ASSESSMENT OF THE DEFORMATION HEAT RESISTANCE OF FIBERGLASS SAMPLES OF COMPOSITE STRUCTURES

The article presents the results of a study assessing the deformation heat resistance of unidirectionally reinforced fiberglass samples taking into account increased bending stress. Due to their high performance and mechanical properties, polymer composites are widely used in the manufacture of critical structures. Deformation heat resistance determines the reliability and safety of polymer composite structures. Based on the Martens method, a method for assessing the deformation heat resistance of composite samples with continuous reinforcement at increased bending stress of the sample is proposed. Based on the test results, thermomechanical curves were constructed and the deformation heat resistance of fiberglass samples with unidirectional continuous reinforcement was assessed at increased bending stresses of 5, 20, 35, 50, 65 MPa. Tests of fiberglass samples were carried out in the temperature range 20÷200 °C. Based on the inflections on the thermomechanical curves, the valuesof the deformation heat resistance of unidirectionally reinforced fiberglass samples in the range of 160÷120 °C were determined. Polynomial dependences of deformation on temperature at various bending stresses of unidirectionally reinforced fiberglass samples were obtained. It is shown that the permissible deformation heat resistance of a polymer composite structure must be determined taking into account the stresses acting in it.