Composite Leaf Spring Research Articles

Analysis of the deformation of conical shells made by 4D Printing of composites

4D printing of composites (4DPC) is a technique that allows the manufacturing of composite structures to shape without the use of a complex-shaped mold. Instead, only a flat mold is utilized. This innovative technique has been employed to make composite leaf springs with performance comparable to metallic springs, omega stiffeners, and corrugated core for flexible wings. Recently, this technique was applied to fabricate composite conical shells. While experimental work has successfully demonstrated the transformation from flat to conical shape, the development of a numerical method to replicate this transformation is highly desirable. The availability of such method not only provides theoretical support for the experimental result, it also provides means to develop other shapes. The lay-up sequence for transforming flat to conical shapes involves curvilinear fibers. Most if not all finite elements currently available deal only with straight fibers (even though the boundaries of the element may be curved). The objective of this research is to examine the efficiency of the analysis for the deformation of composite from flat to curve made by 4DPC by special finite elements containing curved fibers. The developed finite elements were used to determine the shapes of conical shells made using multiple distinct lay-up sequences. The direction of bending in curvilinear fiber structures is significantly influenced by the orientation of the fibers. This highlights the critical role of fiber orientation and layer composition in achieving desired shapes in 4D printed composites.

Study of Composite Light Weight Leaf Spring

The fundamental Objective of this project is to represent plan and exploratory examination of composite leaf spring made of glass fiber reinforced polymer. The intention is to look at the load carrying capacity, weight and stiffness effective of composite leaf spring with that of steel leaf spring. The design imperatives are stresses and deflections. The measurements of a current ordinary steel leaf spring of a light business vehicle are taken. Static investigation of leaf spring is likew ise performed utilizing analysis software and compared with experimental results. Limited component investigation with full load on 3D model of composite multi leaf spring is done utilizing analysis software and the analytical results are compared with experimentalresult

Fatigue Analysis of Composite Leaf Springs - A Review

The purpose of this paper is to provide a review of work that has been carried out in analyzing composite leaf springs. Leaf springs made of fibre reinforced composites exhibit much more advantages when compared with steel leaf springs. Most importantly, polymer composites increase the performances of vehicles by decreasing the weight of the leaf spring and also by providing corrosion resistance. This paper summarizes the fatigue analysis of composite leaf springs by considering the results obtained by some of the research works.

Analysis of glass fiber-reinforced composite leaf springs in a light commercial vehicle

Leaf springs are designed to bear loads as well as shocks in automotive vehicles. Two leaves of glass fiber-reinforced composites (GFRCs) of various shapes sandwiched between steel plates were analyzed for application in a minitruck. Computer-aided engineering analysis was performed for five different types of GFRC material leaf springs: flat leaf, flat and parabolic leaf, both parabolic leaf, both parabolic leaf springs with aluminium alloy bushes at the eye-end and spring steel multi-leaf springs. A silencer pad was used in the parabolic leaf spring to reduce delamination and vibration at contact points of the mating leaf. The various shapes and combinations of leaves provided varying parameters, namely, the deformation, maximum equivalent strain, maximum equivalent stress and fatigue life. The CAE results showed that compared with the other combinations, the flat leaf and parabolic leaf combinations provided the maximum equivalent strain, maximum equivalent stress and fatigue life.

Finite element design analysis of composite leaf spring

Finite element design analysis of composite leaf spring

Comparative analysis of static and vibration characteristics of glass fiber reinforced epoxy mono composite leaf spring and conventional steel leaf spring

Leaf springs play a vital role in heavy-duty vehicles by offering substantial load support, durability, and convenient maintenance. Lightweight leaf springs enhance vehicle performance, offering benefits like improved fuel efficiency and a smoother ride. Glass fiber reinforced composites enhance fuel efficiency and durability, providing corrosion resistance. Their design flexibility improves ride comfort, and damping properties enhance vehicle stability. The examination conducted through finite element analysis, utilizing ANSYS software, demonstrated a substantial 75.32% decrease in weight for the E-Glass-Epoxy composite leaf spring (GECLS), affirming its efficacy in enhancing strength, reducing weight, and enhancing stiffness. This underscores its superiority as a viable alternative to traditional steel leaf springs (SLS) in vehicular applications. The mono-GECLS exhibited a natural frequency that was found to be 1.9 times higher than that observed in the traditional SLS. It indicates the potential to mitigate resonance issues. After analysing the SLS and GECLS using ANSYS, it was observed that the GECLS exhibits greater values in deflection, natural frequency, and strain energy, measuring 4.659 mm, 29.98 Hz, and 440.68 mJ, respectively, compared to its steel counterpart. Conversely, the SLS demonstrates elevated values in stress, mass, and density, with readings of 283.84 MPa, 3.7695 kg, and 5920 kg/m³, respectively.

