, and why second order full integration is suitable to get this result. Besides, what

[R.Guo]

How to calculate stress concentration in FEM, and why second order full integration is suitable to get this result. Besides, what the different for load-loading vs displacement-loading to calculate the stress concentration?

 

[FEA way]

For stress concentrations mesh should be fine and regular enough to capture gradeints around small notches. Second order elements are much better for this purpose than first order because they represent geometric features like curved edges with no need to use many linear elements. They also have more nodes which means higher precision. What’s interesting linear elements are less vulnerable to mesh distortion.

When it comes to full vs reduced integration, it’s not that obvious. Often results with reduced integration elements are not worse or even better than with full integration elements (and computational cost is lower). But with reduced integration you must be aware of the risk of hourglassing.