A study on mechanical behavior of the carbon fiber composite sandwich panel with pyramidal truss cores at different temperatures

A series of compression tests were conducted to investigate the mechanical properties and failure mechanisms of carbon fiber composite sandwich panels using pyramidal truss cores subjected to temperatures ranging from 100℃ to 350℃.The compressive strength and stiffness of sandwich panels decreased as temperature increased.Cryogenic temperatures caused an increase in strength and stiffness,while elevated temperatures resulted in a reduction of strength and stiffness.The effect of temperature on the failure mode of the sandwich panel was revealed as well.The interface between the fiber and matrix was examined by a scanning electron microscope(SEM) in order to study the effect of temperature on strengthening the mechanism and good bonding conditions within the fiber-matrix interface was observed at cryogenic temperatures.The comparison of the predicted and experimental data indicated that the stiffness and strength of the composite sandwich panels for temperature variation was consistent.