Steel Leaf Research Articles

Mechanical Property Testing of Woven Roven Glass Fiber Specimen and Structural Analysis of a Composite Leaf Spring

A Composite material has been fabricated by laying epoxy resin over woven roven fiber mat and carbon fiber combination and its mechanical properties were attained in the Material testing Laboratory. Based on the material properties achieved, A multi-leaf steel spring used in the rear suspension system of light vehicles is designed and analyzed using ANSYS software. The finite element results showing stresses and deflections, verified the existing analytical and experimental solutions. Using the results of the steel leaf spring, a composite one made from Woven glass fiber with epoxy resin was designed and optimized using ANSYS. Main consideration was given to the optimization of the spring geometry. The objective is to obtain a spring with minimum weight that is capable of carrying given static external forces without failure. The design constraints were stresses and displacements. The results show that an optimum spring width decreases hyperbolically and the thickness increases linearly from the spring eyes towards the axle seat. Compared to the steel spring, the optimized composite spring has stresses that are much lower, the natural frequency is higher and the spring weight without eye units is lower and the cost of the composite leaf spring that has been fabricated is comparatively less.

Application of Mono Leaf Spring as a Pipe Support

Leaf springs are one of the oldest forms of springing that is commonly used for the suspension in wheeled vehicles. It is simply adjusted by selecting proper type or number of flat bars. In this study, we are going to show how a mono steel leaf spring can be used as a flexible pipe support in a real situation. It is a cheap and reliable method of support; specifically for the huge pipes in remote areas that maintenance could consider as a big headache. To prove this idea, we will model and test the real situation by using FEA software.

Static Analysis and Fatigue Life prediction of Composite Leaf Spring for a Light Commercial Vehicle (TATA ACE)

In this research work an attempt has been made to check the suitability of composite materials like E- Glass/Epoxy, Graphite/Epoxy, Boron/Aluminum, Carbon/Epoxy and Kevlar/Epoxy for light commercial vehicle leaf spring. First the static analysis is carried out for steel and different composite leaf spring using FE solver ANSYS V10. The obtained results are compared with theoretical values and observed that they have good agreement with each other. The fatigue life of various composite leaf springs is calculated using Hwang and Han relation. From the results it can be concluded that Boron/Aluminum and Graphite/Epoxy are best suitable composite material for leaf spring.

Response of Composite Leaf Springs to Low Velocity Impact Loading

Leaf springs are the traditional suspension elements, occupying a vital position in the automobile industry. This paper deals us the replacement of existing steel leaf spring by composite leaf spring. The dimensions of existing middle steel leaf spring of commercial vehicle (Tata ace mini truck) were taken and fabricated using a specially designed die. Single leaf of the suspension springs, each made up composite with bidirectional carbon fiber reinforced plastic (CFRP), bidirectional glass fiber reinforced plastic (GFRP) and hybrid glass-carbon fiber reinforced plastic (G-CFRP), was fabricated by hand layup process. It is to be mentioned here that the cross sectional area of the composite spring same as the metallic spring. A low velocity impact test rig was fabricated in the laboratory with loading set up. The composite leaf springs were tested with the low velocity impact test rig. By using the low velocity impact test rig, the deflection due to various drop height were measured.

Optimization of Eye End Design of a Single Leaf Spring

This paper is focused on determination of better eye end design and better material among Titanium and Steel for a single leaf spring. The procedure of this work is to carry out computer aided design and analysis of conventional single leaf spring with actual design considerations and loading conditions. This conventional 65Si7 spring steel leaf spring model and Titanium alloy (Ti 6Al 7Nb) with standard eye end, centred eye end and Inverted eye end are considered. The CAD model of the leaf springs is prepared in PRO-E and analysed using ANSYS. Static testing and finite element analysis have been carried out to obtain the characteristics of the spring. The standard eye and centred eye leaf springs are subjected to similar loading conditions. The CAE analysis of the leaf spring is performed for various parameters like Total deflection, von-misses stress and normal stress. The main objective of this work is to determine the better eye end design and select the best material among Steel and Titanium alloy and to reduce the time and cost related to actual experimental testing by providing a CAE solution.

