MATERIAL REMOVAL SIMULATION OF AUTOFRETTAGED COMPOUND TUBES

Real loading- unloading behavior of an A723-1130 MPa high-strength steel alloy incorporated in the variable material properties (VMP) numerical algorithm to predict residual stresses resulted from autofrettage and shrink fit in two autofrettage compound tubes design philosophies. Using an analytical method, the numerical solutions were developed to estimate residual stresses induced by bore material removal via machining. Using developed VMP code and isotropic hardening rule in both autofrettaged compound tube design philosophies, residual stresses resulted from shrink fit and autofrettage processes and via post machining, were calculated. Machining process simulation was performed for 10 mm bore material removal. ANSYS commercial FEM software was used for validating the results of VMP code. The results of VMP method and ANSYS were in good agreement with each other. Finally with the help of recorded real unloading behavior of A723-1130 MPa high-strength steel alloy, also aforementioned simulations were performed on various tubes. The material removal simulation was modeled for 20 mm material removal from the bore.

Keywords:

Autofrettage , Shrinkfit , Residual stresses , Compound tubes , Material removal , Real unloading behavior