共查询到19条相似文献,搜索用时 109 毫秒
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为了研究材料去除过程中残余应力所引起的加工变形,采用试验测量和有限元模拟方法对含有已知残余应力情况的矩形板加工的变形规律进行了研究.试验与仿真结果表明,实测变形规律与有限元解获得极好的吻合,从而为提出减小变形的技术措施奠定了基础. 相似文献
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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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为了深入研究加工工艺对连杆变形的影响,首先采用生死单元方法,基于不同工艺阶段连杆的几何形状建立相应的有限元模型。其次,针对不同工序顺序、回火温度、以及约束方式下的平行度和基本尺寸的影响进行分析,获得加工变形最小的加工工艺方案。最后,基于最优方案对连杆的残余应力与变形分布进行研究。结果表明:当加工工序为铣两平面、钻小头孔、锯开连杆、装配和车大头孔,回火温度为640℃,约束方式为小头孔时,平行度误差最小;回火温度对连杆的基本尺寸影响较大,而约束方式和工序顺序影响较小;加工完成后,连杆内部为拉应力,表面为压应力且最大变形出现在大头孔处。 相似文献
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焊接过程会产生残余应力,铣削加工后焊接残余应力释放和重新分布对铣削变形产生很大影响.为了研究残余应力释放和重新分布规律,采用有限元方法以最小焊接残余应力作为初始应力对铣削加工进行了数值模拟,获得了焊接试验件铣削加工残余应力和变形,并对焊接残余应力释放和重新分布以及加工变形进行了分析. 相似文献
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残余应力对航空整体结构件加工变形的影响分析 总被引:9,自引:0,他引:9
基于理论计算和有限元模拟,研究了毛坯的初始残余应力对大型整体结构件数控加工变形的影响,对单向 应力作用的矩形截面梁在剥层过程中的变形挠度值进行了求解。结果表明,理论解与有限元计算值是一致的。面 向工程应用,采用ABAQUS有限元软件模拟了残余应力对隔框类整体结构件加工变形的影响,并进行了试验验证。 有限元仿真结果与试验数值非常吻合。最后,根据工件加工变形的有限元模拟结果,提出了提高整体结构件制造 精度的工艺措施。 相似文献
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基于ALE(Arbitrary Lagrange-Euler)网格划分方法建立了椭圆振动切削有限元仿真模型,模拟了椭圆振动切削过程中切削力的变化规律,并将模拟获得的切削力平均值与相同工艺参数下Kim等人[1]所做的超声椭圆振动切削V型槽实验获得的切削力平均值比较,验证了有限元模型的正确性。利用建立的二维有限元模型模拟了椭圆振动切削和普通切削表面残余应力的分布情况,对比结果表明,采用椭圆振动切削的工件已加工表面在一定深度内形成了分布均匀的表面残余压应力,而普通切削情况下工件已加工表面并没有形成有效的残余压应力,从而预测了椭圆振动切削不仅能够降低切削力、延长刀具使用寿命,还对提高工件表面完整性、增强疲劳寿命和抗腐蚀能力等具有显著的作用。 相似文献
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介绍了在CAK 5085dj数控车床上,利用KISTLER 9257B对切削力进行实测,并与切削力经验公式和MATLAB神经网络预测模型所得的切削力进行比较,得出最符合实际的切削力预测模型,实现对切削力的快速精确预测;实测了数控车床刚度,估算了工艺系统受力变形误差,并将此预测结果应用到车削加工仿真中. 相似文献
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《Wear》2006,260(1-2):128-139
To study the finishing mechanism of abrasive flow machining (AFM), theoretical model of forces acting on a single grain has been developed. An experimental research has been carried out by measuring the axial force, radial force and active grain density during the AFM process. Results obtained from theoretical model for grain–workpiece interaction during material deformation have been compared with the experimental data of force and active grains obtained during AFM. Scratching experiments have also been carried out to study the mechanism of material removal during the AFM process. The conclusions arrived by the analysis about the presence of rubbing and ploughing is in agreement with the experimental AFM and scratching results. 相似文献
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A. V. Korolev E. V. Mukhina A. A. Korolev O. Yu. Davidenko B. M. Iznairov A. N. Vasin A. F. Balaev A. S. Yakovishin A. A. Mazina A. D. Sidorenko S. A. Savran V. V. Konovalov 《Russian Engineering Research》2016,36(12):1054-1055
Experimental data are presented regarding the influence of residual deformation after abrasive machining and centrifugal finishing on ball-bearing assembly. 相似文献
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Yu Wei X. W. Wang 《The International Journal of Advanced Manufacturing Technology》2007,33(3-4):260-265
Aerospace thin-walled parts have a complex structure and high accuracy. Factors such as original residual stress, fixing,
and machining may make low-rigidity parts deform easily, which is difficult for traditional craftwork to forecast and control.
Especially in machining big aerospace parts, original residual stress has a great effect on machining deflection. In this
paper finite element model of original residual stress is established to analyze the corresponding deflection by machining
aerospace thin-walled parts. Simulation results are validated consistent with experimental results approximately. At last
the paper puts forward the corresponding mend methods to control the deflection caused by original residual stress during
the actual machining process. 相似文献
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基于UG NX6.0的整体叶轮数控加工仿真研究 总被引:1,自引:1,他引:1
针对整体叶轮数控加工的特点和难点,本文系统地提出了基于UG NX6.0的数控加工仿真方案和步骤,应用UG NX6.0对整体叶轮进行数控加工刀具轨迹仿真,成功获得无干涉刀具轨迹、实体仿真结果和五轴数控加工的NC程序. 相似文献
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Xia Ji Xueping Zhang Steven Y. Liang 《The International Journal of Advanced Manufacturing Technology》2014,70(9-12):2159-2168
Residual stress is one of the critical characteristics for assessing the surface integrity of machined components as it poses a strong bearing on the service quality, functionality, and life of the machined components. The machined-in residual stresses can be affected by cutting parameters, tool geometry, material properties, and lubrication conditions. A physics-based relationship between residual stresses and processing conditions could support process planning in achieving desirable part quality and functionality. This paper presents an analytical model that predicts the residual stresses in machining under minimum quantity lubrication (MQL) condition as functions of cutting parameters, tool geometry, material properties as well as MQL application parameters. Both the lubrication and cooling effects caused by MQL air–oil mixture contribute to changes in friction due to boundary lubrication as well as changes in the thermal stress due to heat loss. The cutting force and cutting temperature are coupled into a thermal–mechanical model which incorporates the kinematic hardening and strain compatibility to predict the resulting residual stress under lubricated conditions. The residual stress prediction model is verified for orthogonal tube facing of TC4 alloy. The predicted residual stresses captured the measured results well in terms of the trend and magnitude. 相似文献