Kekuatan Bending Komposit Sandwich Serat Gelas Dengan Core Divinycell-PVC H-60 (Pengaruh Orientasi Serat, Jumlah Laminat Dan Tebal Core Terhadap Kekuatan Bending)

Abstract

Abstract : This study aims to investigate the effect of fiber orientation to bending strength of GFRP (Glass Fiber Reinforced Plastic) composite and the effect of laminates number and core thickness to bending properties of GFRP sandwich composite with divinycell-PVC core type H-60. The composites were produced by using a press mold method for 40% of fiber volume fraction (vf). The GFRP composite specimen consists of 4 laminates – woven roving glass fiber, varied by fiber orientation as [(0/90)4], ([((30/-60)/(60/-30))2], [{(45/-45)4}], [{(30/-60)/(0/90)}2], and [{(45/-45)/(0/90)}2]). The GFRP composite whose the highest bending strength was used as skin of the sandwich composite. The variables of the sandwich are laminates number (2L, 4L, 6L, 8L) and core thickness (5, 10, 15, 20 mm). According to ASTM D- 790 and ASTM C-393, the GFRP and sandwich composite specimens were tested by using three point bending method. The result shows that the GFRPcomposite, reinforced by [(0/90)4] of fiber orientation, has the highest bending strength (226.62 MPa) compared to others, and it’s failure is dominated by interlaminate delamination. For GFRP sandwich composite with 10 mm of core thickness, the maximum moment capacity increases a long with the increasing of laminates number. However, the highest bending strength is achieved on the sandwich composite with 4 laminates of glass fiber. All specimens shows core shear failure model. And then, for sandwich composite with skin 4 laminates, the increasing of core thickness also increases moment capacity consistenly, but it decreases the bending strength significantly. Similarly, the decreasing of core shear strength also happens on the specimen. On the specimen occours core shear and indentation of failure types.

Keywords : Bending strength, GFRP, Sandwich composite, Divinycell-PVC core