ABSTRACT
With the advantage of easy construction and disassembly, the bolt connection is the most common form of pultruded GFRP profile connections. In coastal areas, long-termed exposure to the combination of high temperature and humidity leads to the degradation of mechanical property of FRP material. The moisture diffusion process plays a significant role in understanding the degradation of pultruded GFRP bolt connection in hygrothermal environments. In this paper, the non-Fick moisture diffusion process in pultruded GFRP bolt connection is numerically simulated. The moisture diffusion parameters were calibrated by gravimetric test of pultruded GFRP coupons. Parametric analysis is conducted to reveal the effect of temperature (40°C, 60°C, 80°C), solution type (fresh water and artificial sea water) and moisture absorption path in single-bolt connection. Besides, the moisture absorption of multi-bolt connection with different arrangements is compared. The results showed that the moisture absorption of specimen exposed to artificial sea water was obviously higher than specimen exposed to fresh water. For structures without damage, the moisture enters the panel mainly from surface; for structures with damage, the moisture from the open-hole plays an important role. The moisture diffusion behavior of specimens under 40°C environment was similar to specimens under 60°C environments. The moisture diffusion of specimen at 80°C was significantly more severe. By comparing multi-bolt connection with different arrangements, it was found that for structures with damage the moisture distribution was more concentrated near the open-hole in parallel bolt distribution than staggered bolt distribution.
