Strain Rate Impact into the Stress and Strain Values at Break of the PA6 GF30-Reinforced Polyamides

The study of the strain rate effects on the PA6 glass fiber-reinforced polyamide, in this specific case, PA6 GF30 (30% reinforced glass fiber), is critical due to composites widely used in automotive applications where the velocity of loading can vary significantly. Some insights into material safety under high quasistatic strain rate regime are given by understanding tensile behavior with focus on strain and stress at break. For this, using injection molding, dog bone samples were subjected to tensile tests at different strain rates, using a precise displacement control and extensometer to record the engineering stress–strain. The results demonstrate that higher strain rates increased the stiffness and strength of the specimen, shifting the stress–strain behavior to higher stress at break due to the reduced time for the polymer relaxation. However, the strain at break decreases under rapid movement, indicating the fact that the specimens exhibited reduced ductility. The results indicate a pronounced strain rate sensitivity that needs to be evaluated and considered for the design and failure mechanism of the components made of PA6 GF30, highlighting the necessity of strain rate specific mechanical characterization for accurate evaluation of performance under high quasistatic strain rate load cases, leading to a more safe and reliable design.