Temperature Effect on the Properties and Response of Composite Materials and Plates

The paper illustrates the effect of temperature on composite material properties and its influence on the response of composite plates. Two composites considered include laminae with uniaxially oriented and with in-plane randomly oriented fibers. Analytical solutions are presented for a uniformly heated large-aspect-ratio plate deforming into a cylindrical surface. The solutions are demonstrated for thermal buckling and natural frequencies for the cases of controlled loading and controlled displacements. Micromechanical residual and lifetime thermally induced stresses at the interface of fibers and matrix are assessed to predict a possible onset of local damage after the curing and during lifetime. The material considered in numerical examples consists of silicon carbide fibers and a titanium alloy matrix. The moduli of elasticity and shear as well as the coefficients of thermal expansion of this composite are significantly affected by temperature. The thermally induced microscopic radial stress at the fiber–matrix interface is high, so it should be monitored in silicon fiber titanium matrix composites to avoid the onset of local damage. In conclusion, accounting for the effect of temperature on material properties is highly desirable since it produces more accurate solution than those utilizing the properties at the room temperature.