Indra Sidharta

The Effect of Hollow Glass Reinforced Epoxy in Absorbing Impact Energy for Vehicle Bumper Application

Safety is one of important factors which has to be considered in designing automobile in the automotive industry. One of the components related to the automobile safety is bumper. Bumpers are attached on front and rear of vehicle’s body in order to protect the body from damage due to low speed crash. In this research, hollow glass microsphere (HGM) reinforced epoxy is used as the material for the bumper since this material has not been applied to this application yet. This research is conducted in order to find the ability of this composite material in absorbing impact energy from low speed crash by using finite element method. Thickness of the bumper varied from 4 mm to 8 mm with 1 mm increment. Low speed collision is simulated by following Economic Commission for Europe Regulation 42. The bumper energy absorption is analyzed and indicated by the internal energy, deformation, and equivalent stress from each bumper’s thickness.

Water resistance performance test of GESITS electric scooter

GESITS is an Indonesia electric scooter with design and manufacture in Institute of Technology Sepuluh Nopember (ITS) Surabaya, Indonesia. It is the first electric scooter in Indonesia that developed by a group of Indonesian engineers and business people that banded together to deliver the product to the market. One of the key to the successful implementation of e-scooter is the water resistance performance test of the e-scooter. In order to accomplish the protection, it is important to conduct the water ingress test based on Standard IPX5. In this paper explains the water resistance performance test for GESITS and then discuss some results. In accordance with the test procedure to evaluate IPX5 protection against ingress of water, the water resistance shall be carried out by spraying with a stream of fresh water the enclosure from all practicable directions with a standard test nozzle. The results showed that after finished the test and analyzing both the battery compartment and the controller compartmen...

Thickness Effect of Polyurethane Foam Core on the Flexural Behaviour of Composite Sandwich Materials

This study explored the feasibility of flexural performance of composite sandwich material composed of various low density polyurethane foam core thickness sandwiched between GFRP skins. The mechanical behaviour of this material was assessed by carrying out a flexural testing. Each spesimen had a nominal dimensions of 110 mm x 30 mm x (c + 4 mm). These spesimens with various core thickness (c) of 2 mm. 5 mm. and 8 mm were then tested in three point bending according to ASTM C 393-00. This study revealed that. by incorporating the thickest core ( 8 mm ) . the bending strength decreases by 42.3 % compared to 5 mm core and it further decreases by 72.6 % compared to 2 mm core. The material stiffness showed positive trend for the thickest core (8 mm). it increases by 53.1 % and 78.1 % compared to 5 mm core and 2 mm core respectively. Low shear modulus of polyurethane foam core contributed to the low bending strength of composite sandwich material with 8 mm core. This was further confirmed by failure analysis under optical microscope which revealed that core shear failure was the dominant failure mechanism for 8 mm core. Meanwhile the dominant failure mechanism for 2 mm core and 5 mm core was microbuckling which confirm the high modulus of GFRP skin. The material stiffness was affected by the high modulus of GFRP skin and the core thickness.