Title: Non-Linear Behaviour of Towpreg Tensile Modulus for Automated Fiber Placement (AFP)
Authors: Massimo Carboni and Mehdi Hojjati
Abstract: Modern composite manufacturing techniques using Automated Fiber Placement (AFP) technology incorporate simulations and Finite Element Analysis (FEA) prior to manufacturing of the part. In order to have acceptable results from the simulation, the material properties of uncured towpreg is required. One of those properties is tensile modulus. This study investigates the linear and non-linear behavior of the tensile modulus of a single uncured carbon fiber towpreg. Tensile tests were performed, and the force and displacement were monitored. Stress-strain curves were generated, and the modulus was calculated. It was observed that the modulus at the beginning of the load is nonlinear and as the load increases, it becomes constant and closer to the cured laminate. Additionally, investigation was made to determine the cause for the non-linear modulus through studying the fiber waviness of the uncured prepreg by microscopic observations. Comparisons were made between the waviness of untested and uncured carbon fiber tows with the tested uncured carbon fiber tows.
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Publication Date: 2020/06/01
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