Estimation of elasto-thermodynamic damping in the Al/SiC system using a finite element approach

It is known that reinforcement of a ductile metallic matrix with stiff ceramic particles enhances damping arising from various sources. Among them elasto-thermodynamic damping can arise due to the inhomogeneity in stress distribution in a metal matrix composite which is theoretically predictable using the second law of thermodynamics. A literature review shows earlier studies developed analytical models but assumed a spherical shape for the particle and the metallic matrix. In this study, a novel unit cell model is developed that is based on a finite element method which predicts the elasto-thermodynamic damping capacity of metal matrix composites under uniaxial cyclic loading. The model can account for the particle’s size and morphology features such as aspect ratio and stress concentration effects. It is also capable of predicting the effects of particle defects such as particle debond, particle breakage, etc., and the presence of process-induced defects such as voids and cracks in the metallic matrix on the composite damping characteristics.