Simulation of Static Loading of Electric Tricycle Frame

Electric vehicles are growing to replace petroleum-fuelled vehicles because of environmentally friendly. The manufacture of electric tricycle must consider the planning of frame construction that is able to support all loads such as passenger loads, engines and other equipment components. Therefore, it must be ensured that the strength of the frame is able to withstand static loads. In this study, a simulation of static load on the frame of an electric tricycle was carried out by varying the size and thickness of the frame pro-file. The frame used is a hollow square with a size of 40x40 with a thickness of 0.8mm, 1.0mm and 1.2mm and a size of 40x60 with a thickness of 1 mm. This study uses Fusion 360 software to simulate static loading with a load of 500 Kg. The recommended safety factor is 3.5. So, based on the simulation results, the eligible frames are hollow steel 40 x 40 with a thickness of 1 mm and hollow steel 40x60 with a thickness of 1 mm. Both of these materials have the same frame weight. Both of these materials have almost the same Von Misses stress, it is 51.34 MPa and 50.37 MPa respectively. The 40 x40 hollow steel has a larger displacement of 0.84 mm while 40x60 hollow steel with a thickness of 1 mm only has a displacement of 0.44 mm. Therefore, 40x60 hollow steel with a thickness of 1 mm is more recommended to be used as a frame for this electric tricycle.


Introduction
Electric vehicles continue to be developed to replace vehicles with fuel from petroleum.An electric vehicle is a vehicle that moves with one or more electric motors, from electrical energy stored in rechargeable batteries or other energy storage devices.Electric vehicles have the advantage of being more environmentally friendly than petroleum-fuel vehicles that cause pollution.In addition, fossil fuels are also increasingly limited so it is necessary to look for alternative renewable energy [1,2].
The design of electric vehicles is very dependent on the needs of urban communities who need vehicles that are efficient, few passengers and small so that they are free from traffic jams.The development of batteries that are still limited also limits the range of electric vehicles.Currently, electric tricycle are developing which are in great demand by the public because they are smaller and light weight than cars.
The manufacture of electric tricycle must consider the planning of frame construction that is able to support all loads on the vehicle such as passenger loads, engines and other equipment components.Therefore, it must be ensured that the strength of the frame is able to withstand the load which is usually a static load on the vehicle.The load of an electric car in the form of passenger weight, engine weight, and the weight of other components is placed on the frame [3,4,5].A strong construction to withstand the load of an electric car is the main character of a frame.The weight and strength of the frame are often considered in the selection of a frame material.The choice of a lightweight frame material will affect the low energy consumption but must ensure the safety of the vehicle.Material selection, deflection value, voltage, and safety factor are the main parameters to determine the strength of an electric car frame [7,8].
The purpose of this study was to simulate the static load on the electric tricycle frame by varying the size and thickness of the profile to obtain optimal frame strength with minimum weight.

Methods
This research is using Autodesk Fusion 360 software (Student license) to create designs and perform simulations, starting from creating a mesh, entering the required parameters, and finally doing the Finite Element Analysis (FEA) simulation process.The static load on the vehicle frame is 500 kg.The profiles used are hollow squares with a size of 40x40 with a thickness of 0.8mm, 1.0mm and 1.2mm and a hollow square with a size of 40x60 with a thickness of 1.0 mm.The design of the electric rickshaw frame analyzed is as shown in Figure 1.

Figure 1. Frame design of electric tricycle
The frame material used is medium carbon steel with the properties listed in table 1.The simulation results analyzed are safety factor, von mises stress and displacement.

Result and Discussion
After simulating static loading on the frame of an electric tricycle using a hollow square with a size of 40x40 with a thickness of 0.8mm, 1.0mm and 1.2mm and a hollow square with a size of 40x60 with a thickness of 1.0 mm, the simulation results are shown in table 2. The simulation results analyzed are safety.factor, von misses stress and displacement.The recommended minimum safety factor is 3.5.So based on the simulation results, the frame with 40 x 40 hollow steel with a thickness of 0.8 mm and a thickness of 1.0 mm does not meet the requirements because it only has a safety factor of 2.487 and 3.201, respectively.The frame that meets the requirements is a hollow steel frame of 40 x 40 with a thickness of 1.2 mm which has a safety factor of 4.032 and a hollow steel 4x6 thickness of 1 mm with a safety factor of 4.11.Both of these materials have the same frame weight.

Von Mises stress analysis
The comparison of the maximum von Mises stress between the four types of materials can be seen in Figure 2. The highest maximum von Mises stress is on a 40 x 40 hollow steel frame with a thickness of 0.8 mm which is 83.22 MPa while the lowest maximum von Mises stress is on 40 x 60 steel. 1 mm thick is 50.37.In addition to having almost the same safety factor, 4 x4 hollow steel with a thickness of 1.2 mm also has a maximum von Mises stress which is almost the same as 4 x6 hollow steel with a thickness of 1 mm, namely 51.34 MPa and 50.37 MPa, respectively.

Displacement
There is a significant difference between 4 x4 hollow steel with a thickness of 1.2 mm and 4 x6 hollow steel with a thickness of 1 mm in the displacement analysis.Despite having the same weight, the 4 x4 hollow steel experienced a larger displacement of 0.84 mm, while the 4x6 hollow steel with a thickness of 1 mm only experienced a displacement of 0.44 mm.Therefore, 4x6 hollow steel with a thickness of 1 mm is more recommended to be used as a frame for this electric vehicle.The comparison of displacement total between the four types of materials can be seen in Figure 3.

Figure 2 .
Figure 2. Comparison of von Mises stress analysis (a) hollow 40 x40 with a thickness of 0.8 mm (b) hollow 40 x40 with a thickness of 1 mm (c) hollow 40 x40 with a thickness of 1.2 mm (d) hollow 4 x6 with a thickness of 1 mm

Figure 3 .
Figure 3. Displacement comparison (a) 4 x4 hollow steel with a thickness of 0.8 mm (b) 4 x4 hollow steel with a thickness of 1 mm (c) 4 x4 hollow steel with a thickness of 1.2 mm (d) 4 x6 hollow steel with a thickness of 1 mm 4. Conclusion Based on the simulation results, the following results are obtained:  Frames of steel 40 x 40 with a thickness of 1.2 mm and steel 40 x 60 with a thickness of 1 mm meet the safety factor requirements with values of 4.032 and 4.11  The highest maximum von Mises stress is on a 40 x 40 hollow steel frame with a thickness of 0.8 mm, which is 83.22 MPa, while the lowest maximum von Mises stress is on a 40 x 60 steel 1 mm thick, which is 50.37  The 4x4 hollow steel frame with a thickness of 1.2 mm experienced a displacement of 0.84 mm while the 4x6 hollow steel with a thickness of 1 mm only experienced a displacement of 0.44 mm.Therefore, 4x6 hollow steel with a thickness of 1 mm is more recommended to be used as a frame for this electric vehicle

Table 1 .
Material properties of medium carbon steel used in the

Table 2 .
Simulation results of loading 500 Kg on 4 different material dimensions