Abstract:
In order to solve the problems of thermal deformation and thermal residual stress of fiber reinforced polymer (FRP) circular pipe in engineering, a calculation method of equivalent thermal expansion coefficient and thermal residual stress of FRP tube with arbitrary ply was proposed. This method is a three-dimensional elastic theory considering lamination effect and three-dimensional constitutive relationship of anisotropic material. The correctness of the theory was verified by comparing and analyzing with multiple groups of data of the test and ANSYS numerical model in this paper. Based on this theoretical model, firstly, the equivalent thermal expansion coefficients of many kinds of laminated FRP circular pipes were studied. Secondly, combined with the strength ratio equation of Hashin failure criterion, the strength failure of FRP tube caused by thermal residual stress was analyzed. The results show that the influence of FRP tube ply angle on the equivalent thermal expansion coefficient is different in the thermal shrinkage stage and thermal expansion stage, and there is a laminated mode with zero equivalent thermal expansion coefficient; The diameter thickness ratio only has a great influence on the equivalent radial thermal expansion coefficient, but has no influence on the equivalent axial thermal expansion coefficient; Temperature difference and direction affect the failure mode and location of FRP tubes. The strength failure of FRP tubes caused by thermal residual stress is matrix failure.