Effect of Fibers Configuration and Thickness on Tensile Behavior of GFRP Laminates Exposed to Harsh Environment.

Bazli Bazli,Ashrafi Ashrafi,Zhao Zhao,Bai Bai,Jafari Jafari,Raman Raman

doi:10.3390/polym11091401

Abstract

The present study indicates the importance of using glass fiber reinforced polymer (GFRP) laminates with appropriate thickness and fibers orientation when exposed to harsh environmental conditions. The effect of different environmental conditions on tensile properties of different GFRP laminates is investigated. Laminates were exposed to three environmental conditions: (1) Freeze/thaw cycles without the presence of moisture, (2) freeze/thaw cycles with the presence of moisture and (3) UV radiation and water vapor condensation cycles. The effect of fiber configuration and laminate thickness were investigated by considering three types of fiber arrangement: (1) Continuous unidirectional, (2) continuous woven and (3) chopped strand mat and two thicknesses (2 and 5 mm). Microstructure and tensile properties of the laminates after exposure to different periods of conditioning (0, 750, 1250 and 2000 h) were studied using SEM and tensile tests. Statistical analyses were used to quantify the obtained results and propose prediction models. The results showed that the condition comprising UV radiation and moisture condition was the most aggressive, while dry freeze/thaw environment was the least. Furthermore, the laminates with chopped strand mat and continuous unidirectional fibers respectively experienced the highest and the lowest reductions properties in all environmental conditions. The maximum reductions in tensile strength for chopped strand mat laminates were about 7%, 32%, and 42% in the dry freeze/thaw, wet freeze/thaw and UV with moisture environments, respectively. The corresponding decreases in the tensile strength for unidirectional laminates were negligible, 17% and 23%, whereas those for the woven laminates were and 7%, 24%, and 34%.

Highlights

Use of fiber-reinforced polymer (FRP) composites is rapidly increasing in automotive, aerospace, and marine applications, as well as in civil engineering [1,2,3]
The present study, as part of an ongoing research project on the durability of FRP composites used for structural applications, focuses on the tensile properties of glass fiber reinforced polymer (GFRP) laminates subjected to regular harsh environmental conditions
To investigate the degradation mechanism of GFRP composites, the surfaces of selected laminate samples before and after exposure to different environmental conditions were observed under scanning electron microscopy (SEM)

Summary

Introduction

Use of fiber-reinforced polymer (FRP) composites is rapidly increasing in automotive, aerospace, and marine applications, as well as in civil engineering [1,2,3]. These composites have several advantages, including lightness, high strength, ease of installation and handling, corrosion resistance, and relatively good durability properties, which have made them an attractive alternative to traditional materials (i.e., steel) in many applications [4,5,6]. Relatively fewer studies have focused on the performance of FRPs subjected to the harsh environmental conditions posed by the freeze/thaw cycles that simulate cold region climates or by the UV, moisture, and elevated temperature conditions that simulate sunny days in hot regions [12,45,46,47,48]

Methods

Results

Conclusion