Optimization of the Clamping Scheme of the Aero Monolithic Component Based on Even-Bedded Residual Stress Distribution

2006 ◽  
Vol 532-533 ◽  
pp. 757-760
Author(s):  
Dong Lu ◽  
Jian Feng Li ◽  
Jie Sun ◽  
Bo Xin
Keyword(s):  
Residual Stress ◽  
Stress Distribution ◽  
Material Removal ◽  
Element Model ◽  
Residual Stress Distribution ◽  
The Relationship ◽  
Clamping Sequence ◽  
Chip Removal ◽  
Monolithic Component ◽  
Main Factor

Uneven distribution of the residual stress is the main factor causing the distortion of a workpiece. Different clamping scheme may cause different clamping stress. Clamping stress coupling with the residual stress inside the part induces different stress distribution, which affects components’ machining distortion and service life. To reflect the relationship between clamps and residual stress , finite element model with different clamping schemes were bulit and the clamping process was simulated. And the chip removal effect was taken into account using a material removal approach based on element death technique. Stress distribution in the workpiece is analyzed and compared under different clamping conditions. It is verified that clamping position has a significant effect on the residual stress. Otherwise the clamping sequence has a little effect on the stress redistribution.

Residual stress distribution in built-in beams

2020 ◽  
pp. 146442072095861
Author(s):  
FA de Castro ◽  
Paulo P Kenedi ◽  
LL Vignoli ◽  
I I T Riagusoff
Keyword(s):  
Residual Stress ◽  
Finite Element ◽  
Stress Distribution ◽  
Cross Section ◽  
Cross Sections ◽  
Element Model ◽  
Residual Stress Distribution ◽  
Concentrated Load ◽  
Load Growth ◽  
Final Failure

Metallic hyperstatic structures, like beams, submitted to excessive loads, do not fail completely before fully yielding in more than one cross section. Indeed, for built-in beams, three cross sections must be fully yielded before the final failure can occur. So, modeling the evolution of the cross-section residual stress distribution is an important subject that should be addressed to guarantee the stress analysis modeling correctness. This paper analyses the residual stress distribution evolution, in critical cross sections, of built-in beams during a transversal concentrated load growth, until the final failure through hinges formation. A finite element model is also presented. The results show good matches with the numerical model, used as a reference.

Effect of Friction on Residual Stress Distribution Induced by Split Sleeve Cold Expansion Process

2020 ◽  
Author(s):  
Mithun K. Dey ◽  
Dave Kim ◽  
Hua Tan
Keyword(s):  
Residual Stress ◽  
Finite Element ◽  
Stress Distribution ◽  
Compressive Residual Stress ◽  
Three Dimensional ◽  
Element Model ◽  
Residual Stress Distribution ◽  
Expansion Process ◽  
Cold Expansion ◽  
Three Dimensional Finite Element

Abstract Residual Stress distribution and parametric influence of friction are studied for the split sleeve cold expanded holes in Al 2024 T351 alloy, by developing a three-dimensional finite element model of the process. Fastener holes in the alloy are necessary for the manufacturing process, but they create a potential area for stress concentration, which eventually leads to fatigue under cyclic loading. Beneficial compressive residual stress distribution as a result of the split sleeve cold expansion process provides retardation against crack initiation and propagation at the critical zones near hole edges. In this parametric study, the influence of friction between contact surfaces of the split sleeve and mandrel is numerically investigated. Hole reaming process after split sleeve cold expansion is often not discussed. Without this post-processing procedure, split sleeve cold expansion is incomplete in practice, and its purpose of providing better fatigue performance is invalidated. This study presents results and an overview of the significance of friction with the consideration of the postprocessing of split sleeve cold expansion. The numerical results show that with increasing friction coefficient, compressive residual stress reduces significantly at the mandrel entry side, which makes the hole edge more vulnerable to fatigue. The different aspects of finite element modeling approaches are also discussed to present the accuracy of the prediction. Experimental residual stress observation or visual validation is expensive and time-consuming. So better numerical prediction with the transparency of the analysis design can provide critical information on the process.

