The result of the effective strain and the effective stresss in cavity die circular section is caculated by simulating the cup drawing in different states cosidering strain, stress and thickness changes.

Through FEM numerical simulation of flanging process which was carried out with ABAQUS software,the cognition that flanging process can be divided into 4 stages,the dynamic process of flanging,the method of computing for the prepared hole-diameter,the material thickness transformation of deformation area and the characteristic of effective stress distribution,etc.

The effective strain and effective stress are introduced under the condition of axial symmetry.

Simulation on equivalent stress in soldered joints of QFP devices with different leads;

Expression on equivalent stress and equivalent strain of wall rock state of tunnel;

Simplified calculation on equivalent stress of vortex dedendum under the effect of uniform internal pressure;

Mathematical model for equivalent moment and moment of inertia of a planar linkage;

Another concept named equivalent suction is put forward after magnitude of suction as well as correspondiog effective area of matric suction and tension suction on particle surface are taken into considerati.

Then effective area on particle surface,both for matric suction and tension suction,as well as relation between saturation degree and various types of suctions or corresponding equivalent suctions are established for different contract angles.

To avoid the difficulties in the determination of soil sucti,otnhe so-called equivalent suction has been advanced recently.