hydrostatic stress这个结果是什么意思？

forcejiwd

今天在学习ncode designliafe的时候，做了个例子，过程和结果如下图。


" Y5 ~3 H" O- l' ]' [  @+ i3 R4 H' N第二幅图中是什么含义？请教高手指导
/ n* ?3 r1 r& i' d

zhangpengwei

这个是多轴疲劳的安全因子图，在直线一下是安全，在曲线以上安全系数小于1

yangyanghust

从help文档找到这样一段
, W" m8 Y5 K; Z   Summary

9 L0 a, V3 a) B2 s( a8 V7 Z        The Dang Van method is designed to provide a safety factor calculation for
        multiaxially loaded components in the endurance regime (large number of
        cycles to failure). The theoretical basis can be summarized as follows:
9 s2 i' E2 ~; W% S: b$ M
1 ^& x+ o1 |( @+ I          * Fatigue crack initiation normally occurs due to repeated plasticity on shear
            planes in individual grains.

          * The most important factor as to whether a crack will propagate past the first
# _, L- w5 l) i+ f9 g2 E+ R0 _& }            grain and go on to cause fatigue failure is therefore the microscopic shear
0 t( @$ z. A5 P& q+ l' _* f            stress in critical grains.

2 v7 |- j) W6 _          * The ability of a shear crack to propagate is modified by the hydrostatic stress
            (which can increase damage by opening existing cracks).         
    * The state of stress in a grain where repeated plasticity is occurring will be
' w' E$ Q+ Y9 G7 P9 K* Y# r, y+ a            affected by a process of shakedown.