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材料性能波动下TA18钛管绕弯回弹行为 总被引:2,自引:0,他引:2
以航空航天用去应力退火TA18(Ti-3Al-2.5V)钛管为对象,通过对不同来源、不同规格的钛管整管单拉试验,获得了该高强钛管的显著材料性能波动范围;基于显/隐式结合有限元算法所建立的钛管数控绕弯-回弹全过程有限元模型,阐明了弹性模量、屈服强度、硬化指数和厚向异性指数波动下高强钛管回弹的显著的线性和非线性行为,与显著工艺参数对高强钛管数控弯曲回弹的影响规律进行了对比,进而获得了材料参数波动下高强钛管回弹对截面扁化的影响规律。 相似文献
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Effects of Cross-Sectional Ovalization on Springback and Strain Distribution of Circular Tubes Under Bending 总被引:1,自引:0,他引:1
Springback and cross-sectional ovalization are two important defects in the bending formation of tubular parts. In this article, an analytic model considering ovalization is presented to calculate the springback and tangential strain in tube bending. Compared with the calculation neglecting ovalization, the proposed model could better predict the trends of springback angle over bending radius ratio and wall thickness ratio. Moreover, calculation of the tangential strain indicates that the bending deformation is more severe in the middle than at the ends of a bent tube. Through comparison of the results of this model and the calculations neglecting ovalization, it is shown that the effects of ovalization on springback are negligible only if the bending radius ratio and the wall thickness ratio are large enough. Also, the influence of ovalization differs a lot from one material to another. 相似文献
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TA18高强钛管数控弯曲回弹工艺参数影响的显著性分析 总被引:3,自引:0,他引:3
高强钛管数控弯曲卸载后会产生显著回弹现象,这严重影响着管件的几何和形状精度。基于ABAQUS平台建立了TA18高强钛管数控弯曲、抽芯及回弹三维弹塑性有限元模型,并进行可靠性评估。通过虚拟正交试验,研究工艺参数对TA18高强钛管数控弯曲回弹的影响显著性及规律。结果表明,影响回弹的显著工艺参数依次为:芯棒伸出量、弯曲模-管子摩擦系数、压块-管子间隙、压块相对助推速度和芯棒-管子间隙;其影响规律为回弹角随芯棒伸出量的增大而减小,随弯曲模-管子摩擦系数、压块-管子间隙和芯棒-管子间隙的增大而增大,当压块相对助推速度小于1时,回弹角明显增大。并采用多元逐步线性回归方法建立了回弹角与显著工艺参数之间的预测模型,经对比验证,对于规格为φ12mm×t1mm×R36mm的TA18高强钛管,此模型预测结果与虚拟试验结果之间误差不超过5%。 相似文献
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This work aims at studying the influence of lubrication on springback in air bending of interstitial free steel sheets with three different orientations namely 0°, 45°, and 90° for the bending analysis. It is observed that lubrication on both punch and die shows the lowest springback compared to the dry conditions. The white grease is more effective in reducing the springback compared to dry and SAE30 oil. A statistical analysis was done to find out appropriate deviation of springback obtained from the experiments and from the material model. It is further noted that the springback exhibited a second-order polynomial relationship with the bend angle. 相似文献
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通过ABAQUS有限元显/隐式方法模拟研究了不同芯棒和压块参数下回弹对TA18高强钛管壁厚减薄及截面畸变的影响。结果表明:在不同的工艺参数下TA18高强钛管卸载回弹后,壁厚减薄率与回弹前的相对差均小于10%;但截面畸变率与回弹前的相对差除极个别测量点外,均大于35%,甚至超过60%,且回弹后截面畸变率稳定变形区的"平台"现象消失。 相似文献
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弯曲工艺中,影响弯曲回弹角的因素很多,难以建立准确的弯曲回弹预测模型.将模糊聚类算法和统计学理论相结合,建立了弯曲回弹的模糊聚类预测模型.对V形件的弯曲回弹进行了预测并对预测结果进行了分析,预测结果符合实际实验弯曲回弹趋势,说明了模糊聚类算法的科学性及合理性. 相似文献
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以国际板材成形数值模拟会议(Numisheet2011)上提出的第四个标准考题为研究对象,应用JSTAMP/NV软件对高强度钢板DP780的弯曲及回弹过程进行仿真。通过仿真对比了板材在有无加载预应变两种情况下的回弹,分析预应变对U形冲压件回弹的影响,并将仿真结果与实验结果进行了对比,结果显示仿真结果与实验结果具有良好的匹配性。 相似文献
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以V型件弯曲和回弹过程为分析研究对象,通过对V型件弯曲及回弹过程的有限元数值模拟,分析获得了成形参数对V型件弯曲回弹的影响规律。结果表明:回弹角随弯曲角及材料的硬化系数的增大而增大,随材料的变形程度及硬化指数的增大而减小。 相似文献
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通过对弯曲回弹的讨论,建立了一个弯曲回弹调节的试验模具模型。在该模型中,先在能进行弯曲回弹调节的模具上对回弹量加以调节,并确定该材料的回弹值,然后再进行模具设计,这样可提高模具设计的精度。 相似文献
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回弹严重影响产品的成形质量和尺寸精度,特别是近年来高强度钢板的广泛使用,回弹问题更为突出.基于ABAQUS软件,建立了仿真模型.利用混合算法对板材弯曲及镦粗后的成形进行了模拟,得到了可接受的准静态解答,分析了板材成形后的应变分布、增厚量、回弹.这些对实际应用具有很好的指导和参考价值. 相似文献
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《金属学报(英文版)》2017,(5)
3-Roller bending is a widely applied manufacturing process, particularly in structural steel pipe industry.However, due to the difficulty and high cost of measuring stress distribution inside sheet material via traditional method,internal stress/strain response during forming is largely unexplored. The focuses of this study are two:(1) to map the radii of curvature as well as the stress inside the work piece during forming by utilizing the meshing mechanism of finite element method, and(2) to further provide some numeric guidelines for the configuration of the rolling system in order to improve production efficiency and product quality. The results of this study indicate that:(1) it is crucial to properly choose forming parameter in order to produce product with desired radii;(2) much like a gradual springback process, the radii of curvature gradually increase from the top roller to the exit-side bottom roller;(3) under the assumptions made in this study, to produce pipes with a specified diameter with varying configurations of the 3-roller system will not significantly change the final residual stress; and(4) finally, shifting of the neutral axis up to 2.0% of the thickness toward the compressing side during the forming process is observed. 相似文献