Experimental Study of Helical Compression Spring

Transcription

1 Experimental Study of Helical Compression Spring Zeeshan Khutbuddin Shaikh Navsahyadri Faculty of Engineering, Pune Sayyad Asma Naser Vishwabharti college of engineering, Ahemadnagar. ABSTRACT: Helical compression springs basically are mechanical devices which store and release energy. They are used in a wide variety of applications where predictable flexibility is desired. In suspension system when helical compression spring is subjected to axially compressive load it absorbs the energy as well as restoring the initial position of a part after removal of force. In this paper study of static analysis of helical compression spring which is used in light utility vehicle has been done. The spring is studied through the analytical, experimental and finite element analysis to check the deformation and stress behavior. This paper also gives the information about effect of varying the parameters such as number of turns and wire diameter on the spring. The result shows that helical compression spring show nearly linear relationship between the load and deflection for an applied load range. Keywords: Helical compression springs, Deformation and stress behavior, Number of turns, Experimental work. INTRODUCTION: Springs are the elastic machine element /structure components in that they undergo significant deformation when loaded; their compliance enables them to store recoverable mechanical energy. In a vehicle suspension, when the wheel meets an obstacle, the springing allows movement of the wheel over the obstacle and thereafter returns the wheel to its normal position. Compression springs may be cylindrical, conical, tapered, concave or convex in shape and are wound in a helix usually out of round wire. The largest working length of the spring should be appreciably less than the free length to avoid all possibility of contact being lost between spring and structure member, with resulting shock when contact is restore. As the spring approaches solidity, small pitch differences between coils will lead to progressive coil- to- coil contact rather than to sudden contact between all coils simultaneously. Any contact leads to impact and surface deterioration, and to an increase in stiffness. To avoid this, the working length of the spring should exceed the solid length by a clash allowance. The performance of a spring is characterized by the relationship between the loads ( P) applied to it and the deflections ( δ) which result, deflections of a compression spring being considered from the unloaded free length. The P-δ characteristic is approximately linear provided the spring is close coiled and the material elastic. The slope of the characteristic is known as the stiffness of the spring k = P/δ. The designing of spring in a suspension system is very crucial. The analysis is done by considering mass, loads acting on the spring. Comparison is done by varying the wire diameter of the coil spring to verify the best dimension for the spring. Spring Terminology: D o Outer diameter (OD) (in mm) d Wire diameter (in mm) L s Solid height (in mm) P Load (in N) D i - Inner diameter (ID) (in mm) L Free length- (in mm) δ (in mm) K Stiffness (in N/mm) 97 Zeeshan Khutbuddin Shaikh, Sayyad Asma Naser

2 LITERATURE REVIEW: Supriya Burgul [1] Author gives reviewed some papers on the design and analysis spring performance and fatigue life prediction of spring. There is also the analysis of failure in spring. it is found that fiberglass material has better strength characteristic and lighter in weight as compare to steel for spring. Rajkumar V. Patil, P. Ravinder Reddy and P. Laxminarayana [2]In this paper the author presents an efficient two nodes finite element with six degrees of freedom per node, capable to model the total behavior of a helical spring. The working on this spring is subjected to different cases of static and dynamic loads and different type of method (finite element method, dynamic stiffness matrix method) is governing equations by the motion of helical spring. This element permits to get the distribution of different stresses along the spring and through the wire surface without meshing the structure or its surface. Figure 1: Buckling Load and s of the Non-telescopic Conical Springs [2] Ahmed Ibrahim Razooqi, Hani Ameen, Kadhim Mijbel Mashloosh [3] In this paper the author presents Helical and slotted cylinder springs are indispensable elements in mechanical engineering. This paper investigates helical and slotted cylinder springs subjected to axial loads under static and dynamic conditions. The objective is to determine the stiffness of a circular cross-section helical coil compression spring and slotted cylinder springs with five sizes and dynamic characteristics. A theoretical and finite element models are developed and presented in order to describe the various steps undertaken to calculate the spring s stiffness. Five cases of the spring s geometric are presented. A finite element model was generated using ANSYS software and the stiffness matrix evaluated by applying a load along the spring s axis, then calculating the corresponding changes in deformation. METHODOLOGY: I. Analytical method: For designing the helical compression spring following formulae has been use Spring index, C = D/d Wahl factor, K = +. Maximum shear stress, = ( ) Torsional shear stress, τ 1 = Direct shear stress, τ 2 = Resultant shear stress, τ R = τ1 + τ 2 in the spring, δ= Rate of the spring, k = Total gap = ( 1) gap between two adjacent coils Solid length = Free length = solid length + total gap + Pitch of the coil, p = ( ) 971 Zeeshan Khutbuddin Shaikh, Sayyad Asma Naser

3 EXPERIMENTAL WORK: Fig.2:Universal Testing Machine Fig.3: Computer Fig.4: Clamping of spring Fig.5: Upper mounting Fig.6: Test specimen Case I: Pitch=62mm Wire diameter=12mm Table 1: spring specifications Case II: Pitch=62mm Wire diameter=12mm Outer diameter=132.5mm Inner diameter=19.5mm Free length=319mm Total no. of turns=6 Active no. of turns=5 Outer diameter=132.5mm Inner diameter=19.5mm Free length=298mm Total no. of turns=5 Active no. of turns=4 972 Zeeshan Khutbuddin Shaikh, Sayyad Asma Naser

