Creep analysis of E‐glass/vinyl‐ester laminated composites for underground vault structures

Abstract Creep is eminent in fiber reinforced polymer matrix composite materials given the susceptibility of polymers to constant loading. The response of polymer matrix composites used in retrofitting vital infrastructure to long‐term flexural loadings is investigated to elucidate the effect of creep. The experimental approach consisted of first establishing a benchmark of the quasi‐statically tested flexural properties. A fresh set of samples were then flexural tested for an extended period. Failure was determined to be strain‐driven in both quasi‐static and long‐term testing conditions. The mechanical properties were found to be insensitive to the strain rate (in the low strain regime), while being mildly sensitive to creep loading. The flexural response also showed dependence on the historic creep loading. The creep strain was successfully fitted into Baily‐Norton power law, which allowed for forecasting the creep life based on the critical strain failure criteria. The overall results explicate the interrelation between long‐term loading and fidelity of composites‐based infrastructures.