共查询到18条相似文献,搜索用时 109 毫秒
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喷丸强化会使零件表面产生残余压应力,可以提高零件抗疲劳能力。试验采用正交试验法对螺母表面进行喷丸强化,沿着螺母轴向方向取三个截面进行残余应力测试分析。试验表明喷丸强化后螺母表面的残余应力均为压应力,有利于提高螺母的抗应力腐蚀和抗疲劳能力;螺母直段截面和大圆弧截面的残余压应力分布在(400~500)MPa,大于小圆弧截面的残余压应力;通过SPSS软件对螺母不同截面以及整体残余应力分布进行显著性分析,表面喷丸流量对螺母整体残余应力分布影响较为显著,并且得出了较为优异的喷丸强化工艺参数。 相似文献
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喷丸齿轮弹流润滑特性分析 总被引:1,自引:0,他引:1
利用有限元软件Abaqus仿真得到喷丸强化后齿轮表面形貌,采用MATLAB分析喷丸强化后表面微观形貌对齿轮弹流润滑性能的影响,并与机加工表面的弹流润滑性能进行比较。结果表明:喷丸强化后齿轮的弹流润滑特性总体和机加工齿面保持一致,但喷丸处理后减少了粗糙峰对压力和膜厚的影响,齿面更容易建立起油膜,润滑状态较好;喷丸强化形成的橘皮凹坑有利于储存润滑油剂,齿轮的润滑性能得到了提高。 相似文献
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最近根据布里斯托尔静态试验弹簧联合有限公司(Associated Spring Inc., Bristol, CT.)进行的研究表明:对压缩弹簧进行适当的喷丸强化处理后,其许用应力和疲劳寿命均提高40%以上。喷丸强化后弹簧钢丝表面产生一层残余压应力,从而可改善弹簧的工作性能,延长弹簧使用寿命。喷丸强化的目的是用最大程度的压应力使金属表面获得最小的变形。在这一过程中需要控制的变量主要是喷丸时间、弹丸速度及弹丸直径。经喷丸强化处理后可大大减少由于金属表面的凹坑、刻痕、接缝等 相似文献
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作为机械表面强化技术之一,喷丸强化使工件表层发生形变硬化,引入较高的残余压应力,减少了疲劳应力作用下微裂纹的萌生并抑制其扩展,从而显著提高零件的抗疲劳断裂和抗应力腐蚀开裂的能力。基于喷丸残余应力解析计算模型,从余弦函数模型、接触应力模型和球腔膨胀模型三个方面介绍喷丸强化残余应力的产生,进而对喷丸残余应力的仿真预测及影响规律进行论述。为了提高试件疲劳强度而引入的残余压应力会带来影响形位精度的变形,基于此阐述了喷丸残余应力对疲劳性能的影响及其在疲劳过程中的演化,同时论述了喷丸残余应力变形预测及控制的研究现状,最后对喷丸残余应力未来的研究内容与发展方向进行展望。 相似文献
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The symmetrical cell model is widely used to study the residual stress induced by shot peening. However, the correlation between the predicted residual stresses and the shot peening coverage, which is a big challenge for the researchers of the symmetrical cell model, is still not established. Based on the dynamic stresses and the residual stresses outputted from the symmetrical cell model, the residual stresses corresponding to full coverage are evaluated by normal distribution analysis. The predicted nodal dynamic stresses with respect to four corner points indicate that the equi-biaxial stress state exists only for the first shot impact. Along with the increase of shot number, the interactions of multiple shot impacts make the fluctuation of the nodal dynamic stresses about an almost identical value more and more obvious. The mean values and standard deviations of the residual stresses gradually tend to be stable with the increase of the number of shot peening series. The mean values at each corner point are almost the same after the third peening series, which means that an equi-biaxial stress state corresponding to the full coverage of shot peening is achieved. Therefore, the mean values of the nodal residual stresses with respect to a specific transverse cross-section below the peened surface can be used to correlate the measured data by X-ray. The predicted residual stress profile agrees with the experimental results very well under 200% peening coverage. An effective correlation method is proposed for the nodal residual stresses predicted by the symmetrical cell model and the shot peening coverage. 相似文献
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以重型运输车车架纵梁做为研究对象,研究喷丸处理对车架焊接变形的影响.采用MSF-3M型应力分析仪测量了焊接试验件的应力,采用三坐标测量仪测量了焊接试验件的前后变形并应用Matlab软件生成试验件的三维图形,采取变形量数据的标准差对试验件的变形量进行分析.研究发现喷丸处理能够对焊接变形有明显的改善作用,喷丸处理对车架纵梁焊接变形能够有效控制. 相似文献
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喷丸三维残余应力场的有限元模拟 总被引:13,自引:1,他引:13
运用大型有限元计算软件ABAQUS建立了模拟喷丸残余应力场的三维有限元模型,预测了在相同喷丸强度下玻璃丸和钢丸两种类型弹丸喷射所产生的残余应力场。模拟过程中,分析了线性减缩积分单元的沙漏参数、材料的应变硬化率、喷丸覆盖率以及初始残余拉应力等因素对304不锈钢靶材残余应力分布的影响。从计算结果可以看出,钢丸喷丸产生的残余压应力层较深,但在高覆盖率时,玻璃喷丸产生的残余压应力的平均值比钢丸喷丸处理后产生的大。在有初始残余拉应力(250 Mpa)存在的情况下,两种类型的喷丸处理均能使304不锈钢靶材表面形成残余压应力层,这说明喷丸工艺可以提高奥氏体不锈钢焊接构件的抗应力腐蚀开裂能力。本研究成果为进一步探讨喷丸强化不锈钢焊接头抗应力腐蚀性能的机理奠定了基础。 相似文献
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Junfeng Xiang Siqin Pang Lijing Xie Guanhua Cheng Ruo Liang Feinong Gao Long Bai 《The International Journal of Advanced Manufacturing Technology》2018,97(5-8):1673-1685
