scholarly journals Design and Non-Linear Analysis of a Parabolic Leaf Spring

1970 ◽  
Vol 37 ◽  
pp. 47-51 ◽  
Author(s):  
Muhammad Ashiqur Rahman ◽  
Muhammad Tareq Siddiqui ◽  
Muhammad Arefin Kowser
Keyword(s):  
Geometric Nonlinearity ◽  
Maximum Stress ◽  
Large Deflection ◽  
Linear Analysis ◽  
Leaf Spring ◽  
Cantilever Beams ◽  
Leaf Springs ◽  
Non Linear ◽  
Fixed End ◽  
Parabolic Leaf Spring

Tapered cantilever beams, traditionally termed as leaf springs, undergo much larger deflections in comparison to a beam of constant cross-section that takes their study in the domain of geometric nonlinearity. This paper studies response of a leaf spring of parabolic shape, assumed to be made of highly elastic steel. Numerical simulation was carried out using both the small and large deflection theories to calculate the stress and the deflection of the same beam. Non-linear analysis is found to have significant effect on the beam's response under a tip load. It is seen that the actual bending stress at the fixed end, calculated by nonlinear theory, is 2.30-3.39% less in comparison to a traditional leaf spring having the same volume of material. Interestingly, the maximum stress occurs at a region far away from the fixed end of the designed parabolic leaf spring. Keywords: Parabolic leaf spring, End-shortening, Geometric nonlinearity, Equilibrium Configuration Path, Varying Cross-section.doi:10.3329/jme.v37i0.819Journal of Mechanical Engineering Vol.37 June 2007, pp.47-51

Study on the stiffness property of a variable stiffness joint using a leaf spring

2018 ◽  
Vol 233 (3) ◽  
pp. 1021-1031 ◽  
Author(s):  
Lijin Fang ◽  
Yan Wang
Keyword(s):  
Geometric Nonlinearity ◽  
Large Deflection ◽  
Elliptic Integral ◽  
Joint Stiffness ◽  
Variable Stiffness ◽  
Leaf Spring ◽  
Stiffness Property ◽  
Force Structure ◽  
Leaf Springs ◽  
Application Requirements

Variable stiffness joints designed to ensure physical safety or adjust stiffness actively have attracted much attention in recent years. Springs are used in the internal kinematic structures of variable stiffness joints to achieve the compliance. In this paper, the stiffness property of a variable stiffness joint using a leaf spring is studied on the basis of geometric nonlinearity associated with large deflections of leaf springs. A new end structure is used in the variable stiffness joint to exert the external force on the leaf spring. Based on the elliptic integral solution to large deflection problems of cantilever beams, the effects of different end exertion force structures and geometric nonlinearity of leaf springs on the stiffness property are analyzed when the deflected angle of the joint is larger. It is found that the end exertion force structure and large deflection of leaf springs have a great impact on the changes of the joint stiffness during the joint deflection. A new variable stiffness joint using two leaf springs is proposed to meet different application requirements by changing the end exertion force structure. The experiment of the proposed joint is carried out to verify the validity of the stiffness analysis results.

Effect of End Rubber Gasket on the Performance of Parabolic Leaf Spring

2020 ◽  
Author(s):  
Junhong Zhang ◽  
Feiqi Long ◽  
Hongjie Jia ◽  
Jiewei Lin
Keyword(s):  
Ride Comfort ◽  
Orthogonal Experiment ◽  
Element Model ◽  
Considerable Effect ◽  
Leaf Spring ◽  
Static Stiffness ◽  
Rubber Gasket ◽  
Maximum Deformation ◽  
Leaf Springs ◽  
Parabolic Leaf Spring

Abstract Leaf springs play an important role in the handling stability and ride comfort of vehicle. End rubber gaskets are widely used to reduce the friction between leaves, but they also have considerable effect on the stiffness of the suspension assembly. The ride comfort may deteriorate with the stiffness of leaf spring changes. In this paper the influence of the end rubber gasket on the static stiffness performance of a parabolic leaf spring is studied. A finite element model of the leaf spring is developed and verified against the static stiffness test. Effects of the end rubber gasket parameters on the static stiffness of the leaf spring are analyzed based on an orthogonal experiment. The sensitivities of the five parameters are identified including the width, the length, the end thickness, the tail thickness and the distance to the end of the middle leaf. It is found that the contributions can be ranked in descending order as the tail thickness, the end thickness, the distance from end rubber gasket to the end of Leaf 2, and the width and length. The first two factors are considered of significant effects on the leaf spring stiffness. According to single-factor analysis, it is found that under the same load, as the tail thickness and the end thickness increase, the maximum deformation of the rubber gasket decreases, the stiffness of the rubber gasket increases, and the stiffness of the leaf spring increases, which provides a reference for the forward design of the end rubber gasket and the stiffness matching of leaf springs.