4 Sr. no. Load (N) 1 Case I International Journal of Engineering Technology Science and Research Table 2: Experimental data 2 3 Load (N) Case II (mm) 2 (mm) 3 (mm) 1 (mm) 2 (mm) Graph No.1: load vs. deflection, case I Graph No. 2:load vs. deflection, case II TH Ex TH Ex Graph No.3: load vs. deflection, comparison case I Graph No.4: load vs. deflection, comparison case II K 1 = P/δ= 3557/17.77= 2.8 K 2 = P/δ = 3557/147.1= Zeeshan Khutbuddin Shaikh, Sayyad Asma Naser

5 CATIA Model of spring: By Using CATIA V5R17 Software Create the CATIA Model of spring International Journal of Engineering Technology Science and Research Fig.7: Catia model of Test specimen Case I Finite Element Analysis of spring Case III Case II Case IVs CONCLUSION: The helical coil spring of Tata e v2 were studied by analytical, experimental and by finite element analysis for four different cases. The values of deflection of all cases are compares. It is observed that under all the cases deflections are linearly proportional to the applied load. Also the Finite Element Analysis results prove that the values of deflection of suspension spring are close to the theoretical as well as experimental with + 1% variation. 974 Zeeshan Khutbuddin Shaikh, Sayyad Asma Naser

6 There are various parameters which are also influencing the life or capacity of the spring those are number of turns, types of material, microstructure, chemical coating, and surface residual compressive stress etc.the stiffness of the spring is considered as a `response' parameter for validation. Theoretical Stiffness = K = 24.1 N/mm. Experimental Stiffness case I = K 1 = 2.83 N/mm. Experimental Stiffness case II = K 2 = N/mm. REFERENCES: [1] SupriyaBurgul, Literature Review on Design, Analysis and Fatigue Life of a Mechanical Spring,vol.2 issue.7,july 214,pgs: [2] Rajkumar V. Patil, P. Ravinder Reddy and P. Laxminarayana, Comparison of Cylindrical and Conical Helical Springs for their Buckling Load and,vol.73 (214), pp [3] Ahmed Ibrahim Razooqi, Hani Aziz Ameen, Kadhim Mijbel Mashloos, Compression and impact characterization of helical and slotted cylinder springs, international Journal of Engineering & Technology,3(2) (214) [4] Pinjarla.Poornamohan, LakshmanaKishore.T, DESIGN AND ANALYSIS OF A SHOCK ABSORBER, ISSN: [5] Gajendra Singh Rathore, Upendra Kumar Joshi, FATIGUE STRESS ANALYSIS OF HELICAL COMPRESSION SPRING:AREVIEW,Issue 3, Vol.2 (May 213), ISSN [6] Prince Jerome Christopher J.,Pavendhan R., Design and Analysis of Two Wheeler Shock Absorber Coil Spring. [7] Kommalapati, Rameshbabu, TippaBhimasankaraRao, Design Evaluation of a Two Wheeler Suspension System for Variable Load Conditions,Vol, 3 Issue, 4. [8] P.N.L.Pavania, B.K.Prafullab, R.Pola Raoc, S.Srikirand, Design, Modeling and Structural Analysis of Wave Springs, Procedia Materials Science 6 ( 214 ) [9] P. D. Belapurkar, S.D. Mohite, M.V. Gangawane, D. D. Doltode, Development and Comparison of Manual Spring Testing Machine with Universal Testing Machine, e-issn: ,p-ISSN: X PP [1] Sangmesh Pattar, Sanjay S.J, V.B.Math, Static Analysis of Helical Compression Spring, eissn: pissn: [11] Mr. Amit A. Hingane1 Prof. Dr. S. H. Sawant, Static Analysis of Helical Compression Spring Used In Vibration Absorber with Nonlinear Parameters, Vol. 2, Issue 4, 214 ISSN (online): [12] Logavigneshwaran S.1, Sriram G.2, Arunprakash R.3, Design and Analysis of Helical Coil Spring in Suspension System, Volume 9 Issue 1 September ISSN: [13] Olugboji Oluwafemi Ayodeji, Matthew Sunday Abolarin, Jiya Jonathan Yisa,Alaya Garba Muftau, Ajani Clement Kehinde, Design and Construction of a Spring Stiffness Testing Machine,e-ISSN: p-issn : ,215. [14] ChandgudeViresh V, Chat tar Nilesh G, ChaudhariSharad B, Gaikwad Vicky B, BhaneAjit B, Modern Hydraulic Spring Stiffness Testing Machine, Issn , ISO 91:28,216. [15] Dhiraj V. Shevale, Niranjan. D. Khaire, Review on Failure Analysis of Helical Compression Spring, ISSN: , Volume 5, Issue 4, April 216. [16] Aakash Bhatt, Anil Devani, ParthZalavadiya, Design analysis of helical spring of suspension System, 216 IJEDR Volume 4, Issue 3 ISSN: [17] N.Lavanya, P. Sampath Rao M.Pramod Reddy, Design and Analysis of A Suspension Coil Spring For Automotive Vehicle, ISSN: , Vol. 4, Issue 9(Version 5), September 214, pp [18] Niranjan Singh, General Review Of Mechanical Springs Used In Automobiles Suspension System E-Issn [19] Mohd Izaham Zainal Abidin, Jamaluddin Mahmud, Mohd Juzaila AbdLatif Aidah Jumahat, Experimental and Numerical Investigation of SUP12 Steel CoilSpring, Procedia Engineering 68 (213) [2] Harshal Rajurakar,M. C. Swami, Analysis Of Helical Compression Spring For Two Wheeler Automotive Rear Suspension, e-issn: ,p-ISSN: X, Volume 13, Issue 2 Ver. II (Mar. - Apr. 216). 975 Zeeshan Khutbuddin Shaikh, Sayyad Asma Naser