Comparative FEM Analysis of V-Shape and Leaf Springs for Improved Suspension with Part Loading Functionality

The Automobile Industry has shown keen interest for replacement of steel leaf spring with that of progressive rate spring unit, since that has good part loading and minor to maximum shock absorption properties. In this paper we have outline on the new mechanism for progressive rate spring. The main leaf spring and V- shape strip spring model is created by modeling software like Pro-E. The dimensions of an existing conventional steel leaf spring of a light commercial vehicle are taken for modeling. And the structural analysis of both springs is carried via finite element analysis using ANSYS-12 software. Result shows that, the V-shape strip spring has Total deflection 16.93 % & Strain energy 38.20 % more than steel leaf Spring for partly loading. It also shows equivalent von- misses stresses for both spring. It is observed that the V- shape strip spring is great under part loading i.e. minimum loading action and main leaf spring is superior for maximum loading condition so that the whole unit of this progressive rate spring is best suitable for carrying export quality fruit from farm to wear house or customer market and mini ambulance vehicle. All material used in this unit is easily available, so it commercially adopted in automotive mini trailer manufacturer. Also it has less complexity and economically advantageous for middle class farmer.

Investigation on different Compositions of E-Glass/Epoxy Composite and its application in Leaf Spring

The unique and diverse characteristics of composite materials have increased in many folds. From feather weight rods to high performance aircraft parts, the use fiber reinforced materials have become a compelling asset due to their high strength to weight ratio and high strength to stiffness ratio combined with easy manufacturing methods. The present endeavor is one such attempt to study the mechanical properties of glass fiber reinforced plastic (GFRP) by varying volume percentage. The mechanical properties involved in the study are tensile strength, bending strength and impact strength. The results are compared for different loading conditions and a suitable composition is selected for the fabrication of mono composite leaf spring. The study concluded that the composite leaf spring had induced stresses much lower than that of steel leaf spring and the spring weight was nearly 44% lower when compared to steel leaf spring.

Design and Analysis of Automotive Multi-Leaf Springs Using Composite Materials

One of the oldest suspension components that are still in use, especially in commercial vehicles, is leaf springs. Due to high strength to weight ratio, the automobile industries have shown interest in replacing steel springs with composite leaf springs. This work is carried out on multi leaf springs having nine leaves, used in commercial vehicle. A Finite element approach for analysis of a multi leaf springs using ANSYS software is carried out. The model is generated using solid works and imported in ANSYS. The material of the leaf springs is 65Si7 (SUP9), composite leaf springs and hybrid leaf springs. Fatigue analysis of leaf springs is carried out for steel leaf springs, and Static analysis for steel leaf springs, composite leaf springs and hybrid leaf springs.

EXPERIMENTAL INVESTIGATION OF FIBERGLASS REINFORCED MONO-COMPOSITE LEAF SPRING

The Automotive industry has witnessed major growth in use of fiberglass reinforced polymers. One such area of application is the composite leaf springs. Leaf springs are used in suspension systems for vehicles. Currently the ideal choice is the multiple laminated leaf steel springs. The aim is to compare a mono composite leaf spring with a steel leaf spring for different test conditions. Physical testing is carried out for two different samples 60% epoxy40% E-fibreglass and 50% epoxy - 50% E-fibreglass, both prepared in the laboratory. The study gives a comparative analysis between the composite leaf spring and steel leaf spring based on physical properties.

