Design, analysis and optimization of a composite leaf spring for light vehicles

Characterization and Investigation of Mechanical Properties of Composite Materials used for Leaf Spring

Composite leaf springs constructed of glass fiber reinforced polymeric materials have been recognized as viable replacements for steel springs. Experience gained in the use of composite leaf springs in passenger vehicles is encouraging and clearly demonstrates the utility of glass fiber reinforced composites for leaf spring applications. This paper dis cusses a study on the use of glass fiber reinforced composite leaf springs for commercial vehicles, particularly for heavy tank trailer suspension systems. A general discussion on the analysis and design of constant width, variable thickness composite springs is pre sented. An example is given for the design of a composite spring for one of a tank trailer fleet. This spring is three inches wide with a maximum thickness of about two inches. Several dozen springs were fabricated according to the design and road tested on tank trailers. In general, the road test results demonstrated the applicability of glass fiber rein forced composite springs for trailer suspensions. The composite leaf springs were well received by the trailer operators.

Analysis of laminated plain carbon steel leaf spring in maxi truck

Suspension systems are automotive parts whichabsorb sudden impacts caused by roads and providing comfort have an essentialrole in the automotive sector. Reducing weight is a fundamental way to decreaseenergy consumption and emission release. This study establishes improvementconditions by analysing layered composite springs which have differentcompositions and different support angles under various weights. Ten plaqueswhich made with various compositions chitosan and carbon nanotubes, alsoone-way glass fiber/epoxy composite plaques with prepreg method and oneunalloyed plaque were produced. Standard samples were extracted by water jetand pull&push test were applied to identify mechanical properties. Fivestandard samples were used to identify each mechanical property. Mechanicalproperties of samples with different compositions were compared.Identified mechanical properties were used asmaterial properties at the ANSYS ACP PRE&POST analysis program. Compositespring thicknes were 12 mm and it is composed of 60 layers. Static analysis ofcomposite springs modelled with five different layer orders was done byapplying 1000 N, 2000 N, 3000 N and 3750 N force. Collapse, stress and shapechanges of composite springs were examined at static analyses.Analysis show that unalloyed composite leafspring is more resistant than its counterparts. When Layer Order 1 (TD1) [0°)]60 with the same direction for fiber and horizontal axis of composite leafspring is compared with others, it is seen that composite spring with TD1 ismore rigid against bending. Damage analysis was done with ACP POST programaccording to Tsai-Wu and Hashin standards and it is seen that end points ofsprings were mostly damaged. Most damaged one is the TD5 leaf spring with [(0°5/90°5/45°10/-45°10)]slayer order under 3750 N according to Tsai-Wu standard. In addition tothat, composite leaf springs were %49,84 lighter than mostly used one leafsteel counterparts.

In the present scenario, strength of the structures has been the main focus of automobile manufacturers. The suspension leaf spring is one of the potential items for higher strength in automobiles as it accounts more than two times stronger than the conventional steel leaf spring. This helps in achieving more damping capacity, less fuel consumption and resistance against impact loads in the vehicle. The introduction of composite materials made it possible to avoid catastrophic damage due to sudden impact loads that are transferred to the chassis of light passenger vehicle through the leaf spring. In this work, an attempt has been made in replacing the design of a conventional multileaf leaf spring by a composite multileaf leaf spring based on strength ratio without any modification of the existing design of a light passenger vehicle. The materials adopted in the analysis of composite multileaf leaf spring are glass/epoxy, glass jute /epoxy, carbon jute/epoxy. The optimum material combination is determined based on the maximum induced bending stress, material availability and the contact pressure generated between each and every laminate which will influence the unsprung weight of the light passenger vehicle. Due to impact loads acting on the multileaf leaf spring damage tolerance work is also carried out in the composite material that has minimum contact pressure by creating artificial hemispherical damage for varying proportions. The optimum composite multileaf leaf spring is fabricated using filament winding technique. Modeling and contact analysis were carried out for both conventional and composite materials using ANSYS 8.1 software. From the investigations undergone, it is well proved that composite multileaf leaf spring made of glass/epoxy is found to be of higher strength comparing strength ratio, induced bending stress, contact pressure as well as with respect to cost, than the conventional leaf spring and the optimum damage radius due to sudden impact loads is also predicted in the composite multileaf leaf spring.

