Study on Fatigue Strength of Welding Joint in Wuhan Iron and Steel

2012 ◽  
Vol 538-541 ◽  
pp. 1492-1497
Author(s):  
Zhen Ping Fan ◽  
Xiao Wu ◽  
Qiang Li
Keyword(s):  
Finite Element ◽  
Fatigue Strength ◽  
Stress Concentration ◽  
Abrupt Change ◽  
Iron And Steel ◽  
Welding Joint ◽  
The World ◽  
Grouping Method ◽  
Weld Area ◽  
Distribution Of Stress

As abrupt change of the shape and elastic constant in the weld area occurs to the welding joint, there will be obvious stress concentration near the weld area when being loaded. Lifting and Lowering Method and Grouping Method prevailing in the world are applied to conduct an experiment about fatigue strength of a certain welding joint in Wuhan Iron and Steel and S-N curve is drawn in this paper based on the condition of nominal stress. In addition, the influence of weld size of the welding joint on the distribution of stress is studied through the calculation of finite element numeral value and experimental test. According to the factor of stress concentration, S-N curve is modified to provide the data support for the application of the welding joint and assessment of fatigue strength.

Geometric Parameters Optimization Design for Aluminum Alloy Welding Joint Based on Increasing Fatigue Strength

2011 ◽  
Vol 704-705 ◽  
pp. 1106-1111 ◽  
Author(s):  
Xue Song Liu ◽  
Ping Wang ◽  
Zhong Jie Yan ◽  
Qiang Wang ◽  
Hong Yuan Fang
Keyword(s):  
Fatigue Strength ◽  
Stress Concentration ◽  
Optimization Design ◽  
Fatigue Property ◽  
Geometric Parameters ◽  
Parameters Optimization ◽  
Tig Welding ◽  
Weld Toes ◽  
Welding Joint ◽  
Weld Toe

The geometric parameters of the welding joint had an important effect on fatigue strength, so the stress concentration of the typical double sided asymmetric V-notch joint on high speed train was calculated, the relationship between geometric parameters and the stress distribution of the welding joint was analyzed by FEM, also the geometric parameters optimization design of welding joint was proposed. According to theoretical optimization design scheme, the geometric parameters optimization adopted shaping the weld joint by manual TIG welding and processing circle arc on weld toes by milling respectively,. and the fatigue property of the welding joint optimized by different methods was tested. By comparing the experimental results, it was found that manual TIG welding was difficult to obtain the favorable weld toe angle to decrease the stress concentration, and the welding joint was softened obviously. Accordingly, it revealed that the fatigue property was lower than that of initial joint in fatigue testing. On the contrary, the radius of the weld toes circle arc can be controlled accurately by mechanical processing. The stress concentration was reduced obviously by rounding off the weld toe, as a result the fatigue strength of the welding joint could be increased remarkably. Keywords: A7N01, optimization design, geometric parameters of welding joint, FEM

Research of Fatigue Limit and Stress Concentration on Structural Steel with Double-Notches

2009 ◽  
Vol 419-420 ◽  
pp. 849-852
Author(s):  
Sheng Wu Wang ◽  
Shu Juan Sun ◽  
Ai Ling Wen ◽  
Wei Da Wang ◽  
Shinichi Nishida
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Fatigue Strength ◽  
Stress Concentration ◽  
Fatigue Limit ◽  
Three Dimensional ◽  
Fatigue Tests ◽  
Notched Specimen ◽  
Blind Hole ◽  
Element Method

The fatigue limit of parts and components that have the multi-notches is important data for the design and manufacture of machinery and traffic equipment which are operated under the high speed or pressure. In this paper the rotating bending fatigue tests have been carried out to investigate the fatigue limit of specimen with double-notch that is constructed of step and blind hole, and analyzed the effect of stress concentrations at the double-notched bottoms on the fatigue limits, using three-dimensional elastic finite element method. Firstly, the fatigue tests of 8 group specimens have been performed for examining the of fatigue limits of the single-notched specimen and double-notched specimen, respectively. Additionally, the stress field interactions between two stress fields by the blind hole notch and step are discussed using three-dimensional elastic finite element method. The main results obtained in this study are as follows: The fatigue limit of the double-notched specimen are down comparison with the fatigue limit of the single-notched specimen; the fatigue limit of the double-notch specimen is insensitive to distance between the blind hole and step for the low carbon structure steel with better ductility; for the high-strength steel, superposition and intensification of the stress concentration by the blind hole and step mutually may be avoided so that their adverse effects on the fatigue strength may be become to minimize, as take appropriate distance between the blind hole and step. The results are significant for the design of engineering design of the multi-notched parts, and the study of fatigue strength.

scholarly journals Simulation of Fatigue Failure of Rail Joint Bolts by FEA

2011 ◽  
Vol 2-3 ◽  
pp. 1035-1040 ◽  
Author(s):  
Xiao Peng Li ◽  
Hui Fan Nie ◽  
Wei Jie Yuan ◽  
Bang Chun Wen
Keyword(s):  
Finite Element ◽  
Fatigue Strength ◽  
Stress Concentration ◽  
Influencing Factors ◽  
Fatigue Failure ◽  
Impact Force ◽  
Working Life ◽  
Analysis Method ◽  
Bolt Failure ◽  
Temperature Force

