Strength Safety Coefficient and Fatigue Life Analysis of Coupling Diaphragm Based on FE-Simulation

2014 ◽  
Vol 541-542 ◽  
pp. 569-573 ◽  
Author(s):  
Zhong Ke Tian ◽  
Chao Yin ◽  
Fa He Yang

Based on average loading assumption, a non-linear contact finite element model of coupling triple-diaphragm assembly configuration is established. In accordance with the result of diaphragm equivalent stress, the yield strength criterion and high cycle-stress fatigue life norm are adopted to calculate strength safety coefficient and fatigue life of coupling diaphragm. The durability of coupling diaphragm is proved enough numerically.

Author(s):  
Zhenguo Lu ◽  
Lirong Wan ◽  
Qingliang Zeng ◽  
Xin Zhang ◽  
Kuidong Gao

Conical picks are the key cutting components used on roadheaders, and they are replaced frequently because of the bad working conditions. Picks did not meet the fatigue life when they were damaged by abrasion, so the pick fatigue life and strength are excessive. In the paper, in order to reduce the abrasion and save the materials, structure optimization was carried out. For static analysis and fatigue life prediction, the simulation program was proposed based on mathematical models to obtain the cutting resistance. Furthermore, the finite element models for static analysis and fatigue life analysis were proposed. The results indicated that fatigue life damage and strength failure of the cutting pick would never happen. Subsequently, the initial optimization model and the finite element model of picks were developed. According to the optimized results, a new type of pick was developed based on the working and installing conditions of the traditional pick. Finally, the previous analysis methods used for traditional methods were carried out again for the new type picks. The results show that new type of pick can satisfy the strength and fatigue life requirements.


Author(s):  
Recep M. Gorguluarslan ◽  
Seung-Kyum Choi

This research examines classification approaches for estimating the reliability of structural systems. To validate the accuracy and efficiency of the classification methods, a practical engineering problem; namely, a spider assembly of a washing machine, has been considered. For the spider assembly, fatigue life test, finite element analysis, physical experimentation, and a classification processes are conducted in order to establish the analytical certification of its current design. Specifically, the finite element analysis and fatigue life analysis are performed and their results are validated compared to physical experimental results. The classification process is developed to estimate the probability of failure of the spider assembly in terms of stress and fatigue life. The relationship between the random quantities and structural responses of the spider assembly is established using probabilistic neural network and the support vector machine classifiers. The performance margin of the spider assembly is fully identified based on the estimated failure probability and structural analysis results from the fatigue life analysis and classifications.


Author(s):  
Massimiliano Gobbi ◽  
Giorgio Previati ◽  
Giampiero Mastinu

An off-road motorcycle frame has been analyzed and modified to optimize its fatigue life. The fatigue life of the frame is very important to define the service life of the motorcycle. The strain levels on key parts of the frame were collected during experimental tests. It has been possible to locate the areas where the maximum stress level is reached. A finite element (FE) model of the frame has been developed and used for estimating its fatigue life. Static test bench results have been used to validate the FE model. The accuracy of the finite element model is good, the errors are always below 5% with respect to measured data. The mission profile of the motorcycle is dominated by off-road use, with stress levels close to yield point, so a strain-life approach has been applied for estimating the fatigue life of the frame. Particular attention has been paid to the analysis of the welded connections. A shell and a 3D FE model have been combined to simulate the stress histories at the welds. Two reference maneuvers have been considered as loading conditions. The computed stresses have been used to assess the life of the frame according to the notch stress approach (Radaj & Seeger). The method correlates the stress range in a idealized notch, characterized by a fictitious radius in the weld toe or root, to the fatigue life by using a single S-N curve. New technical frame layouts have been proposed and verified by means of the developed finite element model. The considered approach allows to speed up the design process and to reduce the testing phase.


