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Investigation on the feasibility of composite coil spring for automotive applications
Abstract
This paper demonstrates the feasibility of replacing the metal coil spring with the composite coil spring. Three different types of springs were made using glass fiber, carbon fiber and combination of glass fiber and carbon fiber. The objective of the study is to reduce the weight of the spring. According to the experimental results the spring rate of the carbon fiber spring is 34% more than the glass fiber spring and 45% more than the glass fiber/carbon fiber spring. The weight of the carbon fiber spring is 18% less than the glass fiber spring, 15% less than the Glass fiber/carbon fiber spring and 80% less than the steel spring.
... Then, substituting Equations (7), (10), (18) and (19) into Equation (32), it is possible to have ...
... Even today, Wahl's work is still used by many scholars and helical structure manufacturers. With the aid of Wahl model[16], Mehdi et al.[17] and Budan et al.[18] respectively analyzed compressive behaviours of three different fiber reinforced CHS. The results showed that the weight and stiffness of helical structures can be effectively optimized by changing the type of material. ...
... In this discussion, any reference to shock absorbers will also apply to struts. The figure 1 shows the composite spring which we manufactured [2]. ...
... If the ride height of a vehicle has decreased excessively or a coil/leaf has broken it is advisable to replace the springs in axle sets. Consumers also often change springs to alter their vehicle's ride and handling characteristics [2]. Spring problems are generally easy to identify. ...
This work deals with learning the latest trends in automobile sector and improvement in materials for Shock absorbers which are nothing but the suspensions and the objective is to compare these suspensions made on composite materials with the mono suspensions in vehicles and to determine their improvisation and performance. Various tests are done and their results are observed under tabulation. The resultant graphs are obtained from MANUAL TESTING in Bangalore and their performances are compared. It is proved that the suspensions made by composite materials are stronger than other conventional materials. These advanced components play a vital role to protect the automotive from sudden impacts and shocks. Hence, materials of suspensions should be strong and therefore composite materials are encouraged as they are both strong and light weight. The results are calculated by design data with calculations being done and graphs drawn to obtain the optimum values.
... Te study shows that shear stress decreases as the fber angle changes, and it reaches its lowest value when the fber's position is perpendicular to the load [52]. Similarly, Budan and Manjunatha [53] investigated that the conventional steel coil spring can be replaced by a composite coil spring to reduce the weight. Te study uses three springs of glass fber, carbon fber, and a combination of glass fber and carbon fber. ...
The quest for lightweight, efficient, and corrosion-resistant coil springs for vehicle suspension systems has led to the exploration of alternative materials beyond traditional steel. This study delves into the potential of composite materials, particularly carbon/epoxy and carbon/carbon nanotube/epoxy, as replacements for conventional steel coil springs in light vehicles. Through a comprehensive analysis of mechanical properties under static and dynamic loading conditions, the study demonstrates the superior performance of composite springs compared to their steel counterparts. After optimization, the deflection of the carbon/carbon nanotube/epoxy and carbon/epoxy springs decreased to 15.003 mm and 18.703 mm, respectively, and the maximum shear stress decreased by 64.63% and 62.2%, respectively. Likewise, strain energies increased to 2.3644 and 3.5616, respectively. The springs were also studied under dynamic conditions, and the result showed these springs have the ability to perform in dynamic conditions. The carbon/carbon nanotube/epoxy composite emerged as the frontrunner, exhibiting remarkable improvements in shear stress, fatigue life, strain energy, and deformation properties. The study highlights the ability of carbon/carbon nanotube/epoxy composite springs to significantly reduce weight, enhance efficiency, and extend fatigue life, making them a promising alternative for next-generation vehicle suspension systems.
... Carbon under axial loading. (Budan and Manjunatha 2010) checked the possibility of changing from the metal coil spring to the composite coil spring. (Bakhshesh and Bakhshesh 2012) investigated the exchange of the steel coil spring with three different composite coil springs. ...
