机械零件的强度.ppt

文档介绍：Chapter 3 Failure Theories and Material Strength
Key Terms:
bulk strength 整体强度
surface strength 表面强度
brittle material 脆性材料
ductile material 塑性材料
Outlines
Theories of Failure
Bulk Strengths of the ponents
Surface Strength of the ponents
Theories of Failure
Key Terms:
uniaxial stress 单向应力
biaxial stress 双向应力
triaxial stress 三向应力
yield strength 屈服强度
ultimate strength 极限强度
shear strength 剪切强度
Bulk Strength of the  ponents
Loads and Stresses
Loads:
force 力
bending moment 弯矩
torque 扭矩
static load 静载荷
repeated load 循环载荷
impact load 冲击载荷
2) Stresses:
tension stress 拉应力, compression stress 压应力,
shear stress 剪切应力
static stress 静应力
varying (fluctuating) stress 变应力 repeated alternating (pulsant) stress
r=0 脉动循环变应力
completely reversed (symmetrical) stress
r=-1 对称循环变应力
Reversed Stress
Pulsant Stress
Fig. Typical Stresses
r = 0
r = +1
r = -1
3) Parameters of fluctuating Stresses
max, maximum stress 最大应力
min, minimum stress 最小应力
m, mean stress 平均应力