Analysis of Vibration in Hybrid Composite Leaf Spring

Vibration-related failures more frequently occur than material failures, analysis is crucial to the design of composite leaf springs. It must also have an outstanding fatigue life and be lightweight. To minimize vertical vibrations, hits, and bumps caused by irregular roads and to ensure a comfortable ride, springs are essential suspension components in automobiles. Hence, the material with the highest strength and lowest longitudinal elastic modulus is ideal for use in leaf springs. In the automotive business nowadays, composite materials primarily replace metal elements. Consequently, it is important to use a hybrid composite leaf spring that evenly distributes graphite, carbon, and glass fibers throughout the resin matrix and has a lower spring rate. Hybrid composite materials offer many advantages over conventional composite materials because they use glass and carbon fibers instead of them. These advantages include maximum strength, minimum longitudinal modulus of elasticity, reduced weight as well as vibration, better packaging, enhanced durability, cost savings, fatigue life, and strain energy capacity. The first use of modal analysis is to determine Eigen-vectors, or mode shapes, and Eigen-values, or natural frequencies. Moreover, random vibration analysis is used to distinguish between smooth and rough vibrations, and harmonic analysis is used to determine the response’s amplitude.

Designed and Analysed of Three Distinct Composite Material-Based Mano Leaf Spring using ANSYS

The leaf spring is an important component in vehicles because it provides a comfortable ride and stability to the vehicle. The need to replace leaf springs with stronger and more lasting leaf springs is a key challenge in the transportation and automotive industries. In addition to offering ride comfort and stability, traditional steel leaf springs have a significant impact on the weight of the car. Fibre reinforced polymeric composites, therefore, are appropriate materials for various applications due to their many exceptional properties, including high wear resistance, high strength, long fatigue life, corrosion resistance, and low density. Fiber-reinforced polymeric composites find extensive application in several technical sectors, such as automotive, aviation, military, and marine industries. The utilization of composite materials has become imperative in the automotive industry to attain weight reduction without compromising material strength, as fuel consumption and CO2 emissions have to be reduced. In this paper, three different types of composite-based mono leaf springs were designed and examined. The results of the investigations showed that the 0° unidirectional glass fiber system was unable to correctly produce the required spring rate. Consequently, many combinations of carbon and glass hybrid systems were studied. The analysis showed that the desired spring rate was produced by the material configuration of [0°6G / 0°2C / 0°22G] S. When the final results were contrasted with the FEA findings, it was found that they concurred.

Thermal fatigue analysis and structural optimization of sliding composite leaf spring

The thermal failure mechanism of sliding composite leaf springs (SCLSs) is examined in this research. Bench fatigue testing is used in the experimental investigation of the thermal failure temperature and mode. The findings demonstrate that after 20 min, when the temperature reaches the glass transition temperature, cracks start to form around the bolt hole of the composite body. The findings from bench experiments indicate that thermal fatigue failure of SCLS can be divided into three main forms: delamination failure of the resin-rich layer, the resin-fiber interface, and fibre pull-out failure. The utilization of finite element simulation has demonstrated that when subjected to thermal load, the leaf spring’s internal defects can lead to localized stress concentration. The structure of the spring end is optimized using the insulating panel scheme and the metal joint scheme. The thermal fatigue issue with SCLS is best addressed by the heat dissipation approach, according to bench tests.

Investigation on the effects of changing automotive vehicles leaf springs from steel to hybrid polymer composite leaf springs

Weight reduction is a critical factor in the vehicles and numerous researchers worked on better materials and design optimization to achieve that goal. This paper is focused to design a natural fibre reinforced hybrid polymer composite mono leaf parabolic spring to replace the existing steel multi-leaf semi-elliptical spring in an attempt of reducing the unsprung mass and to investigate its characteristics. The spring so designed is analyzed for its deflection and stiffness, by Virtual work method, whose complex integral was solved numerically by Gauss Quadrature. Along with this, SolidWorks was used to construct a model and ANSYS tests were used to compute the deflection, analyze the stress pattern and verify that the fail proof condition is met. Subsequently, three prototypes of the springs were fabricated by hand lay-up method. These springs were subjected to a static load test which results in deflection values similar to that of laminated steel springs with an appreciable 83 percent weight reduction. Modal Analysis conducted ensures that the fundamental frequencies of different modes are conveniently away from values of human discomfort and also from the nominal driving engine speed of 2000 rpm. The responses to harmonic disturbances which were studied experimentally, analytically and by ANSYS which indicates that vibration amplitudes due to average road undulations are under control, limiting the amplitude within 12 mm. The newly designed spring shall be recommended as a potential replacement, which can further be augmented by future works to be carried out on pot holes and studying the force transmitted on to the vehicle.

