Design Evaluation & Optimization of a Two-Wheeler Suspension System

Transcription

1 Design Evaluation & Optimization of a Two-Wheeler Suspension System Setty Thriveni 1, G. Ranjith Kumar 2, Dr. G. Harinath Gowd 3 1,2 PG Student, 3 Professor, Department of Mechanical Engineering, Madanapalle Institute of Technology & Science, Madanapalle. Andhra Pradesh., INDIA Abstract--A suspension system or shock absorber is a mechanical device designed to smooth out or damp shock impulse, and dissipate kinetic energy. In a vehicle, it reduces the effect of traveling over rough ground, leading to improved ride quality, and increase in comfort due to substantially reduced amplitude of disturbances. In suspension framework spring configuration is exceptionally paramount as it impacts the riding consolation in a time of distress and in the general weight of the vehicles. For the present work, the mono suspension system at present using in various two wheelers is chosen for study. The present work focuses mainly on obtaining the optimal spring dimensions without affecting the riding comfort for mono suspension system. To meet the above objective, first the existing springs of Honda CB Unicorn & Yamaha FZ springs will be tested for its strength by conducting the compression test. Later its 3D model drawn using SOLIDWORKS will be imported to HYPERMESH for meshing the spring & to apply the required loads on it. Finally by importing it into the ANSYS software to evaluate the stresses, strains and its load carrying capacity by doing static analysis. Mainly, this paper deals with the coil spring which is used in the Mono Suspension system. Then further analysis using the above softwares will be done by changing the spring dimensions and by using alternate materials. Thereby the optimal dimensions will be identified. Keywords--Ansys, Hyper mesh, Mono Suspension System, Optimization & Solid works. I. INTRODUCTION Suspension framework serves to store strain energy by avoiding themselves when the wheels go over any knock out and about. As soon as the wheels go off the bump, the spring rebound back owing it their inherent elastic action. The automobile frame & body is attached to the front & rear axle by suspension system which minimizes the effect of road shocks transmitted to the frame, thus protecting the various working parts of the vehicle and the occupants of a motor vehicle. Suspension system consists of a spring & a damper (shock absorber). The theoretical calculations are given below. Material: Spring Steel Consider, Weight of the bike= 125 kgs Weight of 2 persons = 75*2 =150 kgs Rear suspension weight 65% For Single shock absorber Weight = W/2 = 1617N Maximum stress induced in the spring S max = Where C = Spring Index = D/d And Spring Rate k = For Honda Spring S max = N/mm For Yamaha Spring S max = N/mm For Case-1 Spring S max = N/mm For Case-2 Spring S max = N/mm Here both the springs has varying pitches for varying heights. II. MODELING Solid works Organization was established in December 1993 by Massachusetts Foundation of Engineering graduate Jon Hirschtick. Jon Hirschtick selected a group of specialists to fabricate an organization that created 3d Scoundrel programming that was not difficult to utilize. The Solid works application is a mechanical configuration robotization programming bundle used to make parts, gatherings, and drawings which exploit the recognizable Microsoft Windows graphical client interface. Solid Works is a simple to learn configuration and dissection instrument, (COSMOS Xpress, COSMOS Works, Universe Flo Works, and COSMOS Motion) which makes it workable for architects to rapidly draw 2d and 3d ideas, make 3d sections and get-togethers, and subtle element 2d drawings. In Solid Works part, gathering, and drawing reports are all related. Here the spring has been demonstrated with present HONDA CB UNICORN measurements on Solid Works- 11. Based on the stresses developed in the above springs, new springs have been modified with new dimensions to reduce the stresses. 370

2 Case: 2 And here the Honda dimensions are modified for reducing the stresses. For both the cases 3D model is developed using Solid works and then analysis is done using ANSYS. Fig. 1: Honda Spring (3D Model) Fig. 4: Case-2 Fig. 2: Yamaha (3D Model) Case: 1 Here the dimensions of existing springs have been considered for modifications. By changing the dimensions of above springs the new spring has been modified as below. Fig. 3: Case-1 III. INTRODUCTION TO FEA Finite Element Analysis (FEA) was initially created in 1943 by R. Courant, who used the Ritz technique for numerical investigation and minimization particle of variational math to get rough answers for vibration frameworks. In no time from that point, a paper distributed in 1956 by M. J. Turner, R. W. Clough, H. C. Martin, and L. J. Topp made a more extensive meaning of numerical dissection. The paper fixated on the "firmness and avoidance of complex structures". By the early 70's, FEA was constrained to extravagant centralized server workstations for the most part claimed by the aeromechanics, auto, barrier, and atomic businesses. Since the quick decrease in the expense of machines and the uncommon build in registering force, FEA has been created to an amazing exactness. Present day supercomputers are presently equipped to create correct results for numerous types of parameters. FEA comprises of a machine model of a material or outline that is focused on and examined for particular results. It is utilized within new item outline, and existing item refinement. An organization can confirm a proposed outline will have the capacity to perform the customer's specificity particles before assembling or development. Altering a current product or structure is used to qualify the product or structure for another administration condition. 371