The main concern of companies is to increase productivity and efficiency with less resources usage and wastes. In this context, Lean Six Sigma ‘LSS’ is considered as the widely best used methodology to improve performance for a high efficient processes and has been adopted in manufacturing for several decades. Industry 4.0 ‘I4.0’ refers to various technology-driven changes in an organization’s manufacturing systems. The I4.0 related technologies are driving companies to a new level of operational excellence. The growing awareness of technological advances and the competitiveness of industries has resulted to an important transition in the way of thinking about optimization, costs reduction production and continuous improvement. The effect of Industry 4.0 on LSS is not well explored in literature. The present paper aims to address the related works and discussion on the interactions between the two approaches I4.0 and LSS based on literature review. The study is relevant to both scholars and practitioners by highlighting the ongoing challenges of implementing LSS in the Industry 4.0 era.KeywordsIndustry 4.0LeanSix sigmaLean six sigmaDigitalizationLiterature review
... Part of the literature investigates the feasibility of replacing metal helical springs with composite helical springs. It was found that by using a composite helical spring with a rubber core and a woven outer layer, the load capacity and stiffness of the helical spring were increased [5,6]. The related literature gives the results of stiffness and damping predictions using finite element methods on the basis of laminated, corrugated, metalpolymer composites. ...
Based on the stiffness theory of wave spring, this paper proposes the wave springs made of glass fiber reinforced plastic (GFRP) and investigates the effect of the number of periods on the GFRP wave springs’ stiffness and frequency response characteristics. First of all, five different periods of composite wave springs which have identical outside dimensions are designed. Afterwards, the load-displacement curves of the GFRP wave springs are obtained using a combination of experimental and finite element analysis (FEA). Finally, the frequency response characteristics of the GFRP wave springs are measured using a force hammer excitation, and the experiment results of a GFRP wave spring are compared with a metal helical spring. The results show that the stiffness of the GFRP wave spring decreases from 34.84 N/mm to 20.59 N/mm with the increase in the number of periods. As the number of periods increases, the vibration attenuation increases from 16.32 dB to 69.17 dB. The stiffness of the GFRP wave spring is increased by 90.30% and the weight is reduced by 26.78%. The vibration isolation interval and vibration attenuation amplitude of the GFRP wave spring are higher than the metal helical spring.
... Shock Absorber absorb the shock coming from tire and gives comfortable ride to the passenger (rider). [1][2][3][4][5][6][7][8][9][10][11][12]. Recently some investigations done on analytical modeling and optimal design of MR damper with power generation by Xiaocong etal. ...
A shock absorber suspension system of vehicle and bicycle in automobile during travelling on a road surface leads jerky, bound and rebound motion a bicycle or vehicle due to this problem by shock and vibration creates discomfort and unsafely to driver and passenger. The vibration coming from vehicle leads to pain, discomfort and dissipated heat and energy which impact on reduction in efficiency shock absorber on semi active suspension system. Comparison method of actual and design Shock absorber by reductions spring stiffness, use falling tube viscometer method for finding efficient fluid mixture for reducing shock and vibration amplitude of theoretical and experimental method. In this research more shock absorbent and energy efficient Shock Absorber Damper is developed for Splendor two wheeler to controlled the vibration of semi active suspension system of vehicle. The fluid greatly increases its viscosity and result in large damping force, less power consummation, fast and smooth response, and cost effective design and environmentally friendly. The damping force increase and decrease in leads to bounce and renounces.
... Additionally, other diverse types of springs have been developed depending on the design space for the same direction of force, such as compression coil spring, leaf spring, arc spring, and volute spring. By using these various types of springs, researchers have developed mechanical systems such as shock mitigation, energy storage, and mechanical recovery systems [1][2][3][4]. The field of application of spring-based mechanical systems has gradually expanded, for instance, the development of variable stiffness actuators that use the existing coil [5][6][7] and leaf springs [8][9][10]. ...
We present a hybrid spring system called CoiLeaf spring that offers superior space utilization and energy-storage performance by employing a combination of compression coil springs and leaf springs. The concept of this spring was verified in the design space of a compact variable gravity compensator (CVGC) developed by our group. Initially, we defined the space available for spring utilization in the CVGC as the Γ-space and allocated it to two design spaces for compression coil springs and leaf springs. Next, we derived the design constraints for the springs and optimized the compression coil spring on the basis of these constraints. Then, we selected a commercially available spring that was the closest to the optimized one. By contrast, the custom-fabricated leaf spring was optimally designed to maximize energy storage. Thereafter, we used Python scripting to construct the optimization process by linking finite element analysis software with mathematical computing software. Finally, we fabricated the proposed CoiLeaf spring. The energy storage capacity of the CoiLeaf spring system was experimentally measured as 11.38 J. Compared to the general systems utilized in the Γ-space, the maximum energy-storage capacity of the proposed CoiLeaf spring system was 5.47 times higher.© 2017 Elsevier Inc. All rights reserved.
