Research on low‐velocity impact damage of composites based on improved Chang–Chang criterion.

Considering the nonlinearity of shear in the mechanics of composite materials, the increase of shear strength when the substrate interface is compressed, and the shear of the matrix itself, the Chang–Chang criterion is improved. The improved Chang–Chang criterion was used to establish a progressive damage model of low‐velocity impact of composites. The low‐velocity impact process of T700/EM134 composite laminates in the energy range from 5 to 10 J was compared by physical tests and finite element simulations, and the calculated impact response curves and material damage were in good agreement with the test results, which proved that the model of the improved criterion was suitable for the damage prediction of low‐velocity impact of composite laminates. Highlight: Consider various situations in composite material shearing.Improved based on the Chang–Chang criterion.Establishing a progressive damage model for low‐speed impacts.Comparison through physical experiments and finite element simulation.Prove that the improved criterion model is suitable for damage prediction. [ABSTRACT FROM AUTHOR]