3 If there should be an occurrence of structural disappointment, FEA may be utilized to assist focus the configuration adjustments to meet the new condition. There are by and large two sorts of examination that are utilized as a part of industry: 2-D demonstrating, and 3-D displaying. While 2-D demonstrating saves straightforwardness and permits the investigation to be run on a moderately ordinary workstation, it has a tendency to yield less correct results. 3-D demonstrating, notwithstanding, delivers more correct results while relinquishing the capability to run on everything except the speediest machines successfully. Inside each of these displaying plans, the developer can embed various calculations (capacities) which may make the framework act directly or non-straightly. Straight frameworks are far less intricate and for the most part don't consider plastic distortion. Non-straight frameworks do represent plastic deformity, and a lot of people likewise are equipped for testing a material the distance to crack. FEA utilizes a complex arrangement of focuses called hubs which make a framework called a cross section. This cross section is modified to hold the material and structural properties which characterize how the structure will respond to certain stacking conditions. Hubs are allocated at a certain thickness all through the material relying upon the foreseen anxiety levels of a specific range. Areas which will get a lot of anxiety generally have a higher hub thickness than those which encounter practically zero anxiety. Purposes of investment may comprise of: break purpose of beforehand tried material, filets, corners, complex subtle element, and high stretch ranges.the mesh acts like a spider web in that from each node, there extends a mesh element to each of the adjacent nodes. This web of vectors is what carries the material properties to the object, creating many elements. Many FEA programs also are equipped with the capability to use multiple materials within the structure such as: Isotropic, identical throughout Orthotropic, identical at 90 degrees General anisotropic, different throughout Both springs have been meshed in the hypermesh14.0 by using the tetra mesh tool. The meshed models are shown below. Fig. 5: Meshed model of Honda Fig. 6: Meshed model of Yamaha Fig. 7: Meshed model for Case-1 372

4 (3) Post processing: further preparing and review of the results In this stage one may wish to see (i) arrangements of nodal relocations, (ii) component strengths and moments, (iii) diversion plots, and (iv) stress shape outlines or temperature maps The following diagrams illustrate about the vonmises stresses of the all springs Fig. 8: Meshed model for Case-2 IV. RESULTS AND DISCUSSION ANSYS is an universally useful limited component demonstrating bundle for numerically unraveling a wide mixed bag of mechanical issues. These issues incorporate static/dynamic, structural investigation (both linear and nonlinear), high temperature exchange, and liquid issues, and additionally acoustic and electromagnetic issues. Generally, a finite-element solution may be broken into the accompanying three stages. (1) Preprocessing: defining the problem, (2) Solution: assigning loads, constraints, and solving (3) Post processing: further processing and viewing of the results Fig. 9: Honda (1) In the preprocessing, the following are the major steps involved (i) Defining key points / lines / areas / volumes, (ii) Defining element type and material/geometric properties, and iii) Mesh lines / areas / volumes as required. The measure of subtle element needed will rely on upon the dimensionality of the analysis, i.e., 1D, 2D, axisymmetric, and 3D. (2) Solution: allotting loads, conditions, and settling Here, it is important to define the loads (point or weight), conditions (translational and rotational), lastly explain the ensuing set of mathematical statements. Fig. 10: Yamaha 373

5 In the span of service life of spring it undergoes the varying loads. Springs has been designed in Design software SolidWorks. In this paper shear stress equation is used for calculating the maximum stress induced in the spring. Comparison has been made for theoretical results obtained from the shear stress equation to the Finite Element Analysis (FEA) results. In both the cases the analysis results gives the better results than the existing one. By these FEA results gives the better accuracy. There is a chance for Investigations to be made on different alternate available suitable materials to achieve the overall weight reduction of the automobile without affecting the riding comfort of the two-wheeler suspension. Fig. 11: Case-1 Fig. 12: Case-2 V. CONCLUSION The literature review has been discussed about the design of mechanical springs used in suspension systems is used to do it s deign analysis which involves maximum stress analysis. REFERENCES [1] R.S. Khurmi & J.K Gupta (2003), A textbook of machine design, S. Chand & company. [2] Kommalapati. RameshBabu, 2. Tippa Bhimasankara Rao. Design Evaluation of a Two Wheeler Suspension System for Variable Load Conditions International Journal of Computational Engineering Research Vol. 03 Issue 4 April, [3] S. Segla1 S. Reich2. Optimization and comparison of passive, active, and semi-active vehicle suspension systems 12th IFToMM World Congress, Besançon (France), June18-21, [4] Pinjarla.Poornamohan 1, Lakshmana Kishore.T 2. Design and Analysis of a Shock absorber ISSN: Volume: 1 Issue: [5] First edition of Practical Finite Element Analysis by Nitin S Gokhale, Sanjay S Deshpande, Sanjeev V Bedekar, Anand N Thite. [6] [7] P.S.Valsange Design Of Helical Coil Compression Spring A Review (IJERA) Vol. 2, Issue 6, November- December 2012, pp [8] Niranjan Singh General review of mechanical springs used in Automobiles suspension system Singh, international journal of advanced engineering research and studies, E-ISSN , Int. J. Adv. Engg. Res. Studies/iii/i/oct.-dec.,2013/ Review article [9] Adam G. Rasbach, Orion, MI (US). United States Patent Application Publication Pub. N0.: US 2013/ A1 Rasbach (43) Pub. Date: May 23,