Time-Dependent Behavior of Single Pin–Bearing Connections in Pultruded Fiber-Reinforced Polymer Materials under Normal and Elevated Service Temperatures

This paper presents the results of an experimental investigation into the time-dependent behavior of an E-glass/polyester pultruded fiber-reinforced polymer (FRP) material subjected to single pin–bearing loads. The investigation involves experiments on single-bolt tension connections under a double-lap shear configuration at normal and elevated service temperatures. First, the effects of bolt-hole clearance and elevated temperature on short-term pin-bearing strength are evaluated. Next, time-dependent pin-bearing tests on material coupons are conducted at various load levels for time durations of up to 1,000 h. Based on the short-term and sustained load test results, a semiempirical predictive model is proposed for the time-dependent behavior of the pultruded FRP materials subjected to single pin–bearing loads. Finally, an equation is proposed to estimate the time-dependent pin-bearing strength of a connection that considers the effect of temperature and connection conditions.