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°C to 350°C. 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.