This paper proposed a numerically low-cost 3D FE modeling method for multi-shot shot peening. The low computation cost and high prediction accuracy of shot peening are realized at the same time by the incorporation of random multi-shot with defined spacing between the adjacent simultaneously impinging shots, periodicity, and coverage rate of 100%. With this modeling method, one-step and dual-step multi-shot peening of 34CrNiMo6 steel target is modeled and the produced residual stress is predicted. In order to make the predicted residual stress depth profile more comparable with the measured one by XRD method, the redistribution of residual stress due to the layer removal by electrochemical polishing is simulated using Model Change technique. And the comparison between the prediction and experiment indicates that this improved 3D periodic FE modeling of multi-shot impingement provides very accurate simulation models for one-step and dual-step shot peening. It can substitute for the costly and time-consuming optimization experiments of the shot peening process, especially the multi-step shot peening process. Finally, the evolution of residual stress depth profile in dual-step shot peening process is investigated by using the simulation model and a variation of residual stress towards a more uniform distribution on the finished surface taking place in the second step is discovered by RMS analysis. 相似文献
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S.M. H-GangarajY. Alvandi-Tabrizi G.H. Farrahi G.H. MajzoobiH. Ghadbeigi 《Tribology International》2011,44(11):1583-1588
Shot peening is widely used to improve the fretting fatigue strength of critical surfaces. Fretting fatigue occurs in contacting parts that are subjected to fluctuating loads and sliding movements at the same time. This paper presents a sequential finite element simulation to investigate the shot peening effects on normal stress, shear stress, bulk stress and slip amplitude, which are considered to be the controlling parameters of fretting damage. The results demonstrated that among the modifications related to shot peening, compressive residual stress has a dominant effect on the fretting parameters. 相似文献
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Wang Jianming Liu Feihong Yu Feng Zhang Gang 《The International Journal of Advanced Manufacturing Technology》2011,56(5-8):571-578
Shot peening is a complex surface-treating process which is usually employed to improve the fatigue strength of metallic part or members. In dealing with shot peening simulation, existing literatures apply finite element method (FEM) to establish only a single shot or several shots models, thus the effect of a mass of shots impacting repeatedly and the interaction among adjacent shots are ignored. To overcome these defects of FEM models, smoothed particle hydrodynamics (SPH) coupled FEM modeling is presented, in which the shots are modeled by SPH particles and the target material is modeled by finite elements. Contact algorithm is used to simulate the interaction between shots and target. Utilizing this model, material model for shots is established, the relationships between compressive residual stress and peening frequencies, coverage, and velocities are analyzed. Steady compressive residual stress can be gotten by multiple peening; higher coverage can improve the compressive residual stress; faster velocities can induce greater and deeper maximum residual stress in target subsurface. The simulation results agree well with the existing experimental data. The study will not only provide a new powerful tool for the simulation of shot peening process, but also be benefit to optimize the operating parameters. 相似文献