An improved stress recovery technique

Many techniques have been proposed over the years to obtain an accurate stress field from displacement-based finite element solutions. This is not easy since usually low-order (linear) finite elements are used. Therefore, computed finite element stresses are also of low order. In this MSc project we investigated a stress recovery procedure for linear tetrahedra by following the work of Payen and Bathe. Compared with existing recovery techniques, this procedure gives more accurate stress fields, is simpler to implement, and can be applied to different types of elements without further modification.

Stress recovery applied to a pressurized sphere
The error in stress with respect to the element size $h$ shows that the new technique has a higher convergence rate than that of standard FEM computed stresses.

Related publications

  • R. Sharma, J. Zhang, M. Langelaar, F. Keulen, and A. M. Aragón. "An improved stress recovery technique for low-order 3D finite elements." International Journal for Numerical Methods in Engineering 113.1 (2017), pp. 88–103