scholarly journals Experimental and numerical analysis of the static strength and fatigue life reliability of parabolic leaf springs in heavy commercial trucks

2020 ◽  
Vol 12 (7) ◽  
pp. 168781402094195
Author(s):  
Ufuk Taner Ceyhanli ◽  
Mehmet Bozca
Keyword(s):  
Finite Element ◽  
Fatigue Life ◽  
Numerical Analysis ◽  
Reliability Analysis ◽  
Static Loading ◽  
Static Strength ◽  
Design Stage ◽  
Leaf Spring ◽  
Leaf Springs ◽  
Parabolic Leaf Spring

The objective of this study is to perform experimental and numerical analysis of the static strength and fatigue life reliability of parabolic leaf springs in heavy commercial trucks. To achieve this objective, stress and displacements under static loading were analytically calculated. A computer-aided design model of a parabolic leaf spring was created. The stress and displacements were calculated by the finite element method. The spring was modelled and analysed using CATIA Part Design and ANSYS Workbench. The stress and displacement distributions on a three-layer parabolic leaf spring were obtained. The high-strength 51CrV4 spring steel was used as sample parabolic leaf springs material, and heat treatments and shoot peening were applied to increase the material strength. Sample parabolic leaf springs were tested to obtain stress and displacement under static loading conditions. By comparing three methods, namely, the static analytical method, static finite elements method and static experimental method, it is observed that results of three methods are close to each other and all three methods are reliable for the design stage of the leaf spring. Similarly, sample parabolic leaf springs were tested to evaluate the fatigue life under working conditions. The reliability analysis of the obtained fatigue life test value was carried out. It was shown that both analytical model and finite element analysis are reliable methods for the evaluation of static strength and fatigue life behaviour in parabolic leaf springs. In addition, it is determined by a reliability analysis based on rig test results of nine springs that the spring achieves its life cycle of 100,000 cycles with a 99% probability rate without breaking. Furthermore, the calculated fatigue life is 2.98% greater than experimentally obtained fatigue life mean and the leaf spring can be used safely and reliably during the service period in heavy trucks.

A simple analytical bending stress model of parabolic leaf spring

2017 ◽  
Vol 232 (10) ◽  
pp. 1838-1850 ◽  
Author(s):  
Akram Atig ◽  
Rabii Ben Sghaier ◽  
Raoudha Seddik ◽  
Raouf Fathallah
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Fatigue Life ◽  
Stress Distribution ◽  
Leaf Spring ◽  
Bending Stress ◽  
Uniform Load ◽  
Element Analysis ◽  
The Finite Element Analysis ◽  
Parabolic Leaf Spring

The evaluation of stress distribution, produced by vertical loading along a parabolic leaf spring, presents an essential aspect during the design stage. Commonly, designers utilize the finite element analysis to simulate the stress behaviour of a parabolic leaf spring. Nevertheless, the use of such method is a time-consuming process during the deterministic and the reliability-based fatigue design optimisation. In this study, we propose three analytical models describing the bending stress distribution of a simply supported single asymmetric parabolic leaf spring: (i) an initially curved single asymmetric parabolic leaf spring, subjected to a concentrated load; (ii) a straight single asymmetric parabolic leaf spring, subjected to a uniform load and (iii) an initially curved single asymmetric parabolic leaf spring, subjected to a uniform load. Bending stress distribution results of classical, finite element and proposed models are compared for several case studies. It is observed that the third model is the most precise model compared to the finite element analysis of single asymmetric parabolic leaf spring. Therefore, the suggested model can be used to generate fatigue life diagram that predicts the required mean and alternating load values for a desired fatigue life with an acceptable accuracy and a reduced computational time.

Finite Element Method-based geomechanical risk assessment of underground laboratory located in the deep copper mine

2021 ◽  
Author(s):  
Krzysztof Fulawka ◽  
Witold Pytel ◽  
Piotr Mertuszka ◽  
Marcin Szumny
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Numerical Analysis ◽  
New Technologies ◽  
Radiation Detection ◽  
Underground Laboratory ◽  
Design Stage ◽  
Copper Mine ◽  
Geophysical Surveys ◽  
Element Method

<p>Underground laboratories provide a unique environment for various industries and are a suitable place for developing new technologies for mining, geophysical surveys, radiation detection, as well as many other studies and measurements. Unfortunately, any operation in underground excavations is associated with exposure to many hazards not necessarily encountered in surface laboratories. One of the most dangerous events observed in underground conditions is the dynamic manifestation of rock mass pressure in form of rockburst, roof falls and mining tremors. Therefore, proper evaluation of geomechanical risk is a key element ensuring the safety of work in underground conditions. Finite Element Method-based numerical analysis is one of the tools which allow conducting a detailed geomechanical hazard assessment already at the object design stage. The results of such calculations may be the basis for the implementation of preventive measures before running up the underground facility.</p><p>Within this paper, the three-dimensional FEM-based numerical analysis of large-scale underground laboratory located in deep Polish copper mine was presented. The calculations were made with GTS NX software, which allowed determining the changes in the safety factor in surrounding of the analyzed area. Finally, the possibility of underground laboratory establishment, with respect to predicted stress and strain conditions, were determined.</p>

