Papers by Keyword: Leaf Spring

Abstract: As a result of the high strength-to-weight ratio, the automobile industry is becoming increasingly interested in replacing steel springs with composite leaf springs. The task at hand is to swap out some steel springs for alloy springs. The car's suspension impacts how comfortable it is to drive and how much damage it sustains. The leaf spring group's primary role is to support the suspension element's vertical load. The contact between the blades makes adjusting the crossbow's action more difficult. The goal of this article is to replace steel multi-disc springs with single joint springs that have a higher load carrying capacity and are more stiff. This alloy offers a greater strength-to-weight ratio and a more elastic corrosion energy storage capacity than steel. The crossbow's weight can be lowered without sacrificing the crossbow's load capacity or stiffness. The stress and displacement are controlled by the barrier design.

Abstract: Conventional steel springs have gradually been replaced with composite materials due to their inherit properties like high strength-to-weight ratio, relatively inexpensive ratio, and resistance against corrosion. Also, fiberglass reinforced plastic usages and its implementation is subjected in variety of fields such as vehicle and locomotive bogies, heavy commercial vehicles like vans and trucks. The current study looks at a composite material that can be used in the composite leaf spring suspension system. In this particular research, several blends of interpenetrating polymer networks (IPNs) have been used as the matrix material with the reinforcement of E-Glass fiber. The implemented combination blends are epoxy with polyurethane (EP), vinyl ester with polyurethane (VP) and epoxy and vinyl ester (EV). However, this research work also examines the characterisation and physical properties of the composite material leaf spring (CMLS) in narrow manner. Consecutively, tests were carried out for three types of composites by varying the various blend ratios of IPNs with the standard reinforcement of E-Glass fiber. Besides, to evaluate and compare their individual uniqueness, their physical characteristics tests like compression test, hardness test, tension and cyclic load parameters are found and their corresponding results were compared with each other.

Abstract: 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, K_I = 29.15 MPa.m^1/2 was greater than the value of fracture toughness, K_IC = 23 MPa.m^1/2 of the spring material.

Abstract: Manufacturing of leaf spring for automotive application to support heavy load vehicles such lorry and truck is a challenging process. This is due to the difficulty in fabricating the leaf spring exactly as per designed. The difference between the desired leaf spring shape and the actual fabricated shape is known as camber drop. The aim of this study is to establish the correlation between leaf spring specifications, camber drop and its processing parameters. The formulated equation can thus be used to predict the extent of camber drop and required action can be taken to reduce camber drop. This work was conducted by gathering data of variables suspected to influence camber drop, namely quenching camber, half-length of the spring, spring rate and end thickness of the spring. Regression analysis was conducted and the correlation between leaf spring’s specifications and camber drop is given. A mathematical model able to predict the extent of camber drop is formulated.

Abstract: Parabolic leaf spring is a suspension component for heavy vehicles where spring itself experiences repeated cyclic loading under operating condition. Fatigue life of the parabolic leaf spring is vital since the deflection of the spring is large and continuous. To determine the fatigue life of the parabolic leaf spring, material properties input to the design is important. The objective of this study is to predict the fatigue life of a parabolic leaf spring based on two different material grades which are SAE 5160 and SAE 51B60H under constant amplitude loading through various mean stress method. SAE 51B60H is the material with slightly higher carbon, manganese and chromium content compared to material SAE 5160. Chemical composition differences between SAE 5160 and SAE 51B60H have significant effects on the mechanical properties and fatigue life. In this analysis, finite element method together with multi mean curve stress life (S-N) approach has been implemented to estimate the fatigue life of the spring. Goodman, Gerber and Interpolate mean stress correction method were adopted to correct the damage calculation for mean stress. The results show that interpolate and Goodman method predict the fatigue life of the material with higher accuracy. On the other hand, material SAE 51B60H yields higher fatigue life compared to material SAE 5160.

Abstract: The traditional design method of heavy truck leaf spring is always the trial-and-error method. In addressing the problem of being multi-objective, the weakness is that there is a large amount of calculation and it is difficult to find the most optimal solution. The leaf spring of the sinotruck ZZ4256N324MD1B is taken as the research object. With the constraint conditions of the spring's overall layout, stiffness, strength, material, size, and the requirements of the manufacturing process, the optimization design model is established. We follow the method of particle swarm optimization algorithm to get the more optimization design on the leaf spring. The calculation of design example shows that the method this article uses of optimization to solve practical engineering problems with complicated constraints is very effective.

Abstract: Aiming at the processing problem of electric bus leaf spring equivalent model, the amendment leaf spring equivalent processing model is proposed after 3 kind leaf spring equivalent models are studied. This paper makes a comparison between the amendment leaf spring equivalent model and other models. Results show that the amendment leaf spring equivalent model not only considers the longitudinal force and lateral force of the leaf spring, but also avoids emergence the high stress area. So the amendment leaf spring equivalent model is more conform to the actual force situation of the electric bus frame, and it can provide the reliable constraint conditions for the next electric bus lightweight.

Abstract: In the paper, use the finite element software to simulate the loading of a car's rear leaf spring in the actual test, analyze the stiffness and free camber of a leaf spring, compare with the data of experiment. which fully approved that this theory can be applied to the analysis of a leaf spring's actual exploitation and design. At the same time, extract the displacement of the lug and rear axle point, analyze its trajectory based on the multi-body dynamics. It offered reference for design and development of the same types of leaf springs in the early period. Keywords: Leaf spring Finite element Stiffness characteristics Free camber

Abstract: The automobile industry has shown an increased interest in the use of composite leaf springs due to their high strength to weight ratio. The introduction of composite materials has made it possible to reduce the weight of the leaf spring without any reduction in load carrying capacity and stiffness. In this paper, the results of research on fatigue life of composite (Glass Fiber Reinforced plastic – GFRP) leaf springs are presented. Composite springs were designed in such a way that they could replace steel springs in a van.

Abstract: Overloading the impact on traffic safety, measuring the deformation of leaf spring form the start, a vehicle load measuring system was designed based on ultrasonic sensors. In this article, the mathematics model of steel plate deformation and load is discussed upon the mechanics principle and obtain the relationship of load and deformation. Processing the data that the ultrasonic sensors measured by single-chip and using temperature sensor to compensate, it comes to the result of vehicle load.According to the test, the system achieved the purpose of real time measurement of vehicle load, and it is useful.