Numerical Study of the Workpiece Rotation Effect on the Strain and Residual Stress Distribution in the Cold Radial Forging Process

Author(s):  
H. Afrasiab ◽  
M. R. Movahhedy

Radial forging is an open die forging process used for reducing the diameters of shafts, tubes, stepped shafts and axels, and for creating internal profiles in tubes. In this study, the effect of the workpiece rotation (the circumferential feed) on the strain and residual stress distribution in the inner surface of the tube in the cold radial forging process is investigated using nonlinear three dimensional finite element modeling. To verify the model, the predicted radial forging load is compared with the published experimental data which shows a good agreement. It is shown that for achieving a more favorable residual stress distribution in the workpiece inner surface, the rotation angle associated with each stroke should be reduced. Furthermore, a total rotation angle of 90° seems to be sufficient for finalizing the strain and residual stress distribution in the workpiece inner surface and using additional rotation is just a waste of time and energy in this respect.

2007 ◽  
Vol 345-346 ◽  
pp. 1469-1472
Author(s):  
Gab Chul Jang ◽  
Kyong Ho Chang ◽  
Chin Hyung Lee

During manufacturing the welded joint of steel structures, residual stress is produced and weld metal is used inevitably. And residual stress and weld metal influence on the static and dynamic mechanical behavior of steel structures. Therefore, to predict the mechanical behavior of steel pile with a welded joint during static and dynamic deformation, the research on the influence of the welded joints on the static and dynamic behavior of steel pile is clarified. In this paper, the residual stress distribution in a welded joint of steel piles was investigated by using three-dimensional welding analysis. The static and dynamic mechanical behavior of steel piles with a welded joint is investigated by three-dimensional elastic-plastic finite element analysis using a proposed dynamic hysteresis model. Numerical analyses of the steel pile with a welded joint were compared to that without a welded joint with respect to load carrying capacity and residual stress distribution. The influence of the welded joint on the mechanical behavior of steel piles during static and dynamic deformation was clarified by comparing analytical results


2022 ◽  
Author(s):  
Saeed Darki ◽  
Evgeniy Yurevich Raskatov

Abstract In this study, considering all the parameters in radial forging and a three-dimensional model has been simulated using the finite element method. By implementing an elastoplastic state for the specimen tube, parameters such as friction type, residual stress distribution, effective strain distribution, material flow velocity and its effect on the neutral plate and the distribution of force in the die have been studied and analyzed. The effects of angle on the quality and characteristics of the specimen and the longevity of the die have also been obtained. Experimental results have been used to confirm the accuracy of the simulation. The results of the hardness test after forging were compared with the simulation results. Good agreement between the results indicates the accuracy of the simulation in terms of hardness. Therefore, this validation allows confirming the other obtained results for the analysis and prediction of various components in the forging process. After the validation and confirmation of the results through the hardness test, the hardness distribution was obtained by considering temperature changes and the effective strain on the specimen.


1989 ◽  
Vol 33 ◽  
pp. 353-362 ◽  
Author(s):  
Masanori Kurita ◽  
Makoto Sato ◽  
Ikuo Ihara ◽  
Akira Saito

AbstractCeramics are sometimes bonded to ductile metals in order to make up for their brittle behavior for industrial use. The residual stress will be induced in ceramics bonded to metals at high temeprature, and it has a strong influence on the strength of ceramic-metal joints. A silicon nitride plate was bonded to a carbon steel plate by brazing to a copper sheet sandwiched between the two materials. The residual stress distribution of the joint specimen was determined by x-ray diffraction using the Gaussian curve method. The measured residual stress distribution almost agreed with that calculated by the three-dimensional thermoelastoplastic stress analysis using FEM, but differed remarkably from that calculated by the two-dimensional stress analysis. This is because a stress concentration occurs at the ceramic-metal interface and the stress distributes three - dimensionally. The stress σx in the axial direction on the surface of the specimen takes maximum values at the center and the edge of the interface.


2010 ◽  
Vol 154-155 ◽  
pp. 593-596 ◽  
Author(s):  
Xiang Ru Liu ◽  
Xu Dong Zhou

The numerical thermal mechanical simulation of radial forging process of C45 steel stepped shaft with GFM forging machine was carried out by three dimensional finite element method DEFORM 3D. According to effective plastic strain, mean stress and mean plastic strain distribution of the radial forging process, the forging penetration efficiency (FPE) was studied throughout. The results show that: effective plastic strain in the center of the forging is never be zero; The mean stress in the center of the workpiece is proposed to describe hydrostatic pressure in this paper. There is compressive strain layer beneath the surface of the workpiece, while there is tensile strain layer in the center of the forging. These studied results could be a valuable reference for designing the similar forging operations.


2014 ◽  
Vol 996 ◽  
pp. 506-511
Author(s):  
Intissar Frih ◽  
Pierre Antoine Adragna ◽  
Guillaume Montay

This paper presents a study on the application of the finite element methods to predict the influence of a defect on the residual stress distribution in a T-welded structure. A defect is introduced in a numerical model firstly without residual stress to see its impact (size and position) on the stress distribution. Secondly the most critical defect (determined previously) is simulated with a residual stress gradient. The obtained results are useful for computation stress concentration factor due to weld residual stresses.


Author(s):  
Bai-Qiao Chen ◽  
C. Guedes Soares

This work investigates the temperature distribution, deformation and residual stress in steel plates as a result of different sequences of welding. The single-pass gas tungsten arc welding process is simulated by a three dimensional nonlinear thermo-elasto-plastic approach. It is observed that the distribution of residual stress varies through the direction of plate thickness. It is concluded that the welding sequence affects not only the welding deformation but also the residual stress mainly in the lower layer of the plates. An in-depth discussion on the pattern of residual stress distribution is presented, especially on the width of the tension zone. Smaller residual tension zone and slightly lower compressive stress are found in thicker plate.


Author(s):  
Mithun K. Dey ◽  
Dave Kim ◽  
Hua Tan

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.


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