Experiment and Finite Element Characterization on the Compressive Creep Behavior of Glass‐Fiber Reinforced Polymer Composites

ABSTRACT Glass‐fiber reinforced polymer (GFRP) composites offer notable benefits, including exceptional mechanical performance, light weight, superior insulation, and corrosion resistance. The mechanical properties of GFRP are significantly influenced by their component materials and processing techniques. This paper presents experimental investigations combined with macroscopic and microscopic finite element analysis (FEA) of the off‐axis compressive creep behavior of unidirectional GFRP composites. Creep tests were conducted on 0°, 15°, 30°, and 90° GFRP lamina at seven distinct stress levels. The parameters of the unified creep strain prediction model (UCSPM) were calibrated. A macroscopic finite element model (FEM) of the GFRP lamina was developed, and a UMAT subroutine was used to characterize the off‐axis nonlinear and creep behavior. Additionally, a representative volume element (RVE) model was established based on homogenization theory. By calibrating the static and creep parameters of the component materials, the microscopic‐level static and creep behaviors of GFRP lamina were accurately predicted. The simulation results from both macroscopic and microscopic FEMs show strong agreement with theoretical predictions.