Stress recovery based on smoothed basic solutions

Postprocessing techniques in traditional finite element method, smoothing process is always adopted after differential operation, such as the nodal average method, SPR, etc. The difference between them is mainly on how to smooth the discontinuous stresses. In order to enhance finite element stress accuracy, a new method is proposed in this paper. First, the basic solutions are smoothed under a small element patch with polynomial fitting method; as a result, the basic solutions get differentiability on element boundaries. Then, the stress value on the node can be calculated though differential operation. According to this way, the stress value on nodes' can be given over the whole domain. The numerical examples illustrated the applicability and higher accuracy can be achieved. Moreover, this method needs less computing time and can be used widely.