scholarly journals Effect of Assembly Stresses on Fatigue Life of Symmetrical 65Si7 Leaf Springs

2014 ◽  
Vol 2014 ◽  
pp. 1-10
Author(s):  
Vinkel Kumar Arora ◽  
Gian Bhushan ◽  
M. L. Aggarwal
Keyword(s):  
Fatigue Life ◽  
Maximum Stress ◽  
Testing Machine ◽  
Vital Role ◽  
Design Parameters ◽  
Leaf Spring ◽  
Leaf Springs ◽  
Light Commercial Vehicle ◽  
Load Rate ◽  
Suitable Combination

The maximum stress induced plays vital role in fatigue life improvement of leaf springs. To reduce this maximum stress, leaves with different unassembled cambers are assembled by pulling against each other and a common curvature is established. This causes stress concentration or sets assembly stress in the assembled leaf springs which is subtractive from load stress in master leaf while it is additive to load stress for short leaves. By suitable combination of assembly stresses and stepping, it is possible to distribute the stress and improve the fatigue life of the leaf spring. The effect of assembly stresses on fatigue life of the leaf spring of a light commercial vehicle (LCV) has been studied. A proper combination of stepping and camber has been proposed by taking the design parameters into consideration, so that the stress in the leaves does not exceed maximum design stress. The theoretical fatigue life of the leaf springs with and without considering the assembly stresses is determined and compared with experimental life. The numbers of specimens are manufactured with proposed parameters and tested for load rate, fatigue life on a full scale leaf springs testing machine. The effect of stress range, maximum stress, and initial stress is also discussed.

scholarly journals Experimental and numerical analysis of the static strength and fatigue life reliability of parabolic leaf springs in heavy commercial trucks

2020 ◽  
Vol 12 (7) ◽  
pp. 168781402094195
Author(s):  
Ufuk Taner Ceyhanli ◽  
Mehmet Bozca
Keyword(s):  
Finite Element ◽  
Fatigue Life ◽  
Numerical Analysis ◽  
Reliability Analysis ◽  
Static Loading ◽  
Static Strength ◽  
Design Stage ◽  
Leaf Spring ◽  
Leaf Springs ◽  
Parabolic Leaf Spring

The objective of this study is to perform experimental and numerical analysis of the static strength and fatigue life reliability of parabolic leaf springs in heavy commercial trucks. To achieve this objective, stress and displacements under static loading were analytically calculated. A computer-aided design model of a parabolic leaf spring was created. The stress and displacements were calculated by the finite element method. The spring was modelled and analysed using CATIA Part Design and ANSYS Workbench. The stress and displacement distributions on a three-layer parabolic leaf spring were obtained. The high-strength 51CrV4 spring steel was used as sample parabolic leaf springs material, and heat treatments and shoot peening were applied to increase the material strength. Sample parabolic leaf springs were tested to obtain stress and displacement under static loading conditions. By comparing three methods, namely, the static analytical method, static finite elements method and static experimental method, it is observed that results of three methods are close to each other and all three methods are reliable for the design stage of the leaf spring. Similarly, sample parabolic leaf springs were tested to evaluate the fatigue life under working conditions. The reliability analysis of the obtained fatigue life test value was carried out. It was shown that both analytical model and finite element analysis are reliable methods for the evaluation of static strength and fatigue life behaviour in parabolic leaf springs. In addition, it is determined by a reliability analysis based on rig test results of nine springs that the spring achieves its life cycle of 100,000 cycles with a 99% probability rate without breaking. Furthermore, the calculated fatigue life is 2.98% greater than experimentally obtained fatigue life mean and the leaf spring can be used safely and reliably during the service period in heavy trucks.

scholarly journals Combined Effects of Geometric and Material Non—linearities on One Dimensional Structural Members

2018 ◽  
Vol 1 (1) ◽  
pp. 5-8
Author(s):  
R.Ramgopal Varma ◽  
G. Venkateswazra Rao
Keyword(s):  
Large Deflection ◽  
Compressive Load ◽  
Linear Analysis ◽  
Combined Effects ◽  
Structural Members ◽  
Axial Compressive Load ◽  
Linear Behavior ◽  
Non Linear ◽  
Deflection Analysis ◽  
Convergence Study

Combined effects of geometric and material non-linearities on a uniform column subjected to an axial compressive load are presented in the present note. A simple, direct iterative numerical method has been proposed to study the geometric and material non-linear behavior of columns subjected to varying boundary conditions. Introduction of material non-linearity in the large deflection analysis of columns subjected to an axial compressive load reveals a reduction in Euler stress obtained when compared to the effect of geometric non-linear analysis and increase in the same when compared to the eflect of material non-linear analysis. A convergence study has been carried outfor the results obtained from the proposed iterative method to prove the efficacy.  

