共查询到20条相似文献,搜索用时 15 毫秒
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铝合金预拉伸板在成型过程中会产生较大的残余应力,在切削过程中毛坯的初始残余应力的释放对整体结构件的宏观变形有重要的影响。在弹塑性力学的基础上,综合运用Hypermesh和ABAQUS建立残余应力单因素作用下的三维铣削仿真加工变形场的有限元模型,利用生死单元技术模拟了材料的去除,分析了铝合金板材材料去除过程中残余应力释放引起的加工变形规律。并且运用Hypermesh提高了有限元前处理的速度,解决了复杂模型的残余应力加载困难与单元去除困难的问题。 相似文献
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Xiaohui Jiang Beizhi Li Jianguo Yang Xiao Yan Zuo 《The International Journal of Advanced Manufacturing Technology》2013,68(1-4):175-186
Residual stress has a sustained impact on the deformation of thin-walled parts after processing, raising the strict restrictions required in their using procedure. In general, with regard to thin-walled parts, different processing parameters will affect the distortion and residual stress generation of the workpiece, which play the key role in the machining. However, controlling the material removal rate is also quite critical to machining of thin-walled parts. In order to reach these goals, based on the relation between residual stress and uncut chip thickness (UCT), a method is proposed by optimizing the milling tool diameters. The research finding reveals that, by improving the tool diameter, at the same circular position, smaller UCT can be achieved. In addition, take 6 and 12 mm tool diameter as analysis cases; larger tool diameter can reduce the residual tensile stress distribution significantly (the ratio ranges from 13.9 to 34.7 %) and improve the material removal rate. Moreover, a typical thin-walled part is evaluated using different tool diameters (6 and 12 mm) by experiments, as the final distortion can be decreased by 60 % with 12-mm tool diameter. The distribution of machined surface and subsurface residual stress is turning to be more uniform. Hence, it proves that, under the goals of maintaining machining accuracy and material removal rate, also improving the distribution of residual stress, it is possible to achieve by controlling the UCT (tool diameters) in the processing of thin-walled. All these findings can help to enhance the milling precision of thin-walled parts, as well as control and optimize the residual stress distribution. 相似文献
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《计算机集成制造系统》2015,(9)
为探索低速盘铣钛合金时铣削参数与加工表面残余应力的关系,设计完成了铣削速度、切削深度、进给速度三因素三水平的正交实验。实验结果表明,在所选用切削参数范围内,已加工表面残余应力均表现为压应力,铣削速度的变化对其影响最显著,进给速度次之,切削深度影响最小。提出将支持向量机回归技术应用于工艺参数优化,建立了盘铣加工钛合金表面残余应力的支持向量机模型,并通过实验以及与指数型回归经验模型的对比,验证了该方法的实用性和合理性。 相似文献
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Q. Z. Zhang B. F. Shu M. B. Chen Q. B. Liang C. Fan Z. Q. Feng P. J. Verlinden 《Journal of Mechanical Science and Technology》2015,29(2):655-662
A series of simulations were carried out to investigate the residual stress induced in the photovoltaic laminate during the cooling process after lamination with a global model and several submodels. The simulations focus separately on the effects of the cooling rate, the cell layout and anisotropy on the residual stress and deformation of the photovoltaic laminate in a comparative manner with the finite element method. The results have shown that significant stress concentration and twist occurs in the interconnection region in the cell. In addition, different cooling rates, cell layouts and anisotropy only influence the largest stress rather than the stress distribution and deformation. Therefore, the results of a uniform stationary isotropic model with fewer cells can provide enough insight into the stress distribution in real photovoltaic laminates and the modified largest first principal stress can be used for design and verification. 相似文献
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Qin Meng-yang Ye Bang-yan Jia Xiong He Ai-dong 《The International Journal of Advanced Manufacturing Technology》2013,65(1-4):355-361
This paper presents an analysis and experimental study on the formation and distribution of machined surface residual stress in pre-stress cutting. In the first component of the paper, the mechanical and thermal effect on residual stress is analysed. The results show that machined harden layer and cutting heat transfer conditions are crucial to form residual stress in a machined surface. Residual stress has three kinds of distributions in different mechanical and thermal conditions: tensile stress, compressive stress and tensile–compressive stress. If pre-stress is applied, it would facilitate residual compressive stress in the machined surface effectively; its action is analysed with an experimental study. The experiment is carried out by hardened 40Cr alloy steel turning with different tool rounds and pre-stress loading; the results obtained in this study indicate that the tool round would redound to generate residual compressive stress in the machined surface and affect the residual stress distribution significantly, whilst pre-stress load can affect the magnitude of residual stress actively, but does not for its distribution. It is found that the experimental results of residual stress distribution are consistent with the theoretical analysis. 相似文献
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Xiaohui Jiang Beizhi Li Jianguo Yang XiaoYan Zuo Kang Li 《The International Journal of Advanced Manufacturing Technology》2013,66(9-12):1439-1448
