An Numerical Investigation of Open Coil Helical Compression Spring Using Different Alloys Materials for Light Duty Vehicle

The main purposes of automobile open coil suspension systems are to isolate the chassis of the vehicle and the passenger from shocks and vibrations caused by irregularities of the road surface. The main objective of this work is to concentration on the stress and deflection of open coil helical spring used in light vehicle suspension spring with different materials. Finite Element Analysis of open coil helical spring has been carried out. In FEA 3D modeling is done in SOLIDWORKS and analysis is in ANSYS software. From the ANSYS results, it is observed that the maximum deflection in the Chrome Vanadium spring is 217.47 mm and in Chrome Silicon and Hard drawn steel springs are 212.83 mm and 212.36 mm respectively. From the ANSYS results, it also seen that the shear stress in the Chrome Vanadium spring is 757.21 MPa and in Chrome Silicon and Hard drawn steel springs are 753.65 MPa and 761.32 MPa respectively. From ANSYS results the maximum shear stress of Chrome Silicon alloy steel spring is less compared to Chrome Vanadium and Hard Drawn alloy steel spring.


Introduction
Mechanical springs are used in machines to exert forces, to afford elasticity, and to store or absorb energy. In general, open coil helical springs is classified as coil springs, leaf springs or special shaped springs. Most of the vehicles have open coil helical compression spring as one of the main elastic members in their suspension systems. They act as an energy absorbing machine element. The prime aim of a vehicle suspension system is to connect the wheel to the body. Suspension system of automotive vehicle is very needful part, they are responsible to absorb road shock and isolated passenger curb to road shock, comfort, safety, handling, road holding and ride quality. Investigated on springs design as the determination of the geometry, dimensions, and stiffness of a spring needed to satisfy the force-deflection requirements [1,2]. The analyzed reduction of overall stress and deflection of Chrome Vanadium and 60Si2MnA steel. It is observed that the 60Si2MnA [3,4,5]. Stress and deflection of existed steel helical compression spring and new material. It is observed that reduction of stress and deflection in new material [6]. The modal and structural analysis was done on spring steel and Phosphor Bronze. Finally authors conclude that steel material for spring is best [7]. The open coiled helical compression materials has been used for Chrome Vanadium steel material, Chrome  [8,9]. Based on the dimensions obtained from the conventional helical compression spring was created with the help of the 3D modeling SOLIDWORKS software. The main objectives of this work are to reduce the overall deflection and stresses of the open coil helical compression spring by finite element approach.

Materials and Methods
In this Finite Element Analysis model is prepared in SOLID WORK 15 and save as in IGES file format. Then its IGES format file is imported in ANSYS WORKBENCH 15.0. In ANSYS 15.0 material properties, meshing and boundary condition is given. In this solution deformation and stress are simulated. These calculations carried out for the chosen materials for spring steels such as Chrome

Results and discussions
The simulated results of deformation and stress are discussed. These calculations carried out for the chosen materials for spring steels, viz., Chrome Vanadium, Chrome Silicon and Hard Drawn alloy steel for minimum and maximum load conditions. The results obtained for various considerations are compared for the three materials chosen.

Static Analysis of Hard Drawn Steel
From the FE analysis, the maximum deflection and shear stress under 3234N are 106.18 mm and 380.66 MPa respectively shown in Figure 11a and Figure 11b.    Table 1 and for minimum load conditions in Table 2.

Comparison of Finite Element Analysis Results
The comparison of FEA results for deflection and shear stress under different loads on Chrome Vanadium, Chrome Silicon and Hard Drawn spring are shown in Table 1 and Table 2. When applied loads are increase the deflection and shear stress also increased.

Conclusions
The helical coil spring of chrome silicon, chrome vanadium and hard drawn spring steel are studied using FE analysis. The shear stress and deflection values are have been calculated using finite element analysis for Chrome Silicon, Chrome Vanadium and Hard Drawn spring steel. It is observed the maximum deflection in the Chrome Vanadium spring is 217.47 mm and in Chrome Silicon and Hard drawn steel springs are 212.83 mm and 212.36 mm respectively. From the ANSYS results, it also seen that the shear stress in the Chrome Vanadium spring is 757.21 MPa and in Chrome Silicon and Hard drawn steel springs are 753.65 MPa and 761.32 MPa respectively. The FEA results proves that even though the maximum deflection are almost close the value but the maximum shear stress of Chrome Silicon steel spring is less and comparative to the Chrome Vanadium and Hard Drawn steel spring value is high. The above result shows that the Chrome Silicon is best replacement for chrome vanadium and Hard Drawn steel.