Elastic–plastic thermomechanical response of composite co-axial cylinders

Abstract A new method is developed in this paper to A strong matrix can raise the compressive stresses in the deal with the thermomechanical response of continuous fiber, and the tensile circumferential and axial stresses in fiber-reinforced composites. Treating the matrix as an the matrix. elastic-perfectly plastic solid, the analytical formulae of the deformations and stresses of the matrix are obtained from the plasticity theory, axisymmetric equilibrium equation, and stress–strain and strain–displacement relations. The fiber is taken to be an anisotropic, elastic material, and the Introduction formulae calculating its deformations and stresses are also presented. The boundary conditions and the consistence of Due to different material properties of the constituents of deformations and stresses between the fiber and matrix, the composites reinforced with continuous fibers, different and between elastic and plastic regions of the matrix are deformations of the constituents will occur for the com- employed to determine the unknown constants in the posites subjected to thermal or thermomechanical loads analytical formulae. With the developed method, the induced during processing or in-service exposure. They thermomechanical stress distributions in composites rein- may cause large thermal or thermomechanical stresses and forced with circumferentially orthotropic, radially ortho- lead to composite failure or property degradation. There- tropic and transversely isotropic fibers are investigated, and fore, thermal or thermomechanical analysis of the com- how the elastic-perfectly plastic property and different posites has attracted a lot of attentions and some methods materials of the matrix affect the thermomechanical have been developed. response of the composites is discussed. For the thermo- The concentric cylindrical model is the most popular mechanical loads and composite systems given in this one used in thermal and thermomechanical analyses of paper, the elastic-perfectly plastic property of the matrix fibrous composites. Early in 1980, this model was can reduce the compressive stresses in the fiber, and the employed to deal with the static problem of the linear tensile circumferential and axial stresses in the matrix. of thermoel for a com r