Numerical analysis of punch shear failure and stress characteristics of three-dimensional braided composite with different braiding angles

This paper presents a multi-scale finite element model to calculate the stress field and analyze the punch shear failure of three-dimensional braided composite at high strain rates. The multi-scale model was established based on real braided structure taking the surface and corner braiding yarns into consideration. Constitutive material modeling and failure criterions were introduced into the model. Three braiding angles of 25 degrees, 35 degrees, and 45 degrees were applied to reveal the relations between failure states and braided structure. The results showed that the punch shear failure states and stress distribution were greatly dependent on the strain rates and braiding angles. Nonuniform stress propagation resulted in shear bands and different formation paths were observed on the composite with different braiding angles. The ultimate failure of braided composite was determined by comprehensive action of compressive and tensile stress. In addition, the progressive damage of typical braiding yarns in different conditions was obtained from the modeling simulation. The three-dimensional braided composites with different braiding angles showed unique failure morphology. It was closely determined by the complex braided structures.