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李萍解修明汪会干严思梁薛克敏 《中国有色金属学报》2021,(4):847-857
本文为研究Ti55合金板材电辅助V弯回弹规律,基于ABAQUS软件平台建立Ti55合金板材电辅助V弯电-热-力耦合三维有限元模型。对板材V弯及回弹过程进行正交试验模拟,研究弯曲角、相对弯曲半径、有效电流密度、成形速度对板材回弹的影响规律,建立了基于径向基函数的回弹预测模型。结果表明:在选取参数范围内,随着弯曲角、相对弯曲半径的增大和有效电流密度的减小,回弹角增大;随着成形速度的增大,回弹角先减小后增大。极差分析和方差分析得到弯曲角和相对弯曲半径对回弹角有显著影响。电辅助板材V弯相对机械V弯回弹角平均降低48.7%。进行电辅助V弯实验,对比厚度、温度和回弹角,平均误差分别为9.4%、4.6%和13.4%,验证了有限元模拟及回弹预测模型的准确性。 相似文献
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《塑性工程学报》2017,(2)
以宝钢生产的14种规格和牌号的钢板为研究对象,对其V弯成形特性进行了研究,通过单向拉伸实验,获得材料的基本力学性能,分析了试验材料的V弯回弹规律。试验结果表明,材料存在正、负回弹,相同弯曲角度下随弯曲半径增大,回弹量增加且趋向正回弹,在相同弯曲半径下,弯曲角度增大,回弹量减小且趋向负回弹,可通过调整弯曲角度或弯曲模具圆角大小来可合理控制零件回弹;在相同厚度条件下,当材料抗拉强度大于600 MPa时,回弹量显著增大;在相同强度条件下,回弹量随弯曲角度的增大而趋向负回弹,同时随着弯曲半径的变大,回弹量随材料厚度产生的差异趋缓,并趋向正回弹;980 MPa强度级别材料中材料厚度越小,不同弯曲半径下的回弹量差异变大;厚度相同的情况下,QP钢和MS钢的回弹量比DP钢更趋向于正回弹;数值拟合发现,回弹角度随R/T值的增大而增大,且经历一个由负到正的过程。随着弯曲角度的增大,拟合曲线下移且斜率变小,只有当R值足够大时才会出现正回弹。 相似文献
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工艺参数和材料性能对板料成形回弹的影响 总被引:1,自引:3,他引:1
分析总结了数值模拟中模拟参数(有限无算法、单元类型、材料模型、本构方程、积分点选取、接触和摩擦法则等)对回弹模拟精度的影响。对一细长支腿零件的工艺成形过程进行了数值模拟,研究了工艺参数及材料性能参数(压边力、凸模圆角半径、凸凹模间隙、板料厚度、摩擦系数、材料硬化指数)对工件回弹的影响。回弹角随凸模圆角半径和凸凹模间隙的增大而增大,随压边力、扳料厚度、摩擦系数和材料硬化指数的增大而减小。 相似文献
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对金属管材在弯曲条件下的应力-应变关系进行分析,基于弹性-幂强化材料模型,在中性层附近的弹性变形区采用线性关系描述应力-应变关系,在塑性变形区采用幂函数形式描述应力-应变关系。根据回弹理论,计算时考虑了管材壁厚,推导了金属管材弯曲回弹角的近似计算公式。计算结果表明,弹性变形区产生的回弹量占整体回弹量的比值非常小。回弹角的大小与材料的自身参数相关,随着弹性模量E、材料硬化系数n的增大而减小,随着塑性系数K、管材壁厚t的增大而增大。回弹角的大小与弯曲时的弯曲角度和曲率半径相关,随着弯曲角度α、曲率半径ρ的增大而增大。 相似文献
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This paper studies the springback after the lateral bending of T-section rails, considering the work-hardening materials. A linear-hardening model and an elastic-plastic power-exponent hardening model of the material are adopted and compared with the real experimental stress-strain curve obtained from the uniaxial tension tests. The analytical formulas for the springback and residual curvatures are given. The numerical results indicate that the material hardening directly affects the accuracy of springback prediction compared with the experimental results. Besides, springback prediction is not sensitive to hardening parameters in the beginning of elastic-plastic bending deformation. Although there is an apparent yield stage in the true stress-strain curve, the adopted hardening models can achieve an allowable relative error, if hardening parameters are properly selected. 相似文献
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为了评估DP980高强钢材料的成形与回弹特性,通过加载-卸载实验与单向拉伸-压缩循环加载实验,获得了考虑包申格效应的吉田-上森硬化模型参数,并对DP980高强钢的U形弯曲实验进行了研究。实验结果表明,DP980高强钢U形件在凹模圆角处易开裂,在成形过程中需减小压边力并增大凹模圆角。由于材料的回弹量与施加的压边力有关,可通过增大压边力来减小U形件的回弹,但压边力过大又可能导致开裂,因此,需合理选择压边力。同时,对U形件成形后的回弹进行仿真分析,仿真中分别采用等向硬化模型与吉田-上森硬化模型,通过将实验数据与模拟的回弹结果进行对比分析发现,采用吉田-上森硬化模型的仿真结果与实验结果吻合良好,证明了吉田-上森硬化模型模拟回弹的准确度较高,可以应用于回弹仿真中。 相似文献
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H. Li H. Yang F.F. Song M. Zhan G.J. Li 《Journal of Materials Processing Technology》2012,212(9):1973-1987
