Damage mechanism and residual tensile strength of CFRP laminates subjected to high-velocity sand erosion

Composite materials are used in the fan blades of advanced high bypass ratio aero-engines, and resistance to sand erosion is of significant importance for the design of these blades. This study investigates the sand erosion behavior of carbon fiber reinforced polymer (CFRP) composites under distinct impact velocities and erosion durations using rotary arm erosion testing apparatus. The damage evolution mechanism of CFRP laminates under sand erosion is quantitatively analyzed, while residual mechanical performance is also assessed. The experimental results show that continuous sand erosion typically results in erosion pits at the impact center and abrasion bands on the surface of CFRP laminates. It is found that as the erosion velocity increases, both the material strength and stiffness decrease significantly, with peak reductions of 64.7 % in tensile strength and 46.2 % in elastic modulus observed at the maximum tested velocity (200 m/s). An analytical model was developed to characterize the relationship between residual tensile strength and erosion damage parameters, which demonstrates good agreement with experimental results, with an average error below 7 %. The findings provide foundational experimental data on the erosion resistance and residual tensile properties of CFRP laminates, supporting the design and reliability assessment of erosion-resistant structures.