Analysis of Steel and Composite Leaf Spring for Vehicle

The Automobile Industry has shown keen interest for replacement of steel leaf spring with that of glass fiber composite leaf spring, since the composite material has high strength to weight ratio, good corrosion resistance and tailor-able properties. The present study searches the new material for leaf spring. In present study the material selected was glass fiber reinforced plastic (GFRP) and the polyester resin (NETPOL 1011) (5) is used against conventional steel. A spring with constant width and thickness was fabricated by hand lay-up technique which was very simple and economical. The numerical analysis is carried via finite element analysis using ANSYS software. Stresses, deflection and strain energy results for both steel and composite leaf spring material were obtained. Result shows that, the composite spring has maximum strain energy than steel leaf spring and weight of composite spring was nearly reduced up to 85% compared with steel material. This paper describes design and FEA analysis of composite leaf spring made of glass fibre reinforced polymer. The dimensions of an existing conventional steel leaf spring of a light commercial vehicle are taken for evaluation of results. I. Introduction Finite Element analysis tools offer the tremendous advantage of enabling design teams to consider virtually any molding option without incurring the expense associated with manufacturing and machine time. The Ability to try new designs or concepts on the computer gives the opportunity to eliminate problems before beginning production. Additionally, designers can quickly and easily determine the sensitivity of specific molding Parameters on the quality and production of the final part. The leaf spring model is created by modeling software like pro-E , Catia and it is imported in to the analysis software and the loading, boundary conditions are given to the imported model and result are evaluated by post processor. The different comparative results of steel leaf spring and composite leaf spring are obtained to predict the advantages of composite leaf spring for a vehicle. II. FEA (Finite Element Analysis) FEA tool is the mathematical idealization of real system. Is a computer based method that breaks geometry into element and link a series of equation to each, which are then solved simultaneously to evaluate the behavior of the entire system. It is useful for problem with complicated geometry, loading, and material properties where exact analytical solution are difficult to obtain. Most often used for structural, thermal, fluid analysis, but widely applicable for other type of analysis and simulation

Performance Comparative Analysis of S-Glass Epoxy Composite Leaf Spring with Mild Steel Leaf Spring

Performance Comparative Analysis of S-Glass Epoxy Composite Leaf Spring with Mild Steel Leaf Spring

Design and Analysis of Composite Leaf Spring

In these paper, composite structures for conventional metallic structures has many advantages because of higher specific stiffness and strength of composite materials is discussed. The automobile industry has shown increased interest in the replacement of steel spring with fiberglass composite leaf spring due to high strength to weight ratio. This work deals with the replacement of conventional steel leaf spring with a Mono Composite leaf spring using E-Glass/Epoxy. The design parameters were selected and analyzed with the objective of minimizing weight of the composite leaf spring as compar

Finite element analysis on the static and fatigue characteristics of composite multi-leaf spring

This paper investigated the static and fatigue behaviors of steel and composite multi-leaf spring using the ANSYS V12 software. The dimensions of an existing conventional leaf spring of a light commercial vehicle were used. The same dimensions were used to design composite multi-leaf spring for the two materials, E-glass fiber/epoxy and E-glass fiber/vinyl ester, which are of great interest to the transportation industry. Main consideration was given to the effects of material composition and its fiber orientation on the static and fatigue behaviors of leaf spring. The design constraints were bending stresses, deflection and fatigue life. Compared to the steel leaf spring, the designed composite spring has much lower bending stresses and deflections and higher fatigue life cycles.

Modeling of Shot Peening Parameters for Weight Reduction of EN45A Spring Steel Leaf Springs

A lot of research has been done to improve the fatigue strength of materials by creating compressive residual stress field in their surface layers through the shot peening. In the present work, it is found that relaxed residual stress field varies with shot peening intensity and affects weight of EN 45A spring steel leaf springs. A stress approach model for weight reduction of leaf springs used in automotive vehicles has been experimentally developed simulating with industrial environment. Paper discusses a time saving and reliable method of predicting thickness and weight of leaf springs at various shot peening intensities for industrial applications. A model based on experimental results has been developed which predicts weight reduction of leaf springs for a given stress at varying shot peening conditions.

Testing of Fiber Composite Leaf Spring for Heavy Axle Loads

This paper presents the results of quasi-static and dynamic testing of glass fiber-reinforced polyester leaf suspension for rail freight vehicles named Euroleaf. The principal elements of the suspension’s design and manufacturing process are initially summarized. Comparison between quasi-static tests and finite element predictions are then presented. The Euroleaf suspension have been mounted on a tipper wagon and tested dynamically at tare and full load on a purpose-built shaker rig. A shaker rig dynamic testing methodology has been pioneered for rail vehicles, which follows closely road vehicle suspension dynamic testing methodology. The use and evaluation of this methodology have demonstrated that the Euroleaf suspension is dynamically much softer than steel suspensions even though it is statically much stiffer. As a consequence, the suspension dynamic loading at laden loading conditions is reduced compared to the most advanced steel leaf suspension over shaker rig track tests.

