PSI - Issue 27

Angga Kengkongan Ary et al. / Procedia Structural Integrity 27 (2020) 69–76 Ary et al. / Structural Integrity Procedia 00 (2019) 000 – 000

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chassis, which is successfully mass-produced. Even Lamborghini in the Murcielago series no longer applies metal material as its constituent material, but it uses carbon fiber (Wang et al., 2018). Compared to previous works, this paper analyses several parameters of the chassis based on the material type, the thickness of the material, and the given load. As a geometrical model, an alternative frame, which is inspired by vehicles used at the Indonesian energy efficient car contest to be numerically modeled, and then finite element analysis conducted to acquire an estimation of structural performance under selected parameters. 3. Design and simulation according to KMHE regulations An alternative urban vehicle is a type of vehicle which is designed and constructed by college students to participate in KMHE (energy-efficient car contest). It is a national energy-efficient car contest held by the Ministry of Research, Technology, and Higher Education of the Republic of Indonesia annually where the winner is the one that can travel the longest distance with the least amount of fuel consumption. This contest aims to find innovative ideas to create vehicles that the world needs, energy-efficient cars. There are two categories in this competition; it is a prototype and an urban concept. The urban concept category is a fuel-efficient vehicle that looks like a passenger car today. Urban concept vehicles must meet special regulations set by the KMHE committee. The overall height of it should be between 100 – 130 cm, the width between 120-130 cm, a total length between 220 and 350 cm, track width at least 100 cm for the front wheel, and 80 cm for the rear wheel, and the wheelbase at least 120 cm. All regulations for the vehicle are stated in KMHE technical regulation 2019 (Mat et al., 2012). These regulations are the guidelines for designing the chassis used in this research. The chassis design of the participating vehicle in the competition choose since the prospect is up-and-coming, which has high potential in terms of concept implementation on the widely used urban cars. Therefore, it is quite relevant to take this chassis as a research subject in which the data results projected to use as the consideration of future vehicle chassis production. Although the goal of the vehicle competition discussed before is fuel efficiency, the chassis must still be stiff enough for excellent handling and has sufficient strength to support all working/applied loads (Guron, 2012). The frame must be able to accommodate its engine and driver. The regulation state that the driver should have a minimum weight of 70 kg (Mat et al., 2012), and the engine is assumed approximately 15 kg. The ladder frame, which rectangular hollow profiles welded to form this chassis geometry, is selected as the chassis type considering its simplicity, lightweight, and ease of construction (Ghalazy, 2014). In the current research, alternative urban vehicle chassis investigated by composing a series of technical scenarios. The first part designed to involve two material types, i.e., aluminum 6061 and carbon-fiber reinforced plastic. The second part considers the material thickness, which applies to the chassis with values 1.4 mm and 0.9 mm. The current frame used by the team has 1.2 mm of thickness, so the 1.4 mm and 0.9 mm of thickness choose as a comparison to the existing chassis. The third part is the applied loads, which assume the engine and driver as the main contributors. Variation of the 2-load design considered, engine only and driver only. The designed research scenario summarised in Table 1. The investigation performed to obtain the safety factor, stress, displacement, and strain. Autodesk Fusion 360 selected as an instrument for modeling and simulation in this work which technical methodology presented as follows:  3D model of chassis assembly idealized using Autodesk Fusion 360  The thickness of the model is adjusted then the material type is applied  Static analysis is performed on chassis assembly with load variation to estimate the physical influence of the parameter mentioned to the chassis using Autodesk Fusion 360 The vehicle chassis designed with rectangular hollow sections. The section has a 1x2 in dimension with thickness variation. After the design stage, the mesh criteria (shown in Table 2) are used for the meshing technique to the chassis then applied two different loading conditions, i.e., static load (dead load) of the engine (15 kg) and driver (70 kg) as stated in regulation for minimum driver weight). As for the dead load analysis, the loads specified at specific points on the chassis. The value of the assumed loads is 150 N, and 700 N with assumption 1 N equals 0.1 kg. After the load applied, then the structural constraint is determined. In this research, all four shafts of the vehicle fixed as the structural constraint for supporting the load given to the vehicle. The load condition and restrictions are shown in Fig. 1.