In the rapid development of the modern high-speed milling industry, particularly in the aerospace field, machined residual stress is an important evaluation indicator of the quality, and whether it can be controlled or not is critical. In this article, experimental data of residual stress in feed direction and vertical feed direction validated with finite element (FE) simulation, which resulted in the finding that residual stress distribution is nonuniform in varied machined circular areas. The maximum residual tensile stress in different directions changes with coordinates. It is well known that uncut chip thickness (UCT) will influence the cutting force and temperature, but the relation between UCT and residual stress is still difficult to understand and explicate. Traditional measurement of residual stresses in the feed and vertical feed direction is difficult to explain. Based on the UCT model which is a function of feed rate and tool diameter, by measuring residual tangential and radial stress, it is observed that residual tangential stress is influenced by the UCT. Moreover, residual radial stress, under high feed rate, is distributed with wave change, and residual radial stress under smaller feed rate is still affected by the UCT. These results indicate that it is possible to optimize the residual stress distribution by controlling UCT (feed rate and tool diameter) with high-speed milling. 相似文献
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提出了一种非简化的多齿圆周铣削几何运动模型,该模型考虑进给速度对刀齿运动轨迹的影响,发现在多齿圆周铣削中存在残留面积的现象,并推导出计算残留面积高度的公式,公式表明多齿圆周铣削的残留面积高度与刀具齿数、每齿进给量和刀具半径有关;然后以残留面积高度公式为基础,利用Visual C++(MFC)为平台开发出计算和辅助分析残留面积高度的系统;最后采用Matlab仿真软件验证非简化模型的合理性和在多齿圆周铣削中存在残留面积. 相似文献
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Modeling of residual stresses in milling 总被引:1,自引:0,他引:1
Jiann-Cherng Su Keith A. Young Kong Ma Shesh Srivatsa John B. Morehouse Steven Y. Liang 《The International Journal of Advanced Manufacturing Technology》2013,65(5-8):717-733
A model to predict residual stresses produced from milling is presented. It uses process conditions as inputs and predicts surface and subsurface residual stress profiles due to milling. The model formulation incorporates cutting force and cutting temperature predictions and utilizes those parameters to define the thermomechanical loading experienced by the workpiece. Model predictions are compared with published experimental data for both cutting forces and residual stress profiles. The results show that the model performs well in predicting residual stress trends for various milling conditions. Residual stress magnitudes as well as profiles are well predicted with the modeling approach. 相似文献
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Hyeong-Yeon Lee Jong-Bum Kim Jae-Han Lee Kamran M. Nikbin 《Journal of Mechanical Science and Technology》2006,20(3):335-344
A comprehensive review of through thickness transverse residual stress distributions in a range of as-welded and mechanically
bent components made up of a range of steels has been carried out, and simplified generic transverse residual stress profiles
for a plate and pipe components have been proposed. The geometries consisted of welded pipe butt joints, T-plate joints, tubular
T-joints, tubular Y-joints and a pipe on plate joints as well as cold bent tubes and pipes. The collected data covered a range
of engineering steels including ferritic, austenitic, C-Mn and Cr-Mo steels. Measured residual stress data, normalised with
respect to the parent material yield stress, has shown a good linear correlation versus the normalised depth of the region
containing the residual stress resulting from the welding or cold-bending process. The proposed simplified generic residual
stress profiles based on the mean statistical linear fit of all the data provides a reasonably conservative prediction of
the stress intensity factors. Whereas the profiles for the assessment procedures are fixed and case specific, the simple bilinear
profiles for the residual stresses obtained by shifting the mean and bending stress from the mean regression line have been
proposed and validated. 相似文献
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We introduce a method to measure the equivalent residual stresses and depths of the affected layers, which are generated in the workpiece during the milling process. These layers lie immediately under the milled surface. After machining, two material layers on the opposite side from the machined surface were chemically removed, and strain changes on the machined surface were measured after each layer removal. Based on the strain changes and the thickness of each removed layer, the equivalent residual stresses and depths of the affected layers in different directions were obtained. Based on the measured results, the corresponding deformations caused by the milling induced residual stresses can be predicted in workpieces with different rigidities. The predicted deformations were validated by the experimental results. We found that our measuring method can be successfully used in practice to evaluate the machined surface properties and predict the deformations caused by milling induced surface residual stresses accurately. 相似文献