Article history: Received October 6, 2014 Accepted 2 February 2015 Available online 2 February 2015 Parabolic leaf spring is one of the vital components in vehicle suspension system, and it is commonly used in heavy vehicles. It needs to have an excellent static load bearing capacity and fatigue life too. The purpose of this work is to make computer aided engineering (CAE) analysis of mono parabolic leaf spring and to see the effect of change of material in the optimized leaf. A mono steel leaf spring and a mono leaf spring made of composite material have been selected for this comparative analysis. The material of the mono steel leaf spring is EN45A and Glass Reinforced Plastic (GRP) as composite material which is having high strength to weight ratio. The mono leaf spring model is having one full length leave with eyes at both ends, two pins in each eye end and a rubber pad on the upper face of leave center. The CAD modelling of parabolic leaf spring has been done in CATIA and for analysis the model is imported in ANSYS workbench. It was shown that the use of composite material instead of steel resulted into large deflection, small variation in stresses and also a large amount of weight reduction. © 2015 Growing Science Ltd. All rights reserved.

Conventional materials used for an automotive suspension system are one of the key parameters which influence the vehicle weight. Hence the use of composite material for suspension system would offer a significant benefit of being light in weight also have a high life span compared to existing materials, without compromising the load-carrying capacity and stiffness. The primary emphasis of this paper is on gaining a finite element-based performance analysis of advanced composite materials as a substitute for conventional materials used for the application of leaf spring suspension of an automobile. The leaf springs were modeled using CATIA, to replace the existing material of steel alloy and carbon alloy leaf springs with a composite material (Carbon Fiber-reinforced polymer) for a pickup truck and Finite Element Analysis (FEA) was performed using ANSYS for static load condition and the results were compared with conventional leaf spring materials to determine the structural characteristics. Furthermore, vibrational characteristics were also presented by modal analysis for the designed leaf springs. It was inferred from the results that advanced composite materials are light in weight, optimal, and ideal material for the leaf spring offering better structural & mechanical behavior.KeywordsANSYSCATIAComposite materialsFinite Element AnalysisLeaf springsNatural frequencyStatic analysis

Design and analysis of composite mono leaf spring for passenger cars

A leaf spring is a suspension spring, commonly used to absorb the vibrationsbrought during themotion ofa vehicle due to load or road condition. The automobile sector has shown an improved concern in the replacement of metal leaf spring with composite materials due to extraordinary strength to weight ratio. This article is based on the performance comparison of leaf spring prepared from composite material which can be suitable for automobiles. By using composite fibers determinations have been made to reduce the cost and mass of the leaf spring. The composite material used here is an aramid fiber which known for its high tensile strength, high heat resistance, less abrasive and reduced weight ratio. The leaf spring is designed and analyzed. The specimens were fabricated as per the ASTM standards and testing was carried out.

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.

Views Icon Views Article contents Figures & tables Video Audio Supplementary Data Peer Review Share Icon Share Twitter Facebook Reddit LinkedIn Tools Icon Tools Reprints and Permissions Cite Icon Cite Search Site Citation A. Imthiyas, Samuvel Michael B., Naveen R., M. Arun Murugan, Mukesh Dinesh; Analysis of conventional and composite leaf spring using ANSYS. AIP Conference Proceedings 30 January 2023; 2523 (1): 020166. https://doi.org/10.1063/5.0112445 Download citation file: Ris (Zotero) Reference Manager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex toolbar search Search Dropdown Menu toolbar search search input Search input auto suggest filter your search All ContentAIP Publishing PortfolioAIP Conference Proceedings Search Advanced Search |Citation Search

