Rancang Bangun Alat Pencekam pada Universal Testing Machine untuk Pengujian Geser Material Komposit

Abstract

Shear testing is conducted to examine the shear strength of a material both metal and composite materials by measuring the maximum shear stress that can be held by the material before fracture. The purpose of this research is to build a composite specimen gripping tool, namely a jig and fixture in the testing machine, namely a Universal Testing Machine (UTM). This research was conducted by modifying the Jig and fixture according to the characteristics of the composite material, then fabricating and testing using composite material specimens. The jigs and fixture is built from Steel ST42 material through milling and lathe processes. The components of the jig and fixture consist of a fixed grip, moving grip, adjustable jaw, base plate, rail, shaft support, and shaft. The dimensions of the tool are 157 mm in length, 70 mm in width, and 160 mm in height. This tool is mounted on a UTM and tested using composite materials that are driven by hydraulic power. The composite materials are made from glass fiber and polyester resin according to ASTM D5379-98 standard. The dimensions of the specimen are 76mm × 20mm × 12mm and there is a 90 0 V-notch in the middle side with 4 mm depth. The test result showed the average shear strength value is not much different from 35.42 Mpa/mm 2 with a 95% confidence level. The jig and fixture are in accordance with the UTM and after being tested there are no disfunctions so it is feasible to use.