应力输出请教？

zou007

本人对力学方面的知识不怎么了解，对ansys中的应力输出的以下选项很多不太懂，那位大虾能不能帮忙解释一下下面各项的意思？不胜感谢！
X-Component of stress
Y-Component of stress
Z-Component of stress
XY Shear stress
YZ Shear stress
XZ Shear stress
1st Principal stress
2nd Principal stress
3rd Principal stress
Stress intensity
von Mises stress
Plastic equicalent stress
Stress state ratio
Hydrostatic pressure