共查询到19条相似文献,搜索用时 62 毫秒
1.
2.
对薄壁Y型三通管的内管压成形进行研究。通过轴向补料,管材可以被推入模腔从而获得更高并且相对减薄率小的支管。但是Y型三通管的导向区较长,在内压作用下管材和模具之间会产生较大的摩擦力,使得材料难以流入支管。提出了采用多段式冲头用来改变导向区的内压分布并且减小导向区的摩擦力的方法。对铝合金Y型三通管进行内高压成形实验,采取两种方案,分别使用传统冲头和多段式冲头进行对比。对壁厚分布和减薄率分布进行研究,并对使用不同冲头的结果进行对比。 相似文献
3.
4.
5.
6.
7.
对子弹铅套成形过程中的破裂缺陷进行预测。采用单向拉伸实验获得纯铅真实应力-应变数据,选取应变0.006≤ε≤0.2范围内的数据进行拟合和外延处理获得材料无损伤的本构模型。结合扫描电镜分析法和基于响应面的有限元反求法获得纯铅的GTN细观损伤模型参数,对比分析单向拉伸中模拟与实验获得的载荷-位移曲线和铅材料孔洞体积分数,验证了所建立的纯铅GTN细观损伤模型的准确性。基于ABAQUS模拟仿真平台,耦合所建立的GTN损伤模型对铅套成形过程中的破裂行为进行仿真预测,并开展了铅套反挤压和变薄拉深成形实验。结果表明:实验结果与基于GTN损伤模型的仿真结果匹配良好;对铅套成形缺陷的准确预测是铅套成形优化的重要基础。 相似文献
8.
9.
10.
板材成对液压成形可以用于制造复杂几何截面的空腔构件,通过合理的工艺加载路径可以实现板材的流动控制。研究非焊接板材成对液压成形工艺以及两个主要工艺参数(合模力和液压力)的影响。通过理论计算研究不同合模力对应的极限液压力,得到极限液压力曲线,揭示不同工艺参数组合对变形行为的影响规律。通过有限元分析和实验研究验证了理论值,结果表明它们之间具有较好的一致性。实验采用2种线性加载路径和1种阶梯型加载路径研究加载路径对变形行为和零件成形性的影响,结果表明采用阶梯型加载路径可以得到很好的成形性。 相似文献
11.
12.
采用实验和固体元数值模拟研究了铝合金矩形截面内高压成形过程塑性变形的发生与发展规律,给出了主应力三维图形可视化表征及在屈服柱面上的应力轨迹,分析了典型点应力及应变状态。结果表明:在矩形截面内高压成形过程中,圆角区外层首先发生屈服,圆角区内层两端部分各约1/4区域最后进入塑性变形。圆角区应变状态为沿着厚向缩短和环向伸长的趋势变化,过渡点最先发生塑性变形并且等效应变始终最大。在变形过程中随着内压的增大,过渡点的轴向应力始终为拉应力。 相似文献
13.
14.
15.
Discrete layer forming proposed in this study is a hydroforming process which can selectively deform the outer tube to a desired shape without any deformation of the inner tube by piercing small holes in the inner tube. A three-layered tube is assembled from inner, middle, and outer tubes, from either similar or dissimilar materials, and deforms simultaneously when internal pressure and axial feed are applied to the tube. In special working environments, multi-layered tubes with combined material properties, high strength, and corrosion resistance are required to satisfy conflicting performance requirements. The feasibility of proposed discrete layer forming process of three-layered tube was evaluated by a tube hydroforming experiment and process analysis was performed. An optimal loading path to prevent wrinkling around holes was developed by an analytical model and was experimentally verified. The results show that the proposed discrete layer forming process can be successfully applicable to hollow forming of non-axisymmetric multilayered tubes for structural purposes. 相似文献
16.
Determination of material properties for hot hydroforming 总被引:1,自引:0,他引:1
For the process design of hydroforming in the “hot” temperature range, reliable data are necessary to describe the material
behaviour at elevated temperatures under the occurring loads of hot hydroforming processes. State-of-the-art technologies
for the investigation of material behaviour, like uniaxial tensile tests or hydraulic bulge tests, do not provide enough similarity
with the process of hot hydroforming. This paper describes a new testing technique, capable of realizing high process temperatures
and constant strain rates. It represents a further development of the established technology of tube bulge tests. The hardware
is described, its functionality is proven and mathematical approaches for the calculation of stress/strain-curves from experimental
data are presented. 相似文献
17.
18.
Optimization of loading conditions for tube hydroforming 总被引:12,自引:0,他引:12
Tube hydroforming is a developing technology with advanced features of lightness and unified part. This study investigates the best possible regulation for loading conditions between the internal pressure and the axial feeding by hydroforming of a T-shape metal tube. Using conjugate gradient method with finite element method, a program module is generated to check the hydroformed tube quality about its thickness uniformity and the geometry accuracy. Thereby, a batch mode and a sequential mode to optimize the loading conditions of the tube hydroforming process are created and investigated. Regarding the tube quality from the simulation results, the hydroforming process, which follows the loading curve generated by the sequential mode, is better than by the batch mode. The optimal loading procedure generated by this article can offer another possibility for engineer by determining the internal pressure and the axial feeding in tube hydroforming. 相似文献