scholarly journals Effect of cold expansion on fatigue life of double lap structure

2021 ◽  
Vol 39 (1) ◽  
pp. 189-196
Author(s):  
Hang Peng ◽  
Jianbo Qin ◽  
Tianjiao Zhao
Keyword(s):  
Residual Stress ◽  
Finite Element ◽  
Fatigue Life ◽  
Stress Distribution ◽  
Simulation Analysis ◽  
Element Model ◽  
Residual Stress Distribution ◽  
Cold Expansion ◽  
Before And After ◽  
Hole Making

The finite element simulation analysis was used to determine the weak parts of the fatigue life of a double lap structure, for which the cold expansion finite element model was established. The effect of the cold expansion of slotted bushings on the residual stress distribution around the hole of the double lap structure under different interferences was deeply studied, and the optimal interference amount was determined to be 2.5%. The effect of reaming on the residual stress distribution around the hole was studied. The residual stress distribution around the edge of the hole under actual loading conditions before and after cold expansion was compared to provide a theoretical analysis basis for extending the fatigue life of the specimen after cold expansion. The China-made and free- forged 7A85 aluminum alloy specimen was used to obtain the fatigue life and DFR value of the double lap structure after ordinary hole making and the cold expansion of slotted bushing. The results show that the fatigue life under 95% confidence and 95% reliability after cold expansion strengthening increases by about 49% and that the tested DFR value increases by about 9.8%.

scholarly journals Experimental Measurement of Residual Stress Distribution in Rail Specimens Using Ultrasonic LCR Waves

2021 ◽  
Vol 11 (19) ◽  
pp. 9306
Author(s):  
Young-In Hwang ◽  
Geonwoo Kim ◽  
Yong-Il Kim ◽  
Jeong-Hak Park ◽  
Man-Yong Choi ◽  
...  
Keyword(s):  
Residual Stress ◽  
Stress Distribution ◽  
Residual Stresses ◽  
Stress Measurement ◽  
Residual Stress Distribution ◽  
Material Surface ◽  
Arrival Times ◽  
Effective Depth ◽  
The Difference ◽  
The Relationship

Longitudinal critically refracted (LCR) waves are considered bulk longitudinal waves and penetrate into an effective depth beneath the surface parallel to the material surface. Such LCR waves can be employed to measure residual stresses because the acoustoelastic effect is the basis for ultrasonic residual stress measurements. This effect is described by the relationship between change of wave travel time and stress applied when such waves propagate in a stressed medium. In this paper, stresses applied in a rail were evaluated by using a developed LCR probe. With this transducer, it was verified how the difference in the arrival times of the LCR waves showed a trend as the tensile stresses increased. The acoustoelastic coefficients were calculated using the relationship between the stresses and the travel times, and the residual stresses of the used rails were measured using these coefficients. In addition, the difference in residual stress distribution according to the characteristics of the wheel-rail contact surface was analyzed from the obtained residual stress value. It was concluded that this non-destructive evaluation technique using LCR waves could be employed for accurate stress measurement of rails because differences in stress applied to the rail can be detected.

X-Ray Measurement for Residual Stress in Cold Ring Rolling

2010 ◽  
Vol 37-38 ◽  
pp. 1647-1650 ◽  
Author(s):  
Zhi Jiang Zuo ◽  
Wu Xin Yu ◽  
Jun Jie Yang
Keyword(s):  
Residual Stress ◽  
Finite Element ◽  
Stress Distribution ◽  
Measurement Method ◽  
Element Model ◽  
Residual Stress Distribution ◽  
Ring Rolling ◽  
X Ray ◽  
Cold Ring Rolling ◽  
The Finite Element Model

The residual stress in cold rolling could decrease the accuracy of ring parts. Because many factors could cause residual stress, it’s difficult to calculate it theoretically. At present, a measurement method was generally used to study the residual stress. For example, X ray could be used to measure residual stress in rings. Through the measurement of residual stress, it could not only obtain the residual stress level after ring rolling, but also validate the finite element model to predict the residual stress distribution. However, because the ring surface was circle, it needs to cut a plane for X ray measure, and it increases measurement inaccuracy. This method only could be suited for qualitative analysis of residual stress in cold ring rolling, and it is not suitable for quantitative analysis of residual stress distribution.