... Composite compression spring has a lower weight and higher resistance to corrosion than conventional spring materials and is fuel-efficient for any car. Composite spring can be used at higher temperatures and higher loads, but it is difficult to design and produce [4]. ...
... The overall weight of the system became 178.75 kg [1753N]. Abdul Budan [4] checked feasibility of replacing the metal coil spring with the composite coil spring. Three different types of spring were made using glass fibre, carbon fibre and combination of a glass fi bre and a carbon fibre. ...
A suspension system is a mechanical device which is used to smooth out or damp shock impulse and dissipate kinetic energy. In vehicles problem happens while driving on bumping road condition so the rider feels uncomforted. Hence design of spring in shock absorber is very important. In this project, spring is designed and the 3D model is created using modelling software CATIA. Static analysis in done on the spring by varying materials as oil tempered spring steel and beryllium copper. The analysis is done by considering loads, bike weight, single person and two persons. In this analysis, maximum shear stress and total deformation is calculated using ANSYS software. And the comparison is done on two materials.
... Composite compression spring has a lower weight and higher resistance to corrosion than conventional spring materials and is fuel-efficient for any car. Composite spring can be used at higher temperatures and higher loads, but it is difficult to design and produce [4]. ...
For automotive manufacturers, the current scenario is to boost reliability and component performance along with increasing fuel efficiency and the cost of manufacturing. The inquiry is, therefore, being carried out into the use of substitute materials in the development component, increasing the strength-to-weight ratio. The best alternative materials until now were composite materials. This study includes traditional steel helical compression spring and then contrasted with composites used in the development of helical compression spring. The helical compression spring of TATA INDICA VISTA is used for analysis and the helical compression spring load is taken as 4544.3 N. The composite material is EGlass/Epoxy and Carbon/Epoxy. In modeling the helical compression spring, solid works 2013 are used and commercial Ansys 14.5 is used for static and modal analysis. The study shows that the natural frequency produced in the helical compression spring of the composite material is reduced in transverse mode, but increases in both compression and torsional mode.
... Advanced processes such as curved pultrusion have already been applied to several structures but lack deeper studies on in-service failure prediction. Budan and Manjunatha 16 experimentally investigated spirals produced using as reinforcement glass, carbon or glass/carbon combination. Tasdemir and Coker 17 experimentally studied the damage progression in curved CFRP composite laminates under static and fatigue loading. ...
Recent improvements in pultrusion and filament winding have allowed the manufacturing of spirals and rings composite profiles for applications such as fuselage reinforcements of small aircrafts, automotive bumper beams, automotive springs and structural reinforcement for pipes. However, the behavior of curved carbon fiber components is complex and hard to predict, and still demands deeper understanding. In this work, progressive damage and cohesive zone numerical models were used to simulate the behavior of unidirectional curved composite structures under flexural loading. Four-point bending tests were carried out on curved samples monitored by strain gages for model validation. The results have demonstrated a strong influence of delamination on samples with well-defined resin-rich areas. In contrast, curved structures with more homogeneous fiber distribution, i.e. those manufactured by curved pultrusion, showed increased flexural strength. Maximum stresses from numerical and experimental analyses were compared and the maximum difference found was below 3.5%.
... But, Metal springs are advantageous as they can be produced in different sizes and over a broad range of stiffness values. Fabrication of composite springs is an expensive and difficult as these materials are anisotropic in nature, thus the use of composites in manufacturing springs is not a common practice [6]. ...
Helical or coiled springs are elastic bodies used in suspension systems of automobiles to absorb shocks caused due to irregularities on the road surface and to provide a comfortable ride to passengers. Composite material springs may improve the performance of suspension springs by adding to weight reduction and improvements in corrosion resistance, durability and life of the suspension springs. In this study, three materials, namely Structural steel, S-Glass Epoxy composite and Epoxy-Carbon prepreg composite were chosen to study their applicability as automobile suspension springs. ANSYS analysis were carried out on these springs to measure the deformation at different loads and the stiffness of the springs. Even though composites exhibited lesser load carrying capacity compared to steel spring, their strength to weight ratio was noticeably higher. The weight of composite springs was found to be at least 75-80% lower than steel. The finite element technique, which was adopted, is validated with the theoretical models and the variation in deformation and stress results was well within the allowable limit of 5%.
... Using glass-filled polypropylene (PP) one can replace a more expensive metal version of door module [11]. In an experiment, the feasibility of replacing the metal coil spring with the composite coil spring has been demonstrated [12]. Metal replacement to engine cover components using mineral-reinforced nylon resin and Zytel nylon resin for two cast-aluminum parts resulted in less weight and cost, without affecting function or performance [13]. ...
