Structural Analysis of Motorcycle Alloy Wheel

Alloy wheels in the motor cycle play major role to carry the load over the spoke wheels. The shape and orientation of the spokes are responsible for withstand the loads which are acting on the alloy wheel rim and hub bearing surface. These alloy wheel spokes are subjected to different types of loads i.e., radial loads, impact load, bending load, torsion load and maximum deflection load. So it is necessary to study the response of the wheel under these types of loads before the product going into the market. In the present article 4 models of motor cycle alloy wheel are modeled based on the dimensions in the reference article. The material chosen for the analysis of the alloy wheel is aluminum alloy which is homogenous in nature having isotropic properties. The magnitude of the five different loading conditions and boundary conditions are taken from the Automotive Industry Standards (AIS). The four models of alloy wheels are analyzed under radial, impact, bending, torsion and maximum deflection loads cases by using by using ANSYS workbench. The results show that all four models are having enough fatigue life, strength and stiffness against the different loading conditions.


INTRODUCTION
Alloy wheel exhibits several advantages over the spoke wheel of the motor cycle. In different conditions these alloy wheels are fails due to insufficient strength and stiffness. In radial load condition, the maximum design load is acts like half sine wave load distribution on the rim surface of the Alloy wheel upon 140 0 contact angle with road. In Impact load condition the load is applied from a certain height to check whether the alloy wheel can withstand the impact force which is result from the speed breakers, etc. In bending load condition, bending moment is calculated upon the automotive industry standards and it is applied on the hub bearing surface to check the alloy wheel whether it is having enough life cycles upon the bending loads. In torsion load case, the torsion is calculated from the AIS and it is applied on the wheel hub bearing surface to check the alloy wheel life cycles under torsion load which is results from the motion of the vehicle. In maximum deflection load condition, the applied load is calculated from the AIS and it is applied on the Alloy wheel hub surface to check whether the alloy wheel is having enough stiffness to withstand the load. The selection of material also plays a major role to with stand the loads in various conditions. In present days all the automobile industries are using aluminum alloy and magnesium alloy. Navuri Karteek [1] perform static and fatigue analysis on different alloy wheel models. He concluded four alloy wheels models out of all having better fatigue life, less damage and better factor of safety under different materials. Shantaram Jadhav [2] performed different loading analysis on the spoke alloy and calculated the life, stresses and deformations. He concluded the spoke wheel is having better life cycles, strength and stiffness against the loads. Later he validated the FEM results with practical results. Sahil Bandral [3] performed impact analysis on the four wheeler alloy wheel and calculated the stresses by varying the number of spokes. He concluded 3 spoke alloy wheel shows better results. Anusha R [4] performed static and impact analysis on the four wheeler alloy wheel and calculated the stresses and deformations. Later performed weight optimization and reduced the weight by 20%. Shwetabh Suman [5] performed impact and modal analysis for different alloy wheel compositions. Results shows alloy wheel with Ti-13 material having less natural frequencies in modal analysis and alloy wheel with Mg-AZ31B material having less deformations in impact analysis. G. V. R Seshagiri rao [6] performed impact analysis on the aluminum alloy wheel and calculated induced stresses. The results show that life of the alloy wheel is maximum at hub and minimum at the rim surface. A Eswara Kumar [7] performed static and modal analysis on the different types of alloy wheel and calculated the results. The results shows that 3 spoke alloy wheel plays better performance in static analysis, while 5 spoke alloy plays better performance in modal analysis.

Problem Statement
To study the life, strength and stiffness of the four different alloy wheel models subjected to variable pressure, impact load, bending load, torsion load and maximum deflection load. The material chosen is aluminum alloy which is homogenous in nature and having isotropic properties.

Geometry
The models of the alloy wheel are selected from the research article [1]. As per the dimensions mentioned in the article, four type alloy wheels are designed. The designed alloy wheels are shown in the below figure.

Coordinate System
Cylindrical coordinate system is assigned to the alloy wheel for applying radial load on the rim surface. The cylindrical coordinate system which is assigned to the alloy wheel are shown in the below figure.

Mesh
Meshing is the process of converting the geometry entities of the alloy wheel in to finite element entities. Proper meshing is done for force and reaction convergence. 8 node hexahedron and 5 node tetrahedron elements are used for meshing operation with a element size of 10 mm. The finite element models of the four different alloy wheels are shown in the below figure. 3.

Loads
The calculations of loads which are applied on the alloy wheel in different cases are discussed below.

Variable Radial Pressure
The variable radial pressure which is applied on the wheel rim surface for 1400 in half sine wave is discussed below.
Average Here the load is applied in variable form and it is assigned in a function form.
Load = Pressure x Sin The load is applied as half sine distribution over the contact angle of 1400 on the wheel rim of the four alloy wheel models. The calculated and applied half sine distribution load on the wheel is shown in the below figure 4. The applied load on the alloy wheel is shown in the below figure 5.0.  The Impact load which is applied from a height of 230 mm height is converted in to the impact force. The impact force is applied on the 50 contact surface of wheel rim. The impact force calculation is discussed below.
Impact load (total mass of striker) is calculated by the following equation    The calculated pressure is applied on the 50 contact angle of alloy wheel rim surface.
The limit of the maximum deflection due to the applied force on the wheel rim surface is listed in the below   10 15 20 The Nominal Rim Diameter of the wheel rim is 6.6304 inch. So the maximum deflection of the alloy wheel should not exceed 15 mm in safe case. The applied load on the wheel rim surface is shown in the below figure 10.0.

Supports
In the radial pressure & impact load case, the boundary conditions are given to the rim surface of the alloy wheel in form of cylindrical support. Linear movements in 2 directions are arrested and free to rotate. The boundary conditions of the alloy wheel in radial pressure and impact load case are shown in the below figure 11.0.

Material
The material selected for the alloy wheel is aluminum alloy which is homogenous in nature and having isotropic properties. The elements which are present in the aluminum alloy are listed in the below table 3.0

Radial Load Case
In the radial load case, the alloy wheel should sustain the load before 5+10^5 life cycles. The calculated von-mises stress of the four different alloy wheels are shown in the below figures.    The loading type is fully reversed type load which having zero mean stress effect. Therefore alternating stress amplitude is directly proportional to the alternating stress.

CONCLUSIONS
The four different alloy wheels are designed as per the dimensions and analyzed under five different loading conditions. The following conclusions are drawn from the above five analysis.

Radial Load Case
The stresses induced in the four different alloy wheels are less than the endurance limit of the material which indicates that the four models experience infinite life cycles.

Impact Load Case
The stresses induced in the four different alloy wheel models are less than the yield strength of the material. Indicates the four alloy wheel models are safe in strength point of view.

Bending load case
The calculated life cycles of the four different alloy wheel models under bending load case are greater than the 100000 life cycles.

Torsion Load Case
The calculated life cycles of the four different alloy wheel models under torsion load case are greater than the 100000 life cycles.

Maximum Deflection load case
The maximum deflection of the alloy wheel is less than the safe limit which is mentioned by the AIS.
From the above conclusions, the four different alloy wheel models are safe in all loading conditions.