Abstract
INNEGRA® fibers are synthetic polyolefin-polypropylene fibers with a high modulus widely used in aerospace, automotive, and marine industries. This study investigates the high-velocity impact behavior of woven INNEGRA®/Epoxy composites through experimental and numerical methods. The composites were fabricated using a vacuum infusion process with two thicknesses configurations: two and four layers. Strength properties were evaluated according to ASTM D3039, ASTM D5379, and ASTM D3410 standards, and engineering constants were determined using a representative volume element (RVE) approach. High velocity impact tests were conducted using a gas gun across various velocities, employing projectile with hemispherical and, conical nose shapes. Numerical simulations were performed using a Macro-homogeneous model, where each layer was modeled as an orthotropic equivalent layer. The failure model was based on a maximum strain criterion, predicting failure when strain exceeded the ultimate strain. Strong agreement was observed between experimental and numerical results. The study demonstrates that stress-based criteria, such as the Hashin model, are unsuitable for predicting the high-velocity impact response due to the high ultimate strain and low strength of INNEGRA®/Epoxy composites. Key parameters, including ballistic limit, residual velocities, the effect of layers count, projectile nose shape, absorbed energy and damage morphology were comprehensively analyzed. Results indicate that woven polyolefin-polypropylene composites are highly effective for energy-absorbing applications due to their low density, high ballistic limit velocity, and significant deformability under high-velocity impacts.
Get full access to this article
View all access options for this article.