An investigation on impact behaviour of palm empty fruit bunch (EFB) composites fabricated using light resin transfer molding (LRTM) for bumper application

Abstract

This study investigates the possibility of replacing fillers for car bumper fascia with empty fruit bunch (EFB) originating from palm oils to be used as natural fiber-reinforced composites since EFB properties can still be explored and used for many applications. This research is focused on determining the mechanical properties of empty fruit bunch (EFB) composites based on material and manufacturing process parameters using light resin transfer molding (LRTM) through the design of experiment (DOE). Concentration was also given towards investigating the impact behavior of flat shaped empty fruit bunch (EFB) composites. Towards the end of the study, validation of impact behavior of flat shaped and curve shaped EFB composites was carried out from the construction and analysis of the finite element analysis (FEA) model. The study was done with parameter setup using the full factorial method under the design of experiment (DOE) to fabricate EFB composites via LRTM on A: LRTM resin pressure, B: EFB volume fraction and C: thickness of EFB. This setup was to obtain ultimate strength and Young’s modulus for the mechanical properties of the EFB composite. After gaining the optimum configuration for EFB composite—i.e., 1 bar LRTM resin pressure, 0.10 volume fraction and 6 mm for the thickness; ultimate strength, 39.26 MPa and Young’s modulus, 4.55 GPa, the study advanced to observe the EFB composite impact behavior to be compare was the simulation result. For the simulation via LS-Dyna, five types of mesh sizes 0.5 mm, 1.0 mm, 1.5 mm, 2.0 mm, and 2.5 mm, were evaluated. After the evaluation, the 0.5 mm mesh size had good agreement with the experimental result and completed within reasonable computational time. The model with 0.5 mm mesh size was used to develop the curve shape of the car bumper fascia. This study was also done with parameter setup using the Taguchi method under the design of experiment (DOE) to create a curve model via LS-Dyna on A: radius curve shape, B: width curve shape, and C: thickness curve shape. This setup was to obtain the peak force and energy absorption for the car bumper fascia. The optimum configuration obtained were 300 mm radius curve shape, 200 mm width curve shape, and 20 mm thickness curve shape, with peak force of 5.58 N and energy absorption of 4.89 J from the Taguchi method. The result for ultimate strength and Young’s modulus were significant as it was similar to the current work that used the same EFB composite material. Likewise, the impact behavior result was also significant as the experimental result has good agreement with the simulation. From the fabrication and impact behavior result, the studied EFB composite can be implemented in car bumper applications.