Experimental studies of the high temperature influence on strength and deformation properties of combined glass organoplastics

The investigation of high and low temperature influence on the mechanical properties and failure mechanisms of composite materials is an important problem, as well as the determination of the temperature dependence between elastic and strength characteristics for fiber composites which are used in critical structures. The study is focuses on combined composite materials which are based on a combined glass organofabrics with two types of matrixes (epoxy, polyimide). The aim of the present study has been to investigate the degradation of mechanical characteristics of composite materials at higher temperatures. The research has been carried out using a universal electromechanical system Instron 5882 which includes a thermal chamber and non-contact video extensometer. The high temperature studies at 500 °C have been conducted using the servo hydraulic test system Instron 8850 with a high temperature chamber. The paper presents the results of the experimental studies related to the high temperature influence on the mechanical properties of composites based on glass organofabrics with two types of matrixes (epoxy, polyimide) under tension and bearing. Mechanical tensile and bearing tests at normal and high (100 °C, 250 °C and 500 °C) temperatures were carried out. The postcritical deformation stage has been determined. The mechanical properties (elastic modulus, strength limit and bearing strength) of the composites have been found. The stress-strain diagrams for composite specimens have been built. The temperature degradation of mechanical properties for composites has been analyzed.