Effect of End Rubber Gasket on the Performance of Parabolic Leaf Spring

2020 ◽  
Author(s):  
Junhong Zhang ◽  
Feiqi Long ◽  
Hongjie Jia ◽  
Jiewei Lin
Keyword(s):  
Ride Comfort ◽  
Orthogonal Experiment ◽  
Element Model ◽  
Considerable Effect ◽  
Leaf Spring ◽  
Static Stiffness ◽  
Rubber Gasket ◽  
Maximum Deformation ◽  
Leaf Springs ◽  
Parabolic Leaf Spring

Abstract Leaf springs play an important role in the handling stability and ride comfort of vehicle. End rubber gaskets are widely used to reduce the friction between leaves, but they also have considerable effect on the stiffness of the suspension assembly. The ride comfort may deteriorate with the stiffness of leaf spring changes. In this paper the influence of the end rubber gasket on the static stiffness performance of a parabolic leaf spring is studied. A finite element model of the leaf spring is developed and verified against the static stiffness test. Effects of the end rubber gasket parameters on the static stiffness of the leaf spring are analyzed based on an orthogonal experiment. The sensitivities of the five parameters are identified including the width, the length, the end thickness, the tail thickness and the distance to the end of the middle leaf. It is found that the contributions can be ranked in descending order as the tail thickness, the end thickness, the distance from end rubber gasket to the end of Leaf 2, and the width and length. The first two factors are considered of significant effects on the leaf spring stiffness. According to single-factor analysis, it is found that under the same load, as the tail thickness and the end thickness increase, the maximum deformation of the rubber gasket decreases, the stiffness of the rubber gasket increases, and the stiffness of the leaf spring increases, which provides a reference for the forward design of the end rubber gasket and the stiffness matching of leaf springs.

scholarly journals Fatigue Life Assessment of 65Si7 Leaf Springs: A Comparative Study

2014 ◽  
Vol 2014 ◽  
pp. 1-11 ◽  
Author(s):  
Vinkel Kumar Arora ◽  
Gian Bhushan ◽  
M. L. Aggarwal
Keyword(s):  
Fatigue Life ◽  
Testing Machine ◽  
Life Assessment ◽  
Leaf Spring ◽  
Analytical Technique ◽  
Fatigue Life Assessment ◽  
Leaf Springs ◽  
Light Commercial Vehicle ◽  
Load Rate ◽  
Solid Works

The experimental fatigue life prediction of leaf springs is a time consuming process. The engineers working in the field of leaf springs always face a challenge to formulate alternate methods of fatigue life assessment. The work presented in this paper provides alternate methods for fatigue life assessment of leaf springs. A 65Si7 light commercial vehicle leaf spring is chosen for this study. The experimental fatigue life and load rate are determined on a full scale leaf spring testing machine. Four alternate methods of fatigue life assessment have been depicted. Firstly by SAE spring design manual approach the fatigue test stroke is established and by the intersection of maximum and initial stress the fatigue life is predicted. The second method constitutes a graphical method based on modified Goodman’s criteria. In the third method codes are written in FORTRAN for fatigue life assessment based on analytical technique. The fourth method consists of computer aided engineering tools. The CAD model of the leaf spring has been prepared in solid works and analyzed using ANSYS. Using CAE tools, ideal type of contact and meshing elements have been proposed. The method which provides fatigue life closer to experimental value and consumes less time is suggested.

Crack Non-Circularity and Finite Erosion Effects on the 3D SIFs of a Bauschinger Modified Pressurized Thick-Walled Cylinder

2015 ◽  
Author(s):  
Qin Ma ◽  
Cesar Levy ◽  
Mordechai Perl
Keyword(s):  
Residual Stress ◽  
Finite Element ◽  
Fatigue Life ◽  
Numerical Analysis ◽  
Material Properties ◽  
Thermal Loading ◽  
Circular Crack ◽  
Finite Element Package ◽  
Pressurized Cylinder ◽  
Walled Cylinder

Our previous studies have demonstrated that the 3D SIFs of a pressurized cylinder can be greatly affected by many factors. While an autofrettage process may introduce favorable residual stresses at the bore of the cylinder, other factors such as erosions and cracks, once introduced, may greatly reduce the effectiveness of the autofrettage results. In this study, we focus on how the non-circularity of cracks affects the 3D SIFs for a cylinder that contains finite erosions while keeping other conditions and material properties unchanged. Numerical analysis was performed using ANSYS, a standard commercially available finite element package. The residual stress due to any autofrettage process was simulated using the equivalent thermal loading. A closer look was given to problems with different crack configurations and how non-circularity of cracks affects the overall fatigue life of the cylinder when combined with other factors in comparison with circular crack only configurations.

