Modeling non-linear rate-dependent behavior in fiber-reinforced composites

Abstract

The rate-dependent behavior of AS4/PEEK (APC-2) thermoplastic composite has been characterized over a wide strain rate range (10 × 10 −6 to 1000s −1). The low to moderate strain rate experiments were conducted with a servo-hydraulic testing machine, while the high strain rate experiments were conducted with a Split Hopkinson Pressure Bar. Two rate-dependent models are introduced to model the material response. Both models are developed by using a one-parameter plastic potential function to describe the non-linear behavior. Off-axis composite specimens are tested in simple tension at different strain rates, and the results are used to determine parameters of these models. Predictions of these models are shown to agree fairly well with the experimental results over a wide range of strain rates.