Inelastic deformations of stainless steel leaf springs-experiment and nonlinear analysis

A stainless steel leaf spring is designed and constructed followed by its performance evaluation by experiment and non-linear analysis so that an insight into the optimum use of material can be made. Cantilever beams of uniform strength, popularly termed as leaf springs, undergo much larger deflections in comparison to a beam of constant cross-section; that needs inclusions of geometric non-linearity for rigorous analysis. This study deals with such a cantilever beam, but takes into account the material non-linearity as well. Experiments were conducted for such a cantilever beam, with highly non-linear stress-strain curves. In addition to the experiment, a computer code in ‘C’ has been developed using the Runge-Kutta technique for the purpose of simulation. Effective modulus-curvature relations are obtained from the non-linear stress-strain relations for different sections of the beam and used for the analysis. It is seen that non-linear stress-strain curve governs the bending of the beam. Importantly, non-linear analysis shows the stresses are not so high as predicted by the linear theory without end-shortening. Moreover, the tensile and compressive stresses are different in magnitude and both decrease along the span. Experimental load-deflection curves are found to be initially concave upward but, non-linear and convex upward at a high load. Comparison of the numerical results with the available experimental results from another research group and theory shows excellent agreement verifying the soundness of the entire numerical simulation scheme.

Simulated annealing approach to the optimal design of automotive suspension systems

This paper presents an approach for the design optimisation of suspension springs, such as coil springs, torsion bar springs, steel leaf springs and composite leaf springs, using a Simulated Annealing algorithm. Around 14.39% of coil spring mass and 7.12% of torsion bar spring mass are reduced. In the case of steel leaf springs, 14.40% of mass, under two variables condition and 16.58% of mass, under three variables condition are reduced. Similarly, 22.93% of mass under two variables condition and 29.28% of mass under three variables condition are reduced in the optimisation process of composite leaf springs. When the composite leaf spring is compared with the conventional steel leaf spring, the mass reduction obtained before optimisation is 83.52% and mass reduction obtained after optimisation is 85.16% in the case of two variables condition and 86.03% in the case of three variables condition for the same load carrying capacity and stiffness.

Effect of surface roughness on the fretting fatigue behaviour of EN45A spring steel

Much research has been carried out to improve the fatigue strength of materials in general and leaf springs in particular by creating a compressive residual stress field of their surface layers through shot peening. The phenomenon of surface roughness is important when considering contact between metallic bodies. The effect of shot flowrate on surface roughness was identified. Full-scale laboratory testing of EN45A spring steel leaf springs was carried out using an electrohydraulic testing system to show the extent of improvement in fatigue life due to shot peening. Double shot peening was performed on leaf springs and its effects on surface roughness, compressive residual stress field, and fretting fatigue were noted. The surface roughness model is in accordance with the experimental results.

Investigation into the Effects of Shot Peening on the Fretting Fatigue Behaviour of 65Si7 Spring Steel Leaf Springs

Leaf springs are subjected to varying stresses and vibrations due to road conditions. The influence of high contact pressures and temperatures follow fretting fatigue between two mating leaf surfaces. The work presented in this paper relates to improvement in fatigue and fretting fatigue performance of leaf springs using shot peening and coatings. The fatigue life of 65Si7 spring steel leaf springs has been determined experimentally at various shot peening conditions and optimum shot peening intensity is found. Full-scale leaf spring laboratory testing and specimen testing were carried out to show the extent of improvement in fatigue life as a result of shot peening. Structural damping is found to be an important surface characteristic of shot peened surfaces for reducing fretting fatigue. The effects of shot peening conditions and damping factor for minimizing fretting fatigue failures are discussed.

Analysis and optimization of a composite leaf spring

A four-leaf steel spring used in the rear suspension system of light vehicles is analyzed using ANSYS V5.4 software. The finite element results showing stresses and deflections verified the existing analytical and experimental solutions. Using the results of the steel leaf spring, a composite one made from fiberglass with epoxy resin is designed and optimized using ANSYS. Main consideration is given to the optimization of the spring geometry. The objective was to obtain a spring with minimum weight that is capable of carrying given static external forces without failure. The design constraints were stresses (Tsai–Wu failure criterion) and displacements. The results showed that an optimum spring width decreases hyperbolically and the thickness increases linearly from the spring eyes towards the axle seat. Compared to the steel spring, the optimized composite spring has stresses that are much lower, the natural frequency is higher and the spring weight without eye units is nearly 80% lower.