The honeycomb sandwich structure has been extensively investigated for its mechanical performance. Modification in improving such mechanical properties is an innovation required for honeycomb sandwiches, especially by adding a random fibers reinforcement inside a sheet panel plate. This study was developed random fiber reinforcement using natural fiber of Oil Palm, Sugar Cane, and Coconut, which constructed by the commercial software code of MATLAB. This investigation analyzed the performance of three-point bending behavior using the finite-element model, which provides four levels of fiber condition to observed: 0, 50, 100, and 150 fiber numbers. Ansys Workbench/Dynamic code was chosen to predict mechanical performance such as stress and displacement analysis. In the fiber development study, a series of numerical simulations were carried out with two types of fiber orientation reinforcement, unidirectional and chopped randomly. The hybrid orientation was also implemented in this research by combining unidirectional and chopped fiber, which was fixed at 150 numbers and then varied in three sets: S50/C100, S100:C50, and S75/C75. As a result, it was confirmed that the fiber reinforcement enhances the stiffness of the structure, which contributed a lot to the promotion of the bending resistance capacity and energy absorption. Especially, unidirectional fiber orientation has shown a significant increase in absorbing stress during testing. The fiber reinforcement sandwich demonstrated better mechanical behavior in the simulation, as reported by the hybrid system, and this was influenced by the unidirectional orientation.

Unstable wind speed in Malaysia has been a problem for the wind turbine. Vertical axis wind turbine (VAWT) that is placed on the ground causes unnecessary stress and hinder it to perform at maximum performance. Thus, the purpose of this study was to analyze the behavior of VAWT at different wind speed. The conceptual design was generated by using the pugh method. Then the structure of the blade was analyzed in terms of displacement and von Mises stress, followed by topology optimization. Results show that peak stress for both forces applied and pressure applied was located at the center where maximum displacement is about 5.43x10-6m while the maximum value of von Mises stress is about 0.9763Mpa at the edge of the blade and 0.6641MPa when pressure is distributed uniformly. Based on topology optimization, the blade area can still be reduced at the top and bottom part.