Numerical Simulation of Tube-Plate Welding Structure with T-Shaped Sections

2014 ◽  
Vol 1061-1062 ◽  
pp. 475-480
Author(s):  
Rong Han ◽  
Yi Guo Song ◽  
Dian Tao Zhang ◽  
Ren Fu Wang ◽  
Yu Feng Zheng ◽  
...  
Keyword(s):  
Residual Stress ◽  
Finite Element ◽  
Stress Distribution ◽  
Finite Element Model ◽  
Axial Direction ◽  
Element Model ◽  
Residual Stress Distribution ◽  
Computational Time ◽  
Tube Plate ◽  
Complex Shapes

At present, the finite element method (FEM) is used to predict the residual stress distribution of the welding structure. A long computational time is required for the multi-pass welding structure with complex shapes. Therefore, it is necessary to develop time-effective finite element model and computational approaches. In this study, the suitable finite element model is developed to perform the thermal and mechanical analyses for obtaining residual stress data of the tube-plate welding structure with T-shaped sections. The results of the finite element analyses show that the residual stress distribution and radial, hoop and axial direction stress distribution of the welding structure.

Modelling Fatigue Crack Growth in a Residual Stress Field

2006 ◽  
Author(s):  
A. J. Price ◽  
P. Tsakiropoulos ◽  
M. R. Wenman ◽  
P. R. Chard-Tuckey
Keyword(s):  
Fracture Toughness ◽  
Residual Stress ◽  
Fatigue Crack ◽  
Stress Distribution ◽  
Stress Field ◽  
Crack Growth ◽  
Nuclear Reactor ◽  
Element Model ◽  
Residual Stress Distribution ◽  
Residual Stress Field

Tensile residual stresses can have a detrimental affect on the safe operating limits of components. In most cases, these residual stress fields can be relieved through various treatments but in many cases it is not realistic to expect the complete elimination of these stresses. When considering the Reactor Pressure Vessel (RPV) located within a Nuclear Reactor Plant (NRP), knowledge of fatigue and fracture within a residual stress field is essential in support of safety cases. This research has investigated the behaviour of flaws that lie within a residual stress field with emphasis on fracture toughness through a series of fracture toughness tests. Alongside this experimental series, a finite element model has been created to predict the stress distributions prior to fracture. To enable an accurate simulation of the residual stress field distribution before loading to fracture it is important that the introduction of a fatigue crack is accurately modelled. This paper details several methods of introducing a fatigue crack into a simulation. During this research it has been shown that the introduction of a crack in progressive stages will lead to a better representation of the residual stress distribution prior to fracture. It has been shown that it is essential to use experimentally determined crack front shapes for the final stage of crack growth as this shape can significantly alter the residual stress distribution.

Numerical Simulation of Residual Stresses in a Spot Welded Joint

2003 ◽  
Vol 125 (2) ◽  
pp. 222-226 ◽  
Author(s):  
Xin Long ◽  
Sanjeev K. Khanna
Keyword(s):  
Residual Stress ◽  
Stress Distribution ◽  
Welded Joint ◽  
Physical And Mechanical Properties ◽  
Element Model ◽  
Residual Stress Distribution ◽  
Temperature Dependent ◽  
Welded Steel ◽  
Good Agreement ◽  
Spot Welded

An incremental and thermal-electro-mechanical coupled finite element model has been presented in this study for predicting residual stress distribution in a spot welded steel joint. Approximate temperature dependent material properties, including physical and mechanical properties, have been considered. The spot nugget shape and the residual stress distribution were obtained by simulation. The results obtained have been compared with experimental measurements, and good agreement is observed. The highest tensile residual stress occurs at the center of the nugget and the residual stress decreases towards the edge of the nugget.

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