2018 ◽  
Vol 4 (4) ◽  
pp. 13
Author(s):  
Anand Mohan Singh ◽  
Megha Bhawsar ◽  
Neeraj Kumar Nagayach

In this present work a virtual environment has been created to investigate the failure analysis on spur gear assembly in which structural analysis, fatigue failure analysis and contact stress analysis have been performed using finite element method. For this work, a three dimensional cad model has been created and imported to ANSYS workbench for further finite element analysis. Various boundary conditions have been used to perform structural, fatigue failure assessment and contact analysis such as revolute joints is provided with Body Ground connection for 60 rpm for structure analysis, Augmented Lagrange method is set for contact analysis, for fatigue life analysis the fatigue strength factor is used as 0.85 for fully reverse loading and the life of shear stress in cycles and for the contact analysis linear and nonlinear contact are used for both source and target body. It has been observe that contact stress and bending stress not attain their maximum values at the same points, if the contact stress minimize in primary design stage then the failure of gear can minimized by analysis of the problem during the earlier stage of design. It can also be state that by using finite element analysis complex analysis like fatigue and contact analysis can be performed very accurately within a very short time and cost effectively rather than experimental analysis.


2011 ◽  
Vol 383-390 ◽  
pp. 5894-5898 ◽  
Author(s):  
Su Hong Liu ◽  
Fang Li

The stabilizer anti-roll bar can prevent the vehicle from rollover, so it is important to get the mechanical properties of it. To achieve it, the finite element technology is chosen and the parametric model was built in the first place. The von Mises stress distribution, reliability and the sensitivity were obtained after being analyzed respectively. Based on these, the fatigue life was estimated finally. The fatigue analysis results were contrasted with the life requirements of stabilizer bar’s endurance test.


Author(s):  
Barıs¸ Koca ◽  
Bu¨lent Ekici

The focus of this study is to find fatigue behavior and fatigue life of a drag link in the different road and loading conditions. Finite element method was used for fatigue analysis and fatigue life of the drag link was predicted. Firstly, the historical changes in the concept of the fatigue and fatigue life calculation methods were explained in the chapter one and two. Factor affecting the fatigue performance was explained. Stress and strain based fatigue analysis methods were described clearly. Finally, fatigue life analysis in the frequency domain which is a new method relative to the others was explained. Then, two different steering drag links of a midibus were examined and fatigue life calculations of these two drag links were made. The fatigue life analysis in the time domain of the drag links were made in the static steering conditions and the results were compared with the test results made by the vendor of the drag links. After that, the drag link which has a greater fatigue life than the other was selected, the road loads were taken from another test report which was made by using the same drag link and the fatigue life of the drag link was computed by using the finite element method in the time domain. Finally, the same road loads were converted in the frequency domain and the fatigue life analysis of the same drag link were made in the frequency domain. The results from the time domain and the frequency domain were compared and the advantages of the fatigue life analysis in the frequency domain were expressed.


Author(s):  
Bianca de Carvalho Pinheiro ◽  
Ilson Paranhos Pasqualino ◽  
Se´rgio Barros da Cunha

This work is within an ongoing study, which aims to propose a new methodology for fatigue life analysis of steel pipelines with plain dents under cyclic internal pressure. This methodology follows the current high cycle fatigue theory and employs stress concentration factors induced by plain dents to modify standard S-N curves. A previously developed and validated finite element model is extended to generate stress concentration factors for longitudinal and transverse dents, in addition to spherical dents. Several finite element analyses are carried out in a parametric study to evaluate stress concentration factors induced by the three dent types studied: spherical, longitudinal and transverse dents. Analytical expressions are developed to estimate stress concentration factors for these three dent types as function of pipe and dent geometric parameters. Small-scale fatigue tests are conducted to evaluate the finite life behavior of dented steel pipes under cyclic internal pressure. The methodology is validated in view of the fatigue tests results. Including expressions to estimate stress concentration factors for three different dent types (spherical, longitudinal and transverse dents), the proposed methodology can then be used for fatigue life analysis of dented steel pipelines under cyclic internal pressure.


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