Stress-relieved Ti–3Al–2.5V bent tube in hydraulic bleeding systems improves the overall performance of advanced aircraft and spacecraft due to its unique high specific strength. However, the high ratio of yield strength to Young's modulus may induce significant elastic recovery after unloading. The precision bending of the high strength Ti-tube (HSTT) depends on the understanding of the springback features and mechanisms. Using the plasticity deformation theory, the explicit/implicit 3D-FE and the physical experiments, the springback behaviors of the HSTT under multi-die constrained cold rotary draw bending (RDB) are addressed. The results show that: 1) The elastic recovery of the HSTT should be characterized by the significant angular springback, the radius growth and the sectional springback; Both the angular and radius springback should be compensated, while the sectional one decreases the cross-section flattening; 2) Among multiple parameters, both the material properties (Young's modulus, strength coefficient and anisotropy exponent) and the geometrical dimensions (bending angle and bending radius) dominate the unloading; Both the angular and radius springback values decrease with the smaller bending radii; The angular springback increases linearly with the larger bending angles, while the radius growth fluctuates little with the increasing of the bending angles at the later bending stages; Both the springback values of the HSTT are far larger than the ones of the 5052O Al-alloy tube and the 1Cr18Ni9Ti tube; The maximum variations of the angular and radius springback with changing of the processing parameters are 78% and 62.5% less than the maximum ones under different material properties and geometrical ones, respectively. 3) A two level springback compensation methodology is proposed to achieve the precision bending in terms of both springback angle and radius. 相似文献
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基于PS2F的铝型材拉弯回弹研究 总被引:4,自引:0,他引:4
采用型材2D拉弯仿真软件PS2F对矩形截面铝型材张臂式拉弯进行了分析,探讨了弯曲半径、弯曲角度及铝合金材料性能对型材单曲率拉弯回弹的影响。研究结果表明,在缺省的拉伸力控制参数设置及夹钳加载轨迹由软件自动优化的情况下,对于给定的弯曲半径,型材零件端部的回弹量随弯曲角度的增加呈指数上升趋势;对于一定的弯曲角度,零件端部回弹量随弯曲半径的增加而线性增加;在相同弯曲半径和弯曲角度的情况下,材料性能对拉弯回弹量有重要的影响。 相似文献
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通过对V形弯曲回弹的讨论,建立一个V形弯曲回弹调节的试验模具模型.该模型的建立,旨在能够事先不需要计算就可以掌握该材料的回弹性能.该弯曲模具能够调节其弯曲角度的大小.试验时,先在能够进行弯曲回弹调节的模具上按照有关的回弹数据进行调节试验,确定材料的回弹值,而后进行模具设计.V形弯曲回弹调节的试验模具可以很准确地确定弯曲回弹的回弹量,为V形弯曲模具的设计带来极大的方便. 相似文献
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U形弯曲回弹正弦调节试验模具的建立与讨论 总被引:1,自引:0,他引:1
通过对U形弯曲回弹的讨论,建立一个U形弯曲回弹正弦调节的试验模具模型.该模型的建立,旨在不需要事先计算就能够掌握材料的回弹性能.试验时在能够进行弯曲回弹调节的模具上按照有关的回弹数据进行调节试验,确定材料的回弹值,然后再进行模具设计.这样可以大大减少模具设计后的试模和修模工作量,为模具设计者带来了极大的方便. 相似文献
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K. Yilamu R. Hino H. Hamasaki F. Yoshida 《Journal of Materials Processing Technology》2010,210(2):272-278
This paper deals with bending and springback phenomena of a stainless-steel clad aluminum sheet in V-shaped air bending. The aim of this study is to investigate the bending characteristics such as sheet thickness change and the bending angles of the sheet before/after springback. The first part of this paper is on the experimental observations. V-bending experiments were performed for both the cases of Alin/SSout (i.e., aluminum layer is located inside the bent clad) and SSin/Alout (i.e., stainless-steel layer is located inside the bent clad). From these results, it was found that the sheet-set condition (either Alin/SSout or SSin/Alout) has a great influence on the bending phenomena. In the second part, the accurate prediction of springback by FE analysis, especially the role of elasto-plasticity models, is discussed. When using Yoshida–Uemori kinematic hardening model (F. Yoshida, T. Uemori, Int. J. Plasticity 18, 2002; Int. J. Mech. Sci., 45, 2003), which well describes the Bauschinger effect of materials, the springback of the clad sheet is accurately calculated, whereas the classical isotropic hardening model underestimates the springback. 相似文献