Characteristics of the carbon - E-glass 185 WR reinforcement polyester hybrid composite with an open hole

Abstract

Glass or carbon fiber are widely used in polymer composite, cause of their lightweight and reasonable strength. Even the combination of these fiber as reinforcement in polymer composite was also being reported in scientific report. But, there is no report of the hole effect toward mechanicals aspect of dual fiber composite. Hole was formed when mechanical fastening applied in composite. In this study, E-glass WR 185 and woven fabric carbon fiber used as a reinforcement (40% weight) in polyester BQIN EX 157 matrix. Fiber arrangement is carbon - E-glass – carbon, in total of 5 carbon fibers and 4 E-glass fibers. The composite made by hand lay-up methods; in which all fibers were laminated one by one layer with polyester resin. Completely dried up was attained after 48 hours. Then composite was mechanical cut off to make specimens. The density test specimen has area of 10x10 mm2. Tensile test specimen has total length of 250 mm and width of 25 mm, refer to ASTM D3039. Specimen for compression test has length of 140 mm and width of 13 mm, refer to ASTM D6641. And shear test specimen was made according to ASTM D5379. Some of tensile and compression specimens were drilled at the center, here in marked as “open hole”. The result showed that combining carbon and E-glass fiber as reinforcement in polyester composite resulted a bit weightier composite of 1.42 g/cm3, but much stronger composite than the E-glass fiber reinforced composite. The remarkable mechanical strength of composite are 293 MPa of tensile strength, 147 MPa of compressive strength, and 44 MPa of shear strength. The composite has a relatively high shear strength with a low tolerance to plastic deformation. Introducing an open hole had reduced tensile strength to 237 MPa, and compressive strength to 139 MPa. Meanwhile two tensile specimens were broken with mode of angle gage middle (AGM) while other five specimens experienced angle gage top (AGT). Compressive test specimens dominated with angle gage middle (AGM) failure mode. Introducing open hole enables a low stress failure mode (LGM) both in tensile and compressive test.