Komposit Sandwich Berpenguat Hybrid Serat Bambu Ori Dan Serat Rami Pada Skin Dan Berpenguat Serbuk Kayu Sengon Laut Dan Serbuk Tempurung Kelapa Pada Core Dan Bermatrik Polyester
The purpose of the research is to determine the influence of core thickness variation and variation of fraction to increase bending strenght and impact of hybrid composite sandwich combination of hemp fiber and bamboo fiber with combination of core of sengon laut wood powder and coconut shell powder. The fracture mechanism is observed with macro photos. The main material of this research is sengon laut wood powder with 20 mesh and coconut powder powder with 4 mesh, hemp fiber (woven), ori bamboo fiber (random), unsaturated polyester resin 157 BQTN. The hardener used was MEKPO with a concentration of 1%. Composites are made by press molding method. The volume fraction amplifier () core is 5%, 10%, 20%, 30% and 40%, while the volume fraction amplifier () skin is 40%. For the thickness of the core is 5 mm, 10 mm, 15 mm and 20 mm, while the skin thickness is 5 mm. Specimens and procedures for bending and impact testing refer to the ASTM C 393-00 and ASTM D 6110 standards. The cross section of the fracture is carried out in a macro photo to identify the pattern of failure. The results of this study indicate that the ability to withstand bending moments and the impact strength of hybrid sandwich composites increases with increasing volume and thickness fractions on the core. The strength of the bending hybrid composite sandwich moment has the most optimum price at powder volume fraction () 40 % with core 20 mm thickness ie 147669,23 N.mm. The optimum impact strength in the volume volume fraction () is 40% with a core thickness of 20 mm which is 0,05640 J / mm². The stages of failure pattern of hybrid sandwich composites are skin press failure, core shear failure and skin lamination with cores.