The taper leaf spring of tandem suspension of commercial vehicle is different from the traditional taper leaf spring. Thus, the professional software MSC.ADAMS/CHASSIS leaf spring, which is specially applied in traditional leaf spring, does not reliably develop the computational model of the taper leaf spring of tandem suspension. The multi-body dynamic model of the taper leaf spring of tandem suspension, which is developed in this paper, is a secondary development model that is based on the leaf spring model built by MSC.ADAMS/CHASSIS leaf spring. End contact and friction in the modified model are redefined to exhibit the hysteretic characteristics of the taper leaf spring of tandem suspension. The test of the taper leaf spring of tandem suspension is conducted to validate the reliability of the modified model. The tests in this paper are divided into two groups. The first group started at an unloaded state at an excitation frequency of 1/30 Hz and amplitude of 70 mm to acquire quasi-static behavior. The second group is conducted at various frequencies (2, 3 and 4 Hz) and various amplitudes (±1, ±3 and ±10 mm) in a loaded state to acquire dynamic behavior. A formula to calculate dynamic spring rate for leaf spring is proposed, and details about the formula are presented. The simulations are conducted under the same conditions as the test. The hysteretic characteristics and the relative error of dynamic spring rate from the test are compared with the ones from the simulations for the validation of the reliability of the modified model.

The amount of vehicle damage and ride comfort of the passengers is mainly determined by suspension system which plays a major role in automotive vehicle dynamics. Leaf springs are found to be durable and inexpensive. They are good at isolating road incited vibrations and support vertically acting loads. This is the reason that the static and dynamic examination of the leaf spring is exceptionally fundamental to anticipate the quality and vibration properties. Stacking sheets of metal having extensive thickness of various lengths are arranged in a manner by which the more extended leaves are on the top of the shorter leaves banding them together with the assistance of a centre bolt, two U braces and four rebound clips which frames a leaf spring. The behavior of leaf spring is complicated because of its effects caused by the clamps and contact between the leaves. It is inferred from literature that, for the suspension arrangement of the passenger vehicles the excitation frequencies range from 1Hz to 800 Hz because of road irregularities which have to be damped to prevent passenger discomfort. This research work predominantly focuses on the static and modal examination to discover the mode shapes and their individual natural frequencies and validated by the experimental results with the assistance of LMS Test Lab. The modal analysis is done with the same three-dimensional model leaf spring of Maruti Suzuki Omni passenger vehicle using FEA. The design optimization is performed based on finite element analysis which helps in weight reduction by maintaining similar modal behavior and strength. Consequently, the natural behavior of leaf spring is investigated up to 10 mode shapes. The actual behavior of the leaf spring under road irregularities is recreated by road testing. The results obtained are analyzed and compared with standards and suitable damping is suggested to control vibrations.

Leaf springs are designed to dampen the vibrations caused by different loadings such as lateral loads, shock loads, and torsion. The important role of this component in a vehicle makes its failure cause serious accidents. Therefore, this study aimed to determine the cause of leaf spring failure in the 110 PS dump truck vehicle suspension system. An experimental approach was adopted and this involved the visual and fractographic observation of the fracture surface, hardness test, chemical composition test, microstructure evaluation, and analysis to determine the magnitude of the stress intensity factor. The results of observations showed the presence of a chevron pattern indicating an initial crack in the leaf spring followed by a beach mark pattern which is evidence of repeated loading. Moreover, a smooth flat part in the fracture surface was discovered to be the final fracture zone while the values obtained from the hardness test were found to be more than the standard required. This spring fracture was also observed to have been caused by the fact that the truck carried a load which exceeds its carrying capacity. The stress intensity factor analysis produced KI values which are very close to the fracture toughness KIC value of the spring material and this caused the crack propagation to fracture. The failure in the leaf spring was caused by an initial defect observed on the inside of the hole in the spring. Moreover, the dynamic loads carried by the spring acting as a suppression system caused the initial crack followed by the crack propagation and the final fracture.

Leaf springs are crucial suspension elements in automobile, necessary to minimize the vertical vibrations, impacts and bumps due to road irregularities. The functions of the suspension springs for an automobile are to maintain a good control stability and to improve riding comfort. In other to meet the requirements of natural resource conservation and energy economy, automobile manufacturers have been attempting to reduce the weight of vehicles in recent years. The research reviewed the automotive leaf spring in it entirety as well as the used of CES EduPack 2011 software to justify the conventional material used for leaf spring. The paper also analyse an indebt configuration and methodologies that enable the researcher to select an alternate and advanced composite material suitable for leaf spring using the Cambridge Educational Software (CES) in other to meet the global glamour for automotive weight reduction, conservation of natural resources and energy minimization as been focus by automobile manufacturers in the present state.