Rate-Sensitive Micromechanical Damage Model for Brittle Solid

Abstract

A micromechanical damage model for a brittle solid capable of taking into account the effect of high loading rate (in the form of stress-rate) is presented. Although, this model is applicable to any particulate brittle solid, concrete is given primary consideration. An existing self-consistent rate-insensitive model is modified and extended to induce rate dependency of concrete type material with preexisting damages (cracks). The variations of several fracture mechanics parameters of solid, viz., stress intensity factors, fracture toughnesses, etc., under the influence of high loading rates were given primary consideration. The process of crack evolution in a particulate cracked solid under tensile and compressive stress-field has been thoroughly considered along with all possible situations that may arise. Crack kinking and nucleation are considered for both tensile and compressive stress-field. The resulting rate-sensitive micromechanical damage model has been codified and several experiments have been replicated to validate it.