Strain Rules of Cross Wedge Rolling Asymmetric Shaft-Parts Based on the Parity Wedge

2012 ◽  
Vol 201-202 ◽  
pp. 1066-1070
Author(s):  
Zhan Li ◽  
Xue Dao Shu ◽  
Wen Fei Peng ◽  
Bao Shou Sun

The analysising of strain is the key factors to understand the forming mechanism of cross wedge rolling asymmetric shaft. due to the extrusion of dies and other external force, its interior,interactions can cause the relative position between the various parts. In order to study the deformation of workpiece at different degrees, pulling in the finite element strain field analysis, the strain of the analysis at deformation process is also a necessary precondition for forming and stress distribution. In this papre,By using Deform3D platform, the forming process of the cross wedge rolling on parity wedge asymmetric shaft is simulated. It is also to be analyzed the distribution and variation of the amount of strain in the rolling process, it shows that a cross-sectional and longitudinal section about the deformation characteristics of the strain fields, the results can achieve production of cross wedge rolling and provide important theoretical foundation to promote further cross-wedge rolling.

2014 ◽  
Vol 494-495 ◽  
pp. 457-460 ◽  
Author(s):  
Bin Hu ◽  
Xue Dao Shu ◽  
Peng Hui Yu ◽  
Wen Fei Peng

The paper is based on the newest hollow railway axle, which utilizes the Pro/E designed multi-wedge cross wedge rolling (MCWR) model, utilizes the finite element analysis software DEFORM-3D to complete the numerical simulation about the whole stage of the hollow railway axle forming process, and analyzes the strain rule at the broadening stage of the hollow railway axle, especially conducts a detailed research on forming character into the strain rule at the multi-wedge transition stage, and finally gets the strain forming mechanism of the hollow railway axle at the broadening stage. The result of the research on the strain rule poses great scientific significance on enhancing the product quality and the production efficiency of the hollow railway axle, and improving the theory of multi-wedge cross wedge rolling.


2011 ◽  
Vol 381 ◽  
pp. 72-75
Author(s):  
Bin Li

This paper investigates the interfacial slip between the forming tool and workpiece in a relatively new metal forming process, cross-wedge rolling. Based on the finite elements method, three-dimensional mechanical model of cross wedge rolling process has been developed. Examples of numerical simulation for strain, stress distributions and rolling load components have been included. The main advantages of the finite element method are: the capability of obtaining detailed solutions of the mechanics in a deforming body, namely, stresses, shapes, strains or contact pressure distributions; and the computer codes, can be used for a large variety of problems by simply changing the input data.


2014 ◽  
Vol 488-489 ◽  
pp. 1125-1129
Author(s):  
Xue Dao Shu ◽  
Wen Ping Liu ◽  
Chao Cheng ◽  
Zhan Li ◽  
Wen Fei Peng ◽  
...  

In order to expand cross wedge rolling technology applications further and improving the quality of asymmetric shaft parts, this paper predicts the position of center defect location of Cross Wedge Rolling asymmetric shaft parts based on Parity Wedge by Normalized C & L criteria. On this basis, it conducted a systematic study on the effect of forming angle on quality of rolling core part. It has found that, during the forming process of Cross Wedge Rolling shaft parts, rolling center region was more prone to damage, and achieved the regularity of process parameters on the quality of core part. The study results lay the theoretical foundation for preventing defects effectively and improving quality of rolling core part.


2006 ◽  
Vol 510-511 ◽  
pp. 254-257 ◽  
Author(s):  
Hyoung Wook Lee ◽  
Geun An Lee ◽  
Duk Jae Yoon ◽  
Seo Gou Choi ◽  
Nak Kyu Lee ◽  
...  

A micro-alloyed non-heat-treated material does not need post heat treatment processes such as quenching and tempering after the forming process in production stages. This material can be called a green material since it can reduce industrial costs and harmful pollutants generated from post heat treatments. In this paper, near-net-shape forming processes were studied in order to make an automotive part using a micro-alloyed material. The cold forging technique using a former was utilized for the main shaping, and the cold incremental forming technique using a cross wedge rolling machine was adopted for the enhancement of strength and the final shaping of the part. In order to get more adequate process, the cross wedge rolling process is compared to the swaging process for the micro-alloyed steel and general carbon steels through experiments.


2012 ◽  
Vol 271-272 ◽  
pp. 406-411 ◽  
Author(s):  
Wen Yu Ma ◽  
Bao Yu Wang ◽  
Jing Zhou ◽  
Qiao Yun Li

The aim of this paper is to determine whether the train axle cross wedge rolling(CWR) using square billet as blank is available or not. Based on numerical simulation software DEFORM-3D, we built the finite element model. And the whole forming process was simulated successfully. The stress and strain distributions of workpiece in the process were analyzed. The effect of forming angle, stretching angle and billet size on rolling force was investigated, then determined the proper process parameters. The differences between the round billet rolling and the square billet rolling were obtained by comparing the tangential, axial and radial forces during the rolling process. The studied results show the availability of using square billet as blank in train axle CWR and provide important realistic meaning and application value.


