Improvement of Stress and Error Estimation by Patch Equilibrium in Isogeometric Analysisic analysis

A method for error estimation of isogeometric analysis of plane stress problems, based on stress recovery by using the super convergent properties of the Gauss points, was introduced. In this paper, a different approach for improvement of stresses based on the satisfaction of equilibrium equations by taking into consideration of two elasticity problems is followed and the effect of the number of the Gauss quadrature points is studied. In this approach, the equilibrium equations are satisfied for each patch of the isogeometric analysis model and it has been shown that the recovered stresses are more accurate than the previous method where the super-convergent properties were used. To demonstrate the performance and efficiency of the method a couple of elasticity problems are considered and the obtained results are compared with the previous method and exact solutions. The results indicate that the suggested method can be employed for error estimation and stress recovery in the isogeometrical analysis method.