Finite Element Analysis of Linear Thermal Expansion Coefficients of Unidirectional Cracked Composites

The linear thermal expansion of coefficients of unidirectional composites are systematically studied by the Finite Element Method (FEM). Thermal expansion coefficients are first determined for composites with perfectly bonded interface between fiber and matrix. Results are compared with available experimental and analytical results. Next cracks caused by debonding along the fiber-matrix interface are studied to investigate the effects of interface cracking on the transverse thermal expansion coefficients. Due to the presence of cracks and shearing along the debonded interface, the principal direction of transverse thermal expansion changes. The obtained results showthat the transverse thermal expansion coefficients change significantly due to the presence of thin interfacial cracks.