Investigation of the Influence of Heat Treatment on the Strength of Sandwich Structures

Abstract

The article presents the data of an experimental study on how heat treatment influences the physical and mechanical properties of cured samples of sandwich structures. The sandwich structures were made using VaRTM method. Heat treatment at 80 °С and 60 °С leads to increase in the tensile strength. Three-point bend tests were conducted. The results characterize the relationship between the durability and the temperature and exposure time of the sandwich structures. The results correlate with the data of structural studies of fracture cross-sections and research on the extent of swelling of the cured binder. The SEM micrographs of the microstrustructures of fiberglass reinforced plastic samples show that during heat treatment there is a structural refinement of the polymer matrix. As a result of heat treatment at 80 °С for 4 hours, the extent of swelling decreased by 14%. The heat treatment of sandwich structures at a temperature of 80 °С for 4 hours is optimal and leads to increase in the tensile strength by 30.7%.