scholarly journals Behavioural Study of Thin Plate Under Large Deflection Theory

2021 ◽  
pp. 322-329
Author(s):  
Darshni B ◽  
Senthil Kumar V
Keyword(s):  
Thin Plate ◽  
Geometric Nonlinearity ◽  
Analytical Study ◽  
Large Deflection ◽  
Linear Analysis ◽  
Fe Model ◽  
Ansys Software ◽  
Edge Conditions ◽  
Deflection Theory ◽  
Large Deflection Theory

For a thin plate, if the deformation is on the order of the thickness and stay elastic, linear theory might not turn out correct results because it does not predict the in plane movement of the member. Therefore, to account for the inconsistencies of geometric nonlinearity, large deflection theory is required [1]. This report pertains to the analytical study dispensed to check the behavior of thin plate under fixed and pinned edge conditions, and for diverse thicknesses, under the small and large deflection theories. The deformation is additionally studied, supported by Von-Karman equations. Non linear analysis has been performed on FE model using the ANSYS software. The consequences of geometric nonlinearities are mentioned. Outline on conclusion of the theoretical and experimental results obtained, are compared so as to review the similarity of the modeling and theory.

Failure Analysis of a Fractured Leaf Spring as the Suspension System Applied on the Dump Truck

2021 ◽  
Vol 892 ◽  
pp. 89-98
Author(s):  
Husaini ◽  
Rizqi Handayani Liza ◽  
Ali Nurdin ◽  
Sadrawi Muammar
Keyword(s):  
Finite Element ◽  
Maximum Stress ◽  
Suspension System ◽  
Leaf Spring ◽  
Dump Truck ◽  
Element Analysis ◽  
Leaf Springs ◽  
Rigid Rods ◽  
Cause Of Failure ◽  
Vehicle Suspension System

A spring is a component which is designed to have relatively low stiffness compared to normal rigid rods, thereby making it possible to accept certain forces that are charged. A leaf spring is an important suspension component for heavy vehicles, as a failure of the leaf spring can cause severe if not fatal accidents. This study aims to investigate the factors that cause leaf spring failure in the form of a 125 PS dump truck vehicle suspension system. The method employed incorporated experimental and finite element analyses. The experimental work included visual observations, observation using a scanning electron microscope (SEM), hardness testing, and microstructure testing. Leaf spring modelling was conducted using Autodesk Inventor 2017 software, and the finite element analysis (FEA) was performed using Siemens ™ FEMAP V12.0.1 application software to calculate the maximum stress and strain that occurred near the crack tip of the leaf spring. The results from the analysis indicated that the cause of the fracture that occurred in leaf spring No. 3 was due to a defect discovered on the surface of the leaf spring. Based on the observations of the fracture surface, it is revealed that the cause of failure was due to the cyclic load experienced by the components during operation which caused crack propagation beginning from micro-cracks until reaching a significant dimension to cause a final fracture. In addition, the overload imposed on the leaf springs also caused maximum stress on the springs to increase, thus accelerating the failure of the leaf springs. Further results also showed that the value of the stress intensity factor, KI = 29.15 MPa.m1/2 was greater than the value of fracture toughness, KIC = 23 MPa.m1/2 of the spring material.

Evaluation of modal parameters and static characteristics for composite mono leaf spring

2020 ◽  
pp. 095745652096488
Author(s):  
Ehab Samir Mohamed Mohamed Soliman
Keyword(s):  
Finite Element ◽  
Maximum Stress ◽  
3D Models ◽  
Modal Parameters ◽  
Leaf Spring ◽  
Static Characteristics ◽  
Element Analysis ◽  
Conventional Steel ◽  
Leaf Springs ◽  
Composite Mono Leaf Spring

The objective of this paper was to investigate and evaluate modal parameters and static characteristics for designed carbon/epoxy composite CFRP leaf spring made from carbon fiber-reinforced epoxy by comparing its finite element analysis FEA modal, harmonic and static results to that of conventional steel one under the same maximum full bump load. In ANSYS software, finite element modal, harmonic and static analysis for 3D models of conventional steel and designed composite mono leaf springs is carried out. FEA displacements for the steel and designed composite CFRP mono leaf springs at the maximum full bump load were 92.9 mm and 93.1 mm respectively. Compared to the steel mono leaf spring, the composite mono leaf spring has advantages; lower stresses, higher natural frequencies and higher safety in stresses of front and rear eyes. All these advantages let the composite leaf spring can be carried maximum full bump load with enough higher performance over steel one to avoid resonance and satisfy maximum stress failure criterion.

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