Design and Analysis of Leaf Springs with Structural Steel and Chromium Vanadium Steel

Abstract: Leaf springs are part of the suspension system on most vehicles and add weight to vehicles due to the traditional steel material. The automotive industry is interested in replacing traditional materials such as steel with other materials for various reasons, such as different mechanical properties. Intensive research is being carried out into replacing the leaf spring with a composite material. The composite material meets various test requirements of automotive standard due to its good elastic properties, high strength-to-weight ratio and lighter weight than steel. The purpose of the article is to focus on various topics such as weight, stresses during construction, modelling and experimental testing of composite leaf springs. In this work, the stress and deflection analysis of the leaf spring is calculated using the finite element method. Leaf springs are analyzed for stress and deflection in ANSYS 14.5. The results show, based on various calculations and observed data that with similar load capacities, induced stresses and deformations are minimized by replacing the steel leaf springs with fibre composite leaves. The analysis was performed considering the leaf spring engine model with the same dimension geometry to reduce the leaf spring weight. A composite material is chosen for the leaf spring. The analysis was performed on the ANSYS 14.5 spring with the same load condition as the steel and composite leaf springs in terms of strength and weight. From the static analysis and test results, after the design change and stress analysis, the composite leaf springs were minimized by about 71.73% and the stress was reduced by 50-80%.

Structural Design and Analysis of Sliding Composite Mono Leaf Spring

<div>The lightweight structure of a semitrailer composite leaf spring is designed and manufactured using glass fiber composite to replace the conventional steel leaf spring. The sliding composite mono leaf spring was designed based on the conventional parabolic spring design theory. The composites product design (CPD) module of CATIA software is used to create the lamination of the composite leaf spring. Using finite element analysis of the position and proportion of ±45° biaxial layer by OptiStruct software, it is found that a certain proportion (nearly 5%) of a ±45° biaxial layer can effectively reduce the shear stress under the condition of keeping the total number of layers fixed. Then, the natural frequency, stiffness, and strength of the composite leaf spring are simulated by the finite element method. Finally, the stiffness, fatigue, and matching of the designed spring are tested by experiments. The design weight of the composite leaf spring is 18.5 kg, which is 55.4% lighter than the conventional steel leaf spring. The composite mono leaf spring has good fatigue performance; the vertical fatigue cycles are more than 300,000 times, 1.6 times of the traditional steel leaf spring. The results of the system bench test show that the movement state of the composite mono leaf spring is consistent with the steel leaf spring. It can be preliminarily speculated that the composite leaf spring structure can meet the requirement of vehicles. A proposed method combining theoretical analysis, calculation, and finite element simulation can be used to design and test composite products quickly. This method has a high significance for the structural optimization of other laminated composite products.</div>

Design, Analysis and Optimization of a Lightweight Vehicle's Leaf Springs

In recent years, the automobile industry has primarily concentrated on reducing weight and improving ride quality. Because composite materials have a high strength-to-weight ratio, strong corrosion-resistance, and tailorable qualities, Steel leaf springs are being phased out in favour of composite leaf springs in the automotive industry. Three strategies have been investigated to reduce vehicle weight: rationalizing the body structure, using lightweight materials for parts, and reducing vehicle size. This study describes the static and dynamic analysis of steel 55Si2Mn90 parabolic leaf springs as well as composite parabolic leaf springs consisting of E Glass fibre, Carbon fibre, and Kevlar fibre. The goal of this study is to examine the load-carrying capability, stiffness, and weight reduction of composite and steel leaf springs. Dimensions of an existing steel 55Si2Mn90 parabolic leaf spring and a light commercial vehicle's composite parabolic leaf spring are taken. In terms of weight and stress developed, a comparison was made between composite and steel leaf springs. The Kevlar fiber leaf spring, after optimization, is 45.67% lower in weight than other materials and has superior riding quality than a typical steel spring with equal design criteria.

Design and Analysis of Steel Leaf Spring and Composite Leaf Spring using Finite Element Method Approach

Abstract: The leaf spring's purpose is to stabilize the vehicle because it’s an essentially required element for the suspension systems and assists in supporting the entire load on the vehicle. Hence, the design and analysis of leaf springs are the main focus of this study. To that aim, the CATIA V5 software is used to construct the model, and Ansys Workbench is used to perform static structural analysis. First, the solution is verified using the analytical method and the finite element analysis for structural steel, and then the static structural analysis of structural steel and composite material (CFRP) is compared for the same design. Here, we find that the deformation and stress values of the Composite material are less than that of structural steel.