Comparing Fatigue Life Reliability of a Composite Leaf Spring With a Steel Leaf Spring

Volume 1 ◽  
2004 ◽  
Author(s):  
Nima Shamsaei ◽  
Davood Rezaei
Keyword(s):  
Fatigue Life ◽  
Fatigue Behavior ◽  
Minimum Weight ◽  
Time Spectrum ◽  
Leaf Spring ◽  
Critical Element ◽  
Steel Spring ◽  
Leaf Springs ◽  
Long Time ◽  
External Forces

In the present study, the fatigue behavior of an optimized composite leaf spring and a four leaf steel spring have been analyzed and compared. In a paper, issued by co-author, a four leaf steel spring was replaced by a composite leaf spring. The geometry of composite spring has been optimized to obtain the minimum weight under stress and displacement constraints due to the given static external forces. In this study, both above-mentioned leaf springs have been fatigue analyzed. The vehicle movement has been simulated on four different standard roads in ADAMS software and the spring supports reactions have been derived. Stress time spectrum micro-blocks in critical element of leaf springs have been obtained using ANSYS software and considering ADAMS results as loading. The stress time spectrum macro-blocks for long time from the stress time spectrum in micro-blocks have been created according to statistical and random vibration principles. After finding stress probability density functions for composite leaf spring and equivalent steel leaf spring, fatigue reliabilities have been extracted for both of them. Results showed that the fatigue life reliability in composite leaf spring is much better than steel spring.

scholarly journals Static Analysis and Fatigue Life Prediction of Composite Leaf Springs of Automotive Suspension System

2019 ◽  
Vol 8 (4) ◽  
pp. 5147-5150
Keyword(s):  
Fatigue Life ◽  
Fuel Efficiency ◽  
Life Cycles ◽  
Life Assessment ◽  
Leaf Spring ◽  
Commercial Vehicles ◽  
Safety Standards ◽  
The Road ◽  
Leaf Springs ◽  
Automotive Suspension

Development of vehicles with the highest safety standards and lowest carbon emissions has been one of the primary goals of the automobile manufacturers. One of the methods of achieving higher fuel efficiency is by reducing vehicle weight by minimizing the unsprung weight without compromising strength and driver comfort. The study presents the behavior of the double-bolted-end joint semi-elliptical leaf spring that is generally used in the rear suspension of lightweight cars and commercial vehicles. 65si7 grade steel is conventionally used in the above leaf springs. The study evaluates the stress distribution, deflection and fatigue life assessment of leaf springs made up of glass epoxy (62% glass fiber), carbon epoxy (40% carbon fiber), and aluminum graphite (5% graphite). The results are compared with 65si7 steel leaf spring and analysed. The analysis performed showed a weight reduction of 76.4 %, 81.1%, 65.8% respectively. The first natural frequency was approximately 1.2 times greater than the road frequency. The simulated results for fatigue life cycles of leaf spring (10e5 cycles) was observed, whereas, for the conventional steel leaf spring (2e5 cycles) was observed. The results suggest the material aluminum graphite (5% graphite) will be the best replacement, considering the overall weight to strength ratio and cost

Development of Software System of Crawler Crane Platform Fatigue Life Reliability Analysis

2011 ◽  
Vol 121-126 ◽  
pp. 3890-3894
Author(s):  
Jia Li ◽  
Feng Wu Lu ◽  
Fei Zhao ◽  
Xiu Qian Zhang
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Fatigue Life ◽  
Reliability Analysis ◽  
Parametric Design ◽  
Spare Parts ◽  
Software System ◽  
Analysis Model ◽  
Element Analysis ◽  
Crawler Crane

Platform is one of the most important load-carrying parts of crawler cranes, one software system of crawler crane platform fatigue life reliability analysis is developed in the paper. It is based on the finite element analysis model by applying parametric design language APDL Using ANSYS Transient analysis, the rain-flow counting method has been adopted to deal with stress spectrum by the mean of combining related spare parts material P-S-N curves and adopting Miner linearity fatigue accumulation damage theory. It is developed under Visual Basic6.0 and Access 2007 database, it include five function modules: parametric finite element modeling, finite element analysis, optimization and fatigue life reliability analysis, it has important value to improve the design of crawler cranes.

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