2011 ◽  
Vol 101-102 ◽  
pp. 1019-1022
Author(s):  
Wen Fei Peng ◽  
Wen Wei Gong ◽  
Kang Sheng Zhang

Cross wedge rolling of asymmetric shaft parts has a series of problems such as the difficulty of forming, and the rules of mental flow are not clear until now. Rigid plastic FE models of the asymmetric rolling and symmetric rolling were adopted to analyze the difference of the stress and strain fields of cross section and vertical section in the two rolling processes, which illuminated the rules of the stress and strain fields in the asymmetric rolling process. The research of the stress and strain fields in asymmetric rolling has positive significance for recognizing the forming characteristics and predicting deformation defects in asymmetric rolling process.


2010 ◽  
Vol 154-155 ◽  
pp. 1779-1782
Author(s):  
Gui Hua Liu ◽  
Zhi Jiang ◽  
Yi Bian ◽  
Guang Sheng Ren ◽  
Chun Guo Xu

Cross wedge rolling (CWR) technology, which is a new metal forming process to produce stepped shaft in forging industry, has developed rapidly in the last decades. Tool wear is a key factor to influence products’ quality during CWR process in practice. Basing on the analysis of characteristic of the tool wear, the similar outline dimension of the worn tool in service is obtained by blocking up the end of the tool. A series of experiments are completed to research the influence of the tool wear on the center defects of the workpiece, and the available method to repair the worn tools is brought forward.


Materials ◽  
2018 ◽  
Vol 11 (8) ◽  
pp. 1278 ◽  
Author(s):  
Sutao Han ◽  
Xuedao Shu ◽  
Chang Shu

Considering problems about concaves at the stepped shaft ends, this paper established the plastic flow kinetic theories about metal deforming during the cross-wedge rolling (CWR) process. By means of the DEFORM-3D finite element software and the point tracing method, the forming process of stepped shafts and the forming mechanism of concaves at shaft ends were studied. Based on the forming features of stepped shafts, rolling pieces were designed using variable cone angle billets. Single-factor tests were conducted to analyze the influence law of the shape parameters of billet with variable cone angle on end concaves, and rolling experiments were performed for verification. According to the results, during the rolling process of stepped shafts, concaves will come into being in stages, and the increasing tendency of its depth is due to the wave mode, the parameters of cone angle α, the first cone section length n. Furthermore, the total cone section length m has an increasingly weaker influence on the end concaves. Specifically, cone angle α has the most significant influence on the quality of shaft ends, which is about twice the influence of the total cone section length m. The concave depth will decrease at the beginning, and then increase with the increasing of the cone angle α and the first cone section length n, and it will decrease with the increasing of the total cone section length m. Finite element numerical analysis results are perfectly consistent with experimental results, with the error ratio being lower than 5%. The results provide a reliable theoretical basis for effectively disposing of end concave problems during CWR, rationally confirming the shape parameters of billets with a variable cone angle, improving the quality of stepped shaft ends, and realizing the near-net forming process of cross-wedge rolling without a stub bar.


2018 ◽  
Vol 190 ◽  
pp. 11006 ◽  
Author(s):  
Zbigniew Pater ◽  
Janusz Tomczak

Rail axles are large-size parts produced in large batches. Currently, these parts are produced by metal forming techniques such as rotary forging, open die forging with hydraulic presses and open die hammer forging (minimum ram weight: 3 Mg). Nevertheless, not only are the above methods far from being efficient, they also lack accuracy (open die forging). As a result, new techniques for producing rail axles are constantly developed. One of such alternative techniques is based on the use of cross wedge rolling (CWR), which is the subject of the present study. An innovative roll design for producing rail axles by CWR is proposed. The rolls are provided with three pairs of wedge tools that act simultaneously on the workpiece and form the part in one revolution of the rolls, i.e., during 20 s. The numerical modelling of a CWR process with the proposed roll design reveals that the solution can be used to produce railway axles with the desired geometry. This technique, however, requires relatively high loads and torques. To decrease the force parameters, the forming process was modified and ran in two operations. The first operation consists in forming the central step of the workpiece while the other one involves the formation of steps on the ends of the workpiece. The results of the new simulation show a significant decrease in the loads and torques, which is caused, among others, by reducing the nominal diameter of the rolls from 1600 mm to 1200 mm. The numerical findings can be used to design a rolling mill for producing rail axles.


2017 ◽  
Vol 43 (2) ◽  
pp. 124
Author(s):  
Ivana Tanoko ◽  
Fifin L Rahmi

Introduction and Objective: Glaucoma is the leading cause of global irreversible blindness, signed by glaucomatous optic neuropathy related to visual field defect. The purpose of the study is comparing visual field defect examination using HVFA to Amsler Grid in glaucoma patient at dr. Kariadi Hospital. Methods: This is a cross-sectional study. Amsler Grid were performed to the patients who have reliable HVFA at last 6 months and presented as descriptive analytic results. Result: There were 40 eyes involved in this study from 27 patients (15 men, 12 women), 26-68 years old and visual acuity 1/60-6/6. Seventeen eyes showed visual field defect in HVFA and Amsler Grid had average MD - 24.97 dB, CDR 0.89 and RNFL thickness 51.74. We found that 11 eyes didn’t showed in both of examination had average MD -8.06, CDR 0.63 and RNFL thickness 103.23 and those parameters are significantly different to the 17 eyes before (p<0.05). Data from 12 eyes that showed visual field defect only one of examination (9 only in HVFA and 3 in Amsler Grid) didn’t show difference statistically each other. Conclusion: HFVA and Amsler Grid seemed to be comparable in detecting visual field defect in advanced glaucoma.


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