Fatigue life and crack growth rate of carbon fiber reinforced polymer composite at elevated temperature environment: An experimental study

Abstract

AbstractThis study focuses on a plane‐weaved bidirectional (0°/90°) carbon/epoxy composite, known for its excellent mechanical properties. The composite was manufactured using a vacuum bagging resin infusion microwave curing process, incorporating carbon fiber as the reinforcement material and a thermosetting epoxy with a hardener as the binding material. Mechanical, fracture and fatigue crack growth characteristic of carbon fiber reinforced polymer composites were experimentally evaluated under elevated temperature environment. Fatigue life cycles were calculated at ambient and elevated temperatures by varying stress ratio values (R = 0.1, 0.3, 0.5, and 0.7) using a dynamic universal testing machine. The Fatigue crack growth tests were performed on four‐layer composite laminate in different thermal environments at a constant stress ratio of 0.1. The study establishes relationships between stress and the number of cycles at different UTS percentages and stress ratios. The effect of environmental temperature on crack growth rate was investigated to predict fatigue Paris parameters and the value of Paris constant C and slope m were evaluated. Mechanical properties, fatigue life cycle, and fatigue crack growth of the composites exhibit variations across different temperature ranges. Post‐failure microstructural characterization techniques were applied to observe the failure patterns, fiber pull‐out and matrix cracking at different scales in composite specimen at different temperature ranges. The presented studies provide insights into the performance and durability of CFRPCs under varying thermal conditions, for aerospace applications.