... The results shown that an oscillatory behaviour of stresses along the length at inner side of the spring. Budan and Manjunatha [11] is investigated on the feasibility of composite coil spring for automotive applications. The three different composition of springs are fabricated such as glass fiber, carbon fiber and combination of glass fiber with carbon fiber. ...
... The results shown that an oscillatory behaviour of stresses along the length at inner side of the spring. Budan and Manjunatha [11] is investigated on the feasibility of composite coil spring for automotive applications. The three different composition of springs are fabricated such as glass fiber, carbon fiber and combination of glass fiber with carbon fiber. ...
An open coil and closed coil helical springs works usually under critical conditions due to the continuous variations of load acting on the top surface. The analysis of an open coil and closed coil helical springs of an automobile clutches are carried out in ‘ANSYS’ software and the experimental study has been conducted for different load conditions. The various parameters like total deformation, stress intensity, strain energy and equivalent von-misses stress are considered for study. An experiment has been carried out for total deformation of an open and closed coil helical springs at various loads like 500, 1000 and 1500 N. The experimental results shows a good agreement for the simulation results. The results shows that the performance of an open coil helical spring is good compared with closed coil helical spring.
... Most of the work has been done in the field of replacing the steel leaf spring with glass fiber composites [6][7][8][9][10][11][12][13]16]. Prediction of fatigue life is enhanced due to use of Life Data Analysis technique for composite and steel multi-leaf spring by Senthil Kumar and Vijayarangan [14]. ...
... The results shown that an oscillatory behaviour of stresses along the length at inner side of the spring. Budan and Manjunatha [11] is investigated on the feasibility of composite coil spring for automotive applications. The three different composition of springs are fabricated such as glass fiber, carbon fiber and combination of glass fiber with carbon fiber. ...
The aim of this work is to propose an analysis of the non-linear elastic behavior of a non-homogeneous spring, made of several successive layers, the goal is to reduce the weight of the spring while keeping the same stiffness of the steel spring. The resolution of the non-linear problem is done is done by high-order algorithm based on the steps of the asymptotic numerical method (ANM). By using a curvilinear finite element, defined along the mean line of the spring. The kinematics adopted in our theoretical formulation takes into account the hypotheses of Timoshenko. The comparative study is based on a parameter “e” which represents the percentage of the outer layer in relation to the inner layer, the results are compared to the homogeneous case. Numerical tests using a simple example showed the possibility of reducing the weight of the homogeneous steel spring, by replacing it with a composite two-layer steel-carbon spring, where the carbon content does not exceed 10%.KeywordsComposite springTimoshenko cinematicCurvilinear finite element methodAsymptotic Numerical Method (ANM)
Compared with steel helical spring widely used in automobiles, composite helical springs with nonlinear stiffness (NS-CHS) not only have obvious advantages such as significant lightweight effect and corrosion resistance, but also provide the optimal stiffness according to the requirements of automobile suspension under different working conditions, which is of great significance for the dynamic performance and comfort of automobiles. Therefore, its design method has gained considerable attention in the application field of composite structures. In this work, a theoretical model used for stiffness matching design and structure optimization of NS-CHS was established. Then, the key influencing factors of stiffness, the FEM analysis method and the manufacturing process of NS-CHS are studied, and the model is verified by related test results. The proposed theoretical model not only considers the main features of the composite structure and the anisotropy of composite material, but also provides a new numerical method for the design and structure optimization of composite elastic structures with helical shape.
This paper is about the theoretical and experimental characterizations of the torsional vibration behavior of circular and rectangular cross-sectional arc springs. Firstly, the dynamic behaviors of arc springs with different cross-sectional wire profiles designed for a dual mass flywheel are modeled by mathematical formulations. After that, experimental tests are performed to verify these models and it is observed that the stiffness characterizations are in good agreement with experimental results. Lastly, the masses of two different arc springs are compared by regarding the same vibration stiffness criteria and it is demonstrated that the rectangular wire provides an arc spring with a 9.44 vol.-% lighter structure. Thus, the outcomes of this paper can be good references for the manufacturer about the numerical and experimental characterization of dual mass flywheel springs, especially for rectangular wire arc springs.
