Tensile mechanical behavior and failure mechanisms of fiber metal laminates under various temperature environments

This paper mainly investigates the tensile behavior of fiber metal laminates (FMLs) under various temperatures ranged from 25 degrees C to 175 degrees C combined experimental measurement, theoretical model and numerical technique. Firstly, based on numerous tensile tests under various temperatures, different tensile load-displacement response and damage modes for FMLs can be obtained and compared. And in virtue of the scanning electron microscopy (SEM), microscopic damage modes are identified through the fracture surface scanning of FMLs subjected to different temperatures. Subsequently, in order to analyze the discreteness of experimental results and evaluate the theoretical tensile strength of FMLs under different temperatures, the two-parameter Weibull statistics model is established for engineering application of FMLs. Finally, the effect of layer direction on damage modes and progressive damage evolution process of FMLs is characterized numerically. These results indicate that the tensile strength of FMLs represents a nonlinear downward trend with the increase of temperature. The complex failure mechanisms under different temperatures can be captured from SEM observation, including fiber/matrix debonding, fiber pull-out, matrix microcrack, delamination damage and so on. The deeper understanding of tensile behavior and failure mechanisms of FMLs under thermal conditions can be provided for the design and utilization of FML structures.