High temperature indentation behaviors of carbon fiber composite pyramidal truss structures

The composite sandwich panels with pyramidal truss cores were fabricated by the hot-press method. Subsequently, the experimental studies were performed to investigate the quasi-static indentation response of composite sandwich panel at high temperature. The quasi-static indentation tests of composite sandwich panels were conducted at temperatures ranging from 20 °C to 200 °C. The damage mechanism, load-displacement curves, indentation load and absorbed energies at high temperature were investigated and compared with that at room temperature. The results showed that high temperature induced a change in the failure mechanism and had the significant effect on the load-displacement curves, indentation load and energy absorption. The indentation load and absorbed energies decreased as temperature increased. Especially at 200 °C, the reduction in indentation load and absorbed energies was more severe, which was are mainly due to the degradation of matrix properties and fiber-matrix interface properties at higher temperature.