Composite helical spring has gained considerable attention due to its high strength to weight ratio and corrosion resistant. It can also be utilized for different applications such as automobile suspension and railway bogie. Therefore, its design method and performance investigation are the research hotspots in the application field of composite structures. This work attempts to review most of the studies carried out on the design method of composite helical springs, including material selection, structure design, performance matching design and optimization design. Moreover, important research results on the performance investigation and manufacturing process of composite helical springs are also highlighted. Finally, the emerging trends in the research of composite helical springs are discussed.
Chapter 5 explores the torsion and bending of driveshafts made of composite. The driveshaft is modeled as an anisotropic rod with a solid or thin‐walled tubular cross‐section. The dominant load on the driveshaft is torque that causes high shear stress in the material. The alternating torque also causes twist vibration modes. The secondary loads are bending and tension. The resulting stresses from secondary loads are usually moderate but can provoke Greenhill's torque instability and bending vibration modes. From the lightweight viewpoint, the advantageous design of driveshafts is the thin‐walled tubular structure. The corresponding model of a thin‐walled anisotropic driveshaft is based on the kinematic hypotheses and equations of thin anisotropic shells. The kinematic hypotheses assume that the normal cross‐section profile of a thin‐walled shaft is not distorted but instead is only rotated and displaced in space. Using kinematic hypotheses, the strains and curvatures of the middle surface of the shaft are displayed. Strain equations are obtained by varying the potential energy functional of the classical theory of anisotropic shells. Finally, the problem of determining the critical load for a thin‐walled driveshaft in axial compression is investigated. The proposed model is appropriate for analysis of driveshafts made of multilayered composite materials. As mentioned, elongated driveshafts are subjected to Greenhill's twist buckling. If twist instability occurs, the straight axis of twisted rod transforms to the helical spiral curve. This motivates the pursuit for the optimal cross‐sectional shape of a driveshaft. Remarkably, the optimal shape of cross‐section of a shaft for the maximal critical torque is a hollow triangle. On the contrary, circular hollow cross‐section leads to the minimum shear stress under given torque. Accordingly, the short driveshafts preferably must have a circular hollow cross‐section, while lengthy driveshafts should have a triangular hollow form of profile.
Applkicability of Composite Helical Springs to Automobile suspension
Safety and driving comfort for car’s driver are both dependent on vehicle’s suspension system. Safety refers to the vehicle’s handling and braking capabilities whereas comfort of the occupants of a car correlates to tiredness and ability to travel long distance with minimal annoyance. The need for dampers arises due to the roll and pitches associated with vehicle maneuvering, and from the roughness of roads. Rapidly increasing power available from the internal combustion engine made higher speeds routine; plus the technical aptitude of the vehicle and component designs, coupled with a general commercial mood favoring development provided an environment that led to invention and development of shock absorbers. FSAE is an international design competition that aims at building a prototype of a Formula style race car for the non-professional weekend autocross racer. Each team designs, builds and tests a prototype based on a series of rules whose purpose is both to ensure onsite event operations and promote clever problem solving. One of the major cause of failure of the suspension system is the failure of shock absorber spring due to fatigue. Taking this into account, our aim is to select an appropriate material which can be used for the shock absorber spring by analyzing certain commonly used materials. This report follows a detailed design methodology and describes the criteria and factors for selection of the materials. It encompasses several iterations, and establishes reasoning for the most suitable material. The designed shock absorber is a mono-tube hydraulic type. Hence based on the shock absorber used in the race car our project aims at optimizing the material of the shock absorbers. Designing of the model was done on solidworks and analysis was performed on ansys. This study explains the groundwork laid for the selection of the best shock absorber material which can be used in the years to come.
To successfully reduce a vehicle's weight by replacing steel with composite materials, it is essential to optimize the material parameters and design variables of the structure. In this study, we investigated numerical and experimental methods for determining the ply angles and wire diameters of carbon fiber/epoxy composite coil springs to attain a spring rate equal to that of an equivalent steel component. First, the shear modulus ratio for two materials was calculated as a function of the ply angles and compared with the experimental results. Then, by using the equation of the spring rate with respect to the shear modulus and design variables, normalized spring rates were obtained for specific ply angles and wire diameters. Finally, a finite element model for an optimal composite coil spring was constructed and analyzed to obtain the static spring rate, which was then compared with the experimental results.
