging character, he rules of the relationship was summarized.

According to experiment results, the characteristics of subsidence velocity is analyzed, and the view is presented that maxinum subsidence velocity is the function of the mining area.

The aircraft landing sinking speed is one of the major parameters during undercarriage design and undercarriage strength inspection of the aircraft design typing flight test.

The effect of sinking depth on lighting performance of the solar energy-saving greenhouse;

Comparing with the calculating result of actual criterion,this article also presented the proper sinking depth of the single ling sinking piles,which can be used for reference in future project.