The phenomenon of stiffness deterioration(progressive damage) beyond the peak stress has been observed in cyclic loading tests of coals,rocks,concretes,soils and sands.

Considering the examination result,the deterioration depth and omission depth of concrete have a remarkable increase in connection with the age,and the amounts of change are 0.

At the same time, it was studied that the effect of hop storage index (HSI) and deteriorative degree on evaluating hop freshness for hops which stored for different time.

In order to overcome the imperfection and insufficiency of the conventional evaluate methods,the concept of relative degree of inferiority is introduced and a model based on the fuzzy judgment and relative inferiority degree is established.

Research on behaviors of frame-shear wall structures based on stiffness degradation;

In this paper,a new rate-dependent concrete elasto-plastic damage model for simulating the mechanical behaviors of concrete is established by introducing the effect of strain rate,damage variable and stiffness degradation variables.

The real stiffness of frame in different deformation phases was determined according to experimental data,and the stiffness degradation coefficient was adopted to revise the stiffness of each floor.