On The Estimation of Residual Stresses by the Crack Slitting Method Usingthe Eigenstrain

The slitting method was used to measure the profile of residual stresses in fiber-matrix composites. The ply configuration of the composites used in this study is [904/04]S. The stress measurements involved successively deepening a narrow slit through the plies, and measuring the trains with a surface strain gage. In this paper a new method has been introduced based on the eigenstrain concept. This method has been used instead of the traditional slitting method, which obtained residual stresses directly from recorded strains. In this new method, eigen strains have been calculated using a finite element method. Then, the residual stresses are obtained by using the eigenstrains. In the traditional method the as predicting residual stress field cannot satisfy the compatibility equations. The new method has solved the problems of the traditional slitting method.

Keywords:

Slitting , Eigen Strain , Residual Stress