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1 – 10 of over 5000Georgios Savaidis, Michail Malikoutsakis and Alexander Savaidis
The purpose of this paper is to develop a FE based modeling procedure for describing the mechanical behavior of high‐performance leaf springs made of high‐strength steels under…
Abstract
Purpose
The purpose of this paper is to develop a FE based modeling procedure for describing the mechanical behavior of high‐performance leaf springs made of high‐strength steels under damaging driving manoeuvres.
Design/methodology/approach
The type and number of finite elements over the thickness of leaves, as well as the definition of contact, friction and clamping conditions, have been investigated to describe the mechanical behavior in an accurate and time‐effective manner. The proposed modeling procedure is applied on a multi‐leaf spring providing complex geometry and kinematics during operation. The calculation accuracy is verified based on experimental stress results.
Findings
A FE based modeling procedure is developed to describe the kinematics and mechanical behavior of high‐performance leaf springs subjected till up to extreme driving loads. Comparison of numerically determined stress distributions with corresponding experimental results for a serial front axle multi‐leaf spring providing complex geometry and subjected to vertical and braking loads confirms high calculation accuracy.
Research limitations/implications
The proposed FE based model is restricted to linear elastic material behavior, which is, however, reasonable for the high‐strength steels used for leaf spring applications.
Practical implications
The proposed FE procedure can be applied for the design and optimization of automotive leaf springs, especially for trucks.
Originality/value
The proposed procedure is simple and can be applied in a very early design stage. It is able to describe accurately the leaf behavior, especially the stiffness and stress response under the most significant driving events. It goes far beyond today's practice for leaf spring design, which is based on analytical methods not covering complex axle and steering kinematics, large deformations and non‐linearities.
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Karthikeyan Marappan, Jenarthanan M.P. and Sree Krishna B.
The main purpose of this proposed parabolic leaf spring (PLS) is to reduce the weight of the steel leaf spring by developing a new design, to increase the load-carrying capacity…
Abstract
Purpose
The main purpose of this proposed parabolic leaf spring (PLS) is to reduce the weight of the steel leaf spring by developing a new design, to increase the load-carrying capacity, to increase the ride comfort for the passengers and also to achieve a substantial weight reduction in the suspension system by replacing the semi-elliptic leaf spring.
Design/methodology/approach
The semi-elliptic steel leaf spring and the PLS are compared based on the load-carrying capacity and weight. The design constraints are stresses and deflection. The dimensions of the HM trekker Jeep semi-elliptic leaf springs are taken. A three-dimensional model is created, and the static structural analysis is performed. The semi-elliptic leaf spring is tested on a universal testing machine, and the experimental result is compared with the analytical result for the validation. After validation, the stress analysis of the PLS is carried out and compared with the stress analysis of the semi-elliptic leaf spring.
Findings
The results show that the developed PLS performs better than the semi-elliptic leaf spring in terms of load-carrying capacity and weight reduction.
Originality/value
Comparison between the semi-elliptic leaf spring and the PLS (static structural analysis and dynamic analysis) has not been carried out before.
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Lennie Abdullah, Salvinder Singh Karam Singh, Abdul Hadi Azman, Shahrum Abdullah, Ahmad Kamal Ariffin Mohd Ihsan and Yat Sheng Kong
This study aims to determine the reliability assessment based on the predicted fatigue life of leaf spring under random strain loading.
Abstract
Purpose
This study aims to determine the reliability assessment based on the predicted fatigue life of leaf spring under random strain loading.
Design/methodology/approach
Random loading data were extracted from three various road conditions at 200 Hz using a strain gauge for a duration of 100 s. The fatigue life was predicted using strain-life approaches of Coffin–Manson, Morrow and Smith–Watson–Topper (SWT) models.
Findings
The leaf spring had the highest fatigue life of 1,544 cycle/block under highway data compared uphill (1,299 cycle/block) and downhill (1,008 cycle/block) data. Besides that, the statistical properties of kurtosis showed that uphill data were the highest at 3.81 resulted in the presence of high amplitude in the strain loading data. For fatigue life-based reliability assessment, the SWT model provided a narrower shape compared to the Coffin–Manson and Morrow models using the Gumbel distribution. The SWT model had the lowest mean cycle to failure of 1,250 cycle/block followed by Morrow model (1,317 cycle/block) and the Coffin–Manson model (1,429 cycle/block). The SWT model considers the mean stress effects by interpreting the strain energy density that will influence the reliability assessment.
Research limitations/implications
The reliability assessment based on fatigue life prediction is conducted using the Gumbel distribution to investigate the behaviour of fatigue random loading, where most previous studies had concentrated on a Weibull distribution on random data.
Originality/value
Thus, this study proposes that the Gumbel distribution is suitable for analysing the reliability of random loading data in assessing with the fatigue life prediction of a heavy vehicle leaf spring.
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It is shown that a reduction of the bending moments in a helicopter rotor blade may be achieved by replacing an elastic beam‐type flapping hinge by a stack of leaf‐springs having…
Abstract
It is shown that a reduction of the bending moments in a helicopter rotor blade may be achieved by replacing an elastic beam‐type flapping hinge by a stack of leaf‐springs having the same overall bending stiffness but no shear stiffness. This reduction becomes more pronounced when the tensile load on the flapping hinge is increased.
