Predictive method for tensile response of glass fiber/ vinyl ester composites based on non-linear thermal response

Abstract

To explore the mechanical response of composites under fire conditions，a thermal-tensile response model for polymer composites considering matrix pyrolysis and fiber softening effects was developed. Nonlinear equations were solved using multidimensional array operations to research the variation of tensile performance of glass fiber/vinyl ester composites at high temperature and to predict the failure time under different tensile loads and one-sided heat flux conditions.The results indicate that the developed nonlinear thermal-tensile response model can effectively predict the tensile behaviour of vinyl ester and glass fiber/vinyl ester composites under unilateral steady heat flux. The results calculated using the model show that there are two distinct phases during the decrease of the tensile strength of glass fiber/vinyl ester composites with temperature decreasing： the first phase features a rapid decrease near the glass transition temperature，while the second phase shows a gradual decline following the complete glassy transition of the matrix. Furthermore，the failure time of the glass fiber/vinyl ester composites significantly decreases with increasing tensile load，displaying a consistent trend across different heat flux densities. Under constant tensile stress，the reduction in heat flux density can extend failure time of composites. Specifically，at the tensile stress of 80% of room temperature strength，the failure time of the laminate at 10 kW/m² is extended by 300 seconds compared to 75 kW/m2. Additionally，at 10 kW/m2，when the tensile stress is less than 50% of the room temperature strength，the laminate will not fail for a long time.

Keywords

• fiberglass/vinyl ester composites
• high temperature tensile properties
• failure time
• thermal response
• numerical calculation