International Journal of Innovative Research in Advanced Engineering (IJIRAE) ISSN: 2349-2163 Issue 04, Volume 4 (April 2017) (SPECIAL ISSUE) www.ijirae.com ______________________________________________________________________________________________________ IJIRAE: Impact Factor Value – SJIF: Innospace, Morocco (2016): 3.916 | PIF: 2.469 | Jour Info: 4.085 | ISRAJIF (2016): 3.715 | Indexcopernicus: (ICV 2015): 47.91 IJIRAE © 2014- 17, All Rights Reserved Page -103 Review on Behaviour of FRP composites subjected to Elevated Temperatures Dr. Venkatesh M K #1 , Praveen H Y *2 #1 Associate Professor, *2 Student, 4 th Semester M.Tech (CIM) Department of Mechanical Engineering, Dayananda Sagar College of Engineering, Bangaluru, India Abstract — FRP bars are increasingly used in many industries viz construction, automobile, electrical and defence to name few [1]. Mechanical strength, durability and stability are the few important parameters to select the FRP bars produced through Pultrusion process [3]. When these FRP bars are exposed to high temperatures, the change in the material properties affects the overall structural performance. FRP’s are the best choice for corrosion resistance requirements. In this paper, the investigators [2] tested GFRP (Glass fiber reinforced polymers) to check the tensile properties at high temperature. Specimens were exposed to high temperatures and tested for tensile strength. It is observed that there is a strong effect of heat on tensile strength and Young’s modulus. In specific ultimate strength shows a constant degradation as temperature increases. By contrast, the Young’s modulus is subject to different changes at different temperatures. Keywords— pultrusion, FRP, mechanical strength I. INTRODUCTION Polymer matrix composites (PMC) have established themselves as engineering structural materials, not just as laboratory curiosities or cheap stuff for making chairs and tables. Glass fiber reinforced polymers and Carbon fiber reinforced polymers represents the largest class of PMC. The pultrusion process is continuous and therefore the costs reduce with respect to other methods of fabrication, especially when high volumes of production are reached. Generally the profiles and rods are made from polyester, epoxy or vinyl ester resin as matrices, with glass, carbon or aramid fibres as reinforcements. It is not easy to set up a procedure to evaluate temperature resistance because of the many aspects to be taken into account and of the different types of physical and chemical changes provoked by different exposure to heat. This paper presents a procedure to expose FRP rods made from a polyester resin matrix and glass fibers, to elevated temperatures in a tubular oven with controlled air flow. II. PULTRUSION PROCESS Pultrusion is a composite fabrication process designed for structural shapes. The investment cost is very high and therefore only feasible for mass production parts. Fibers are drawn through a resin bath and then through a forming block. Heaters are used to insure fast curing through steel dies and then the part is cut to proper length. Pultruded parts are strongest in the longitudinal direction because of their fiber orientation. Fiber orientation can be changed to increase strength in other directions. Solid, open sided and hollow shapes can be produced at almost any length. Cores such as foam and wood can be built inside of the pultruded shapes. Due to the pressure and designs of production, protruded production can be up to 95% effective in material utilization [8]. The schematic of pultrusion process is shown in figure 1. Figure1: pultrusion process