Selection and analysis of optimum stacking sequence and geometry dimensions on bismaleimides composite joints under tensile loading

This paper presents experimental and numerical investigations in the single-lap, single-bolt joints of carbon fiber reinforced bismaleimides (CF/BMI) composites. In order to guide the engineering design, an optimum configuration of composite joints is determined. Effects of stacking sequence and geometry dimensions on composite joints under tensile loading are discussed to select an optimum configuration. The optimum configuration is validated by the experimental method. Quasi-static tensile tests are conducted according to ASTM D5961 to evaluate the joint stiffness, joint strength, and bearing behavior. Finite element (FE) models considering progressive failure and delamination failure are established to investigate the joint stiffness, bearing strength, damage mechanisms, and evolution of delamination damage. Results show that bearing failure accompanied with delamination caused by secondary bending is the main failure mode, indicating an expected non-catastrophic failure mode.