Comparison Behavior of Tensile Tests for GFRP Filament Wound Pipes With Two Different Sectional Areas Regarding High Temperature

Abstract

In this work were compared two types of filament wound pipe specimens to know the variation in stress and strain regarding to the cross sectional area variation at 65° C according to the standards. The groups are named as G1 and G2, respectively with the G1 having 63.5mm of internal nominal diameter, and the G2 having 76.2mm. Both groups had 800mm of length, 3.5 mm of wall thickness and tabs laminated with 200 mm length. It was applied a monotonic load with a rate of 6.35 mm/minute. Three strain gages were positioned circumferentially and other three axially oriented at the specimen middle span. The high temperature was controlled by thermo pairs and the thermal box was heated up to reach the test temperature. So the tests were carried out up to failure of the specimens. The results showed that the sectional area may affect the strain at higher temperatures above of 50 °C. It was also noted variations between both groups regarding their strength capacity, mainly at the serviceable limit state of loading, which was determined by the first lost of loading followed by any kind of possible damage — matrix cracking, delaminating or fiber fracture. It could be noted that for high pressure and severe conditions use, the serviceable limit state is the most appropriated level that one should consider when designing glass fiber reinforced polymer to use in pipelines and others offshore structures subjected to internal and external loading pressures.