Numerical analyses on thermal stress distribution induced from impact compression in 3D carbon fiber/epoxy braided composite materials

摘要

Thermal stress and thermomechanical coupling behaviors are essential to design 3D braided composite materials under impact loading. Here we report the thermal/mechanical coupling properties of 3D carbon fiber/epoxy matrix braided composite under impact compressions. The compressive behaviors of the 3D braided composites with different braiding angles have been tested. A high-speed camera system was used to capture the compressive deformation and damage developments. Two material models described as with thermal parameter (WT) model and without thermal parameter (NT) model were established to calculate thermal stress induced from impact compression. Both the two models give reasonable predictions. The plastic deformation energy of the composite is found to increase with braiding angle, resulting in higher temperature and greater thermal stress. The difference between the stress curves obtained from two models increases with the increase in braiding angle. Although the effect of thermal stress on the stress-strain curve obtained from two models is not obvious for the composite with smaller braided angle, the stress level of the resin and fiber tows of the WT model is higher than that of the NT model. The resin of the WT model has damages earlier and more serious. Likewise, the interface damage is also more serious.