This paper shows the feasibility of using carbon-fiber-reinforced polymer (CFRP) composite materials for manufacturing automotive coil springs. For achieving weight reduction by replacing steel with composite materials, it is essential to optimize the material parameters and design variables of the coil spring. First, the shear modulus of a CFRP beam model, which has ply angles for maximum torsional stiffness, was calculated and compared with the test results. The diameter of the composite spring was predicted to be 17.5 mm for ensuring a spring rate equal to that when using steel material. Finally, a finite element model of the composite coil spring with ply angles and 17.5 mm wire diameter was constructed and analyzed for obtaining the static spring rate, which was then compared with experimental results.
Design and manufacture of a functional composite spring for a solar powered light vehicle is described. The objective is not to compare composite spring systems using different types of springs such as rubber disks, air shocks, etc., but to provide an understanding of the manufacture, use, and capabilities of composite leaf springs produced by using unidirectional E-glass roving impregnated by an epoxy resin for light vehicle applications where the vehicle weight is of primery concern. The current design application involves a solar powered car.
Details are given of an investigation into the replacement of a conventional steel coil spring in the suspension system of a production car by a coil spring in fibre reinforced plastics. The development of the design and manufacturing techniques is described and the results of static and fatigue testing of prototype springs in carbon fibre reinforced plastics are discussed.
Fiber reinforced plastics are undergoing extensive studies as potential structural materials for automotive applications. This paper describes the design, fabrication, weight analysis and testing of a composite integrated rear suspension in a Ford Escort vehicle. This suspension utilizes a transverse FRP leaf spring to integrate the functions of the production Escort stamped steel lower arms and coil springs. The spring was designed using previously developed composite design procedures. The results show concept feasibility, a vehicle weight saving of 7 lb, good ride, noise, vibration and harshness (NVH) characteristics. A reduction in roll stiffness points out the need for development in the design of the center clamp attachment to the body structure. This study demonstrates the viability and potential of fiber reinforced composites in automotive suspension systems.
Carbon-carbon composites used in friction systems are becoming increasingly popular in aircrafts owing to their combination of low weight and high performance. Their current acceptance as brake materials is somewhat restrained due to two factors: cost and performance variations. Many manufacturers are taking steps toward improving their cost efficiency by utilizing lower cost precursor fibers and processing methodologies. At the same time, modifications to material properties are made to address performance issues of oxidation, wear, and variation of effectiveness. This paper describes the present status of the production technologies employed and details some of the remaining issues relative to braking performance.
Mechanical design can be classified into stiffness design and strength design. In the stiffness design, the stiffness or deformation of members is concerned, and the enhancement of dynamic characteristics such as natural frequency or damping capacity of members or systems is also important. While, in the strength design, the primary concern is the enhancement of load carrying ability of members or systems.Fiber reinforced composite materials offer a combination of strength and modulus that are either comparable to or better than many traditional metallic materials. Because of their low specific gravities, the strength-weight ratios, and modulus-weight ratios of these composite materials are much superior to those metallic materials. Composite materials can be tailored to meet the specific requirements of each particular design. Available design parameters are the choice of materials (fiber, matrix), the volume fraction of fiber and matrix, fabrication method, number of layers in a given direction, thickness of individual layers, type of layer (unidirectional or fabric), and the layer stacking sequence.The greatest disadvantages of composite materials are the costs of the materials and the lack of well-defined design rules, therefore, composite materials should be applied in the right place with appropriate design rules. Up to now, the fiber reinforced composite structures are mainly employed in the strength design such as aircraft, spacecraft and vehicles.In this paper, the novel application examples of composite structures to components for the robots, machine tools and automobiles are addressed considering the stiffness design issues of composite structures.
The fuel efficiency and emission gas regulation of passenger cars are two important issues nowadays. The best way to increase fuel efficiency without sacrificing safety is to employ fibre-reinforced composite materials in the body of cars because fibre-reinforced composite materials have higher specific strengths than those of steel.In this study, the side-door impact beam for passenger cars was developed using glass-fibre-reinforced composite materials as metals usually have a lower capacity of impact absorption energy at low temperature compared with that of glass-fibre-reinforced composite materials. Static tests were carried out to determine the optimum fibre stacking sequences and cross-sectional thickness for the composite impact beams taking consideration of the weight saving ratio compared to the high strength steel.Dynamic tests were carried out at several different temperatures using the pneumatic impact tester, which was developed to investigate the dynamic characteristics of impact beams at a speed of 30 mph. Also, finite-element analyses were performed using ABAQUS, a commercial software to compare the simulated characteristics of the impact beams with the experimental results.From the comparison, it was found that the results from the finite-element analyses showed good agreement with the experimental results, although several assumptions were made in the finite-element analyses.