It is well known that the fatigue failure of bolts can affect the performance of rail joint and the safety of train running. In this work, the influence of the bolt torque and radius of rounded root of rail bolt on the fatigue strength of the rail bolt are studied by Finite Element Contact Analysis method. And the influence effects of the wheel impact and temperature force of the rail caused by temperature changed on bolt failure are studied. The results indicate that properly torque and increasing the radius of rounded root rail bolt can reduce the stress concentration at the root of rail bolt and this will improves the fatigue strength and the working life of the rail bolt and rail joint. The repeated temperature force of the rail and wheel impact force are playing an important role in the influencing factors on fatigue failure of the rail joint bolts. Due to this, the two bolts near the rail joints will to be fatigue failure almost earlier than others. That is one of the reasons why the bolts should be preloaded or replaced regularly.

scholarly journals Fatigue Characterization on a Cast Aluminum Beam of a High-Speed Train Through Numerical Simulation and Experiments

2021 ◽  
Vol 34 (1) ◽  
Author(s):  
Weiyuan Dou ◽  
Lele Zhang ◽  
Haifeng Chang ◽  
Haifeng Zhang ◽  
Changqing Liu
Keyword(s):  
Finite Element ◽  
Fatigue Strength ◽  
Stress Concentration ◽  
High Speed ◽  
Fatigue Property ◽  
Strength Reduction ◽  
High Speed Train ◽  
Cast Aluminum ◽  
Structural Fatigue ◽  
Aluminum Beam

AbstractThe cast aluminum beam is a key structure for carrying the body-hung traction motor of a high-speed train; its fatigue property is fundamental for predicting the residual life and service mileage of the structure. To characterize the structural fatigue property, a finite element-based method is developed to compute the stress concentration factor, which is used to obtain the structural fatigue strength reduction factors. A full-scale fatigue test on the cast aluminum beam is designed and implemented for up to ten million cycles, and the corresponding finite element model of the beam is validated using the measured data of the gauges. The results show that the maximum stress concentration occurs at the fillet of the supporting seat, where the structural fatigue strength reduction factor is 2.45 and the calculated fatigue limit is 35.4 MPa. Moreover, no surface cracks are detected using the liquid penetrant test. Both the experimental and simulation results indicate that the cast aluminum beam can satisfy the service life requirements under the designed loading conditions.

Reduction of Free-Edge Stress Concentration

1985 ◽  
Vol 52 (4) ◽  
pp. 801-805 ◽  
Author(s):  
P. R. Heyliger ◽  
J. N. Reddy
Keyword(s):  
Finite Element ◽  
Stress Concentration ◽  
Finite Element Model ◽  
Three Dimensional ◽  
Element Model ◽  
Free Edge ◽  
Shear Stresses ◽  
Normal Stresses ◽  
Interlaminar Shear ◽  
Three Dimensional Elasticity

A quasi-three dimensional elasticity formulation and associated finite element model for the stress analysis of symmetric laminates with free-edge cap reinforcement are described. Numerical results are presented to show the effect of the reinforcement on the reduction of free-edge stresses. It is observed that the interlaminar normal stresses are reduced considerably more than the interlaminar shear stresses due to the free-edge reinforcement.

Stress concentration factors for the torsion of curved beams of arbitrary cross-section

2006 ◽  
Vol 220 (12) ◽  
pp. 1709-1726 ◽  
Author(s):  
R E Cornwell
Keyword(s):  
Finite Element ◽  
Stress Concentration ◽  
Cross Section ◽  
Cross Sections ◽  
Shear Stresses ◽  
Curved Beams ◽  
Finite Element Implementation ◽  
Out Of Plane ◽  
Concentration Factors ◽  
Stress Concentration Factors

There are numerous situations in machine component design in which curved beams with cross-sections of arbitrary geometry are loaded in the plane of curvature, i.e. in flexure. However, there is little guidance in the technical literature concerning how the shear stresses resulting from out-of-plane loading of these same components are effected by the component's curvature. The current literature on out-of-plane loading of curved members relates almost exclusively to the circular and rectangular cross-sections used in springs. This article extends the range of applicability of stress concentration factors for curved beams with circular and rectangular cross-sections and greatly expands the types of cross-sections for which stress concentration factors are available. Wahl's stress concentration factor for circular cross-sections, usually assumed only valid for spring indices above 3.0, is shown to be applicable for spring indices as low as 1.2. The theory applicable to the torsion of curved beams and its finite-element implementation are outlined. Results developed using the finite-element implementation agree with previously available data for circular and rectangular cross-sections while providing stress concentration factors for a wider variety of cross-section geometries and spring indices.

Atomistic Simulations of Nanoindentation on Cu (111) with a Void

2008 ◽  
Vol 33-37 ◽  
pp. 919-924
Author(s):  
Chung Ming Tan ◽  
Yeau Ren Jeng ◽  
Yung Chuan Chiou
Keyword(s):  
Finite Element ◽  
Stress Concentration ◽  
Indentation Depth ◽  
Equilibrium Configuration ◽  
Complete System ◽  
Internal Surface ◽  
Atomistic Simulations ◽  
Element Formulation ◽  
Variable Parameters ◽  
Deformed State

This paper employs static atomistic simulations to investigate the effect of a void on the nanoindentation of Cu(111). The simulations minimize the potential energy of the complete system via finite element formulation to identify the equilibrium configuration of any deformed state. The size and depth of the void are treated as two variable parameters. The numerical results reveal that the void disappears when the indentation depth is sufficiently large. A stress concentration is observed at the internal surface of the void in all simulations cases. The results indicate that the presence of a void has a significant influence on the nanohardness extracted from the nanoindentation tests.

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