Role of matrix in viscoplastic behavior of thermoplastic composites at elevated temperature

The viscoplastic behavior of thermoplastic composites at high temperatures are studied using a constitutive matrix model. The model relies on a modified Bodner and Partom flow rule to analyze the composites' elastic properties, such as volume, fiber and matrix, which are expressed in terms of the rule of mixture equation. The new flow rule equations are then solved by means of the direction iteration method and other related techniques. Results indicate that it is possible to predict the composites' viscoplastic behavior using only the viscoplastic properties of the matrix.