Sachin Negi, Ujjwal Sagar, Vijay Kumar Nautiyal and Neeraj Sharma
This paper aims to design and analyze a controlled magnetorheological damper-based ankle-foot prosthesis prototype.
Abstract
Purpose
This paper aims to design and analyze a controlled magnetorheological damper-based ankle-foot prosthesis prototype.
Design/methodology/approach
The ankle-foot prostheses prototype is proposed using the lightweight three dimensional (3 D)-printed parts, MR damper and digital servomotor. Initially, the computer-aided design (CAD) model of the prosthetic foot, leaf spring, retention spring and the various connecting parts required to connect the pylon and damper actuator assemblies are designed using CAD software. Later, the fused deposition modeling 3 D printer-based technique prints a prosthetic foot and other connecting parts using Acrylonitrile Butadiene Styrene filament. The prototype consists of two control parts: the first part controls the MR actuator that absorbs the impacts during walking. The second part is the control of the electric actuator intended to generate the dorsiflexion and plantar flexion movements. Finally, the prototype is tested on a transtibial amputee under the supervision of a prosthetist.
Findings
The ANalysis SYStems software-based analysis has shown that the prosthetic foot has a factor of safety values between 4.7 and 8.7 for heel strike, mid-swing and toe-off; hence, it is safe from mechanical failure. The designed MR damper-based ankle-foot prosthesis prototype is tested on an amputee for a level-ground walk; he felt comfortable compared to his passive prosthesis.
Originality/value
The design of an MR damper-based prosthesis prototype offers a better dynamic range for locomotion than passive prostheses. It reduces the injuries and provides relief to the transtibial amputees.
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Robert W. Messler, Suat Genc and Gary A. Gabriele
Suggests that, without question, while every step in a systematic approach to the design of parts for assembly using integral snap‐fit features is important, none is more…
Abstract
Suggests that, without question, while every step in a systematic approach to the design of parts for assembly using integral snap‐fit features is important, none is more important than selecting locking features. After all, it is these features that hold the assembly together. While quite different in appearance and details of their operation, all integral locking features comprise a latch and a catch component to create a locking pair. Proper, no less optimum, function requires that such locking pairs be selected using a systematic approach. Presents that approach as a six‐step methodology, but first, defines and describes latch and catch components, bringing order to their apparent boundless variety. Demonstrates the utility of the methodology with a real‐life case study.
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M. Grujicic, B. Pandurangan, I. Haque, B.A. Cheeseman, W.N. Roy and R.R. Skaggs
The kinematic response (including plastic deformation, failure initiation and fracture) of a soft‐skinned vehicle (represented by a F800 series single‐unit truck) to the…
Abstract
The kinematic response (including plastic deformation, failure initiation and fracture) of a soft‐skinned vehicle (represented by a F800 series single‐unit truck) to the detonation of a landmine shallow‐buried in (either dry or saturated sand) underneath the vehicle’s front right wheel is analyzed computationally. The computational analysis included the interactions of the gaseous detonation products and the sand ejecta with the vehicle and the transient non‐linear dynamics response of the vehicle. A frequency analysis of the pressure versus time signals and visual observation clearly show the differences in the blast loads resulting from the landmine detonation in dry and saturated sand as well as the associated kinematic response of the vehicle. It is noted that the dominant vehicle structural response to the blast is similar to the first torsional structural mode shape obtained through an eigenvalue analysis of the system. Tailoring the vehicle modal response may result in more desirable modes of failure.
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The paper presents results of a pilot project on technological innovation of main flexible components for automotive suspension systems, that are coil springs and stabilizer bars…
Abstract
The paper presents results of a pilot project on technological innovation of main flexible components for automotive suspension systems, that are coil springs and stabilizer bars. Current technology has been described and related problems have been outlined. In order to fulfil features such as compactness, lightness and environmentally conscious design, solutions based on new forms, materials and manufacturing processes have been proposed. Improvements in weights, dimensions, noiselessness, corrosion and fatigue strength, environmental effects, have been all assessed, keeping a quite low project cost (around $3 million).
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This paper gives a review of the finite element techniques (FE) applied in the analysis and design of machine elements; bolts and screws, belts and chains, springs and dampers…
Abstract
This paper gives a review of the finite element techniques (FE) applied in the analysis and design of machine elements; bolts and screws, belts and chains, springs and dampers, brakes, gears, bearings, gaskets and seals are handled. The range of applications of finite elements on these subjects is extremely wide and cannot be presented in a single paper; therefore the aim of this paper is to give FE researchers/users only an encyclopaedic view of the different possibilities that exist today in the various fields mentioned above. An Appendix included at the end of the paper presents a bibliography on finite element applications in the analysis/design of machine elements for 1977‐1997.
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THE Greater London Council's conference hall, which can hold several hundred people, was packed to capacity in the evening of March 3. The suspicion that it was a mass gathering…
Abstract
THE Greater London Council's conference hall, which can hold several hundred people, was packed to capacity in the evening of March 3. The suspicion that it was a mass gathering to hear a party leader expound national issues was only dispelled by a realization that it was a trifle easy.