A statistical approach to predict fatigue failure of leaf springs manufactured with nanotube incorporated epoxy‐woven glass fiber composites

AbstractIn this study, a statistical approach was developed to predict fatigue failure of laminated composite leaf springs prepared with carbon nanotube (CNT) filled epoxy/woven glass fibers. Electrical resistance change method and the Weibull analysis were adopted to develop a statistical approach. The electrical conductivity for successful application of health monitoring of leaf springs was achieved by dispersing 0.4 wt% of CNTs into epoxy resin. In‐situ monitoring of damage in composite leaf springs during fatigue tests applied as cyclic flexural deflection was carried out at nine different displacement ratios. The critical fatigue cycle and the corresponding change in electrical resistance were determined at each displacement ratio. Then, the critical electrical resistance change to cyclic fatigue was found 0.15% with 95% reliability by the Weibull analysis. The average fatigue life and the average strength loss corresponding to the 0.15% resistance change ratio were found to be 48.33% and 9.88%, respectively. The reported statistical concept based on the monitoring of change in electrical resistance during deflection can be successfully employed as a useful tool to predict safety limits of composite structures subjected to fatigue loading, especially in aerospace industry.

Suspension behaviour of kenaf and hemp fibre composites leaf spring using finite element analysis

In this study, the suspension behaviour of Kenaf and Hemp reinforced Epoxy composites leaf springs were evaluated and compared to that of steel and synthetic fibre composites leaf spring. The analysis to investigate the bio-composites performance under static and dynamic loads was carried out using the finite element ANSYS software. The results showed that both natural composite leaf springs having approximately 50 times the deformation, strain energy, and similar stresses as structural steel, and a weight reduction of 83.1 %. The dynamic analysis revealed that the first natural frequencies of the Kenaf and Hemp fibre reinforced epoxy composites leaf springs were higher than the typical road irregularity frequency. The natural frequency of bio-composites leaf springs is 18.506 Hz for kenaf fiber/epoxy composites and 18.502 Hz for hemp fiber/epoxy composites, which is approximately 54 % higher than the frequency of road irregularities of 12 Hz.

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

Leaf spring is the most widely used suspension system in automobiles which is subjected to various types of stresses and deflection. Generally, steel is used as a material for the leaf spring but steel is having high density due to which its weight is also more. There is a lot of scopes to replace the steel with other material to reduce the total weight of the vehicle. The advancement in plastic-reinforced fibre is useful for decreasing the weight of the component the composite materials are having high strength and low weight as compared to steel. In this proposed work composite material is used in place of conventional steel. The composite material is made up of glass and fibre called Epoxy resin. Various test is performed to carry out the properties of the composite material. Ant colony optimization approach is used to design and optimization of composite leaf springs. A geometric model of the leaf spring is prepared in the CATIA V5 software and analysis is done. It is found that composite springs can sustain the load the same as that of the steel leaf spring, and less deflection is observed in composite springs than in steel leaf springs. The density of the composite material is low so eventually, weight is also reduced by 70 % to 80%.

A New Composite Leaf Spring for In-Board Bogie of New Generation High-Speed Trains

A New Composite Leaf Spring for In-Board Bogie of New Generation High-Speed Trains

Innovative design steps towards a safe active lightweight chassis for an electric vehicle

Lightweight design is still very important for an all-electric vehicle especially when used in urban areas. A new active chassis suspension designed for such an urban car is in development at the DLR. The first main component is a composite transverse leaf spring, where a new (partly) automated design and dimensioning process is in development. The second component is an orbital wheel bearing with an optional integrated electrical drive. The third component is an innovative wheel independent two axis steering actuator changing the toe and camber angle. This enables an increase of the active and passive safety of the occupants. First simulations proved the benefits of the concept regarding enhanced crashworthiness. The modular concept of the system allows to use the same wheel at each corner of the vehicle without changing a single part, thus reducing vehicle part variants and costs.

Static analysis on mono composite leaf spring for Maruti 800 light vehicles

In this paper design and analysis of composite leaf spring made of glassfiber reinforced polymer (GFRP) and sisal fiber reinforced polymer (SFRP). In addition, to compare the load carrying capacity, stiffness and weight savings of composite leaf spring with that of steel leaf spring. The dimensions of conventional steel leaf spring are used to fabricate a composite mono leaf spring using GFRP unidirectional laminates. Static analysis of 2-D model of conventional leaf spring is also performed using Finite Element Analysis (FEA) and compared with experimental results. and the analytical results are compared with experimental results from the analysis it is observed that Sisal fiber /Epoxy mono composite leaf spring showing best results as compared to the other materials