共查询到20条相似文献,搜索用时 291 毫秒
1.
采用非线性有限元软件对铜管游动芯头拉拔工艺中不同配合锥角的模具受力情况和铜管表面的受力情况进行了数值模拟和分析,推断企业目前使用的模具锥角配合是否合理,以分析当前模具锥角配合是否为影响模具寿命的主要原因。 相似文献
2.
借助ANSYS软件显式动力模块建立了游动芯棒拔制三维有限元模型,动态模拟了游动芯棒拔制的整个过程,根据得到的应力分布规律分析了生产中产生横裂问题的机理。并将拔制力分为四个阶段:起始、初步接触、完全接触、稳定。由于合理配模锥角是游动芯棒是否能稳定在变形区的最显著因素,就此对配模锥角进行了优化,所得结果可为游动芯棒配模锥角选择提供可靠的依据。 相似文献
3.
Tanit Tangsri Somchai Norasethasopon Kazunari Yoshida 《The International Journal of Advanced Manufacturing Technology》2014,70(9-12):1923-1930
This paper is concerned with the development of ultra-small inner spiral ribbed copper tubes with high-quality heat transfer. Since the demand for the ultra-small tubes in electrical appliances is currently high and will be greater in the future, the technology employed must enable the production of inner spiral ribbed fine tubes with various features, such as small size, high quality, high functionality, and low processing cost so as to meet the increasing demand. The conventional production method is suitable for large tubes with high drawability but is unsuitable for fabrication of long ultra-small tubes because of the difficulty to manufacture both an ultra-small spiral ribbed mandrel and a floating plug. This research paper has proposed four drawing methods as follows: tube sinking, water, oil, and wax as mandrels and presented the comparison of seven parameters, i.e., drawing stress ratio, wall thickness ratio, ribbed base width ratio, ribbed tip width ratio, ribbed height ratio, ribbed pitch ratio, and ribbed spiral angle ratio. It was found that tube sinking was unfit for making the ultra-small inner spiral ribbed copper tubes due to the resulting high ratio of wall thickness. The results of all the parameters were similar in the cases of oil and wax. Despite less impressive outcomes, water was easily removed from the inner spiral ribbed copper tube compared to oil and wax. Thus, the tube drawing using water as mandrel was most suitable for the production of the inner spiral ribbed copper tube. 相似文献
4.
铜合金管材铸轧工艺设计专家系统的开发及应用 总被引:7,自引:1,他引:7
针对铸轧工艺设计工作量大、效率低的问题,进行了“铜合金管材铸轧工艺专家系统”软件的开发。该系统将知识推理、神经网络、遗传算法、数值模拟、均匀设计和CAD参数化设计等技术运用到工艺设计和参数优化中,充分发挥各自技术优点,克服了传统专家系统智能程度低、设计方法单一和知识获取困难的缺点。利用该系统,可实现铸轧工艺中水平连铸、三辊行星轧制和游动芯头拉拔三个主要工序的智能化工艺设计,解决了铜管材加工过程中的各种实际问题。 相似文献
5.
Wujiao Xu Kaiqing Wang Pengcheng Wang Jie Zhou 《The International Journal of Advanced Manufacturing Technology》2011,57(1-4):1-9
Aluminum rectangular tube is the key component in the field of microwave transmission whose service condition requests strict dimensional accuracy and internal surface quality. To meet these requirements, a newly developed plug featuring a tiny boss club structure in the sizing zone has been proposed in the plug drawing process. The optimal combination of the dimensions in the boss club has been obtained using the method of 3D finite element simulation and orthogonal experimental design. The plastic strain distribution, the contact status between the tube inner surface and the plug, the dimensional accuracy of the formed part, and the forming load have been compared between conditions where the traditional linear-type plug and this new type of plug have been used, respectively. It can be seen clearly that when the plug with a tiny boss club structure is adopted, the contact quality is better and the larger plastic strain exists on the inner surface of the tube, which is very crucial in improving the surface finish of the formed part. Meanwhile, the deviation of wall thickness and the axial length in the formed part is smaller based on the new type of plug. The experiment of the drawing process with two types of plugs has been carried out in which the surface finish of the inner tube surface and the wall thickness have been measured and compared. Experiment result shows that the dimensional accuracy and inner surface quality meet the requirements of the service condition when the plug with a tiny boss club structure is employed. 相似文献
6.
无缝钢管穿孔生产是利用穿孔机将实心管坯斜轧穿孔成空心毛管的生产过程。斜轧穿孔中毛管质量与许多工艺参数,如辊型、送进角、顶头前伸量及温度,以及设备性能参数如穿孔机刚度、加工精度和顶杆振动等有关。由于其具有复杂的金属流动状态,传统的轧制理论难以解决其质量预报问题。本文通过对斜轧穿孔过程的分析,提出了步进子时段MICR(multiway independent component regression)算法,利用现场采集的多根毛管生产数据建立了预测毛管质量的数学模型。经仿真证明该模型具有较高的可靠性和精度,可以用于毛管质量的在线预报和优化。 相似文献
7.
介绍了玻璃管生产线中的玻璃管数控切割系统的结构及工作原理。数控系统的设计从控制刀盘旋转周期与拉管速度间的关系入手,实现保证玻璃管长度的目的。解决了玻璃管生产过程中,其切割过程无法适应拉管速度变化而引起玻璃管长度误差较大的问题。 相似文献
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Seong-Chan Heo Young-Ho Seo Tae-Wan Ku Beom-Soo Kang 《Journal of Mechanical Science and Technology》2011,25(2):429-439
Exhaust gas recirculation (EGR) cooler consists of a number of heat transfer tubes that have relatively larger net area than
that of flat type tubes. The surface of the tubes is made up with lots of grooves and protrusions for enlarging the net heat
transfer area. Most tubes are manufactured through forming processes, such as bending, spinning, roll forming, stamping and
so on. Therefore, a series of fracture or defect can occur during the various forming processes. In this study, the manufacturing
process of a dimple-type rectangular heat transfer tube used for an EGR cooler system is investigated based on the numerical
simulation and the experimental approach. A prototype of the tube is designed and modified to a newly designed tube considering
the conservation of the net heat transfer area based on the numerical and analytical approach. Formability evaluation of the
tube sheet is carried out by using forming limit curves based on the plastic instability conditions. Strain- and stress-based
forming limit curves are utilized to ensure the strain path independence. The newly designed tube having a number of dimples
on the both sides are manufactured by the press forming process. Thickness distributions for the principal cross-sections
are observed from both the simulation and the experiment and compared each other. From the results, it is confirmed that the
forming process is robust to manufacture the dimple type rectangular tubes with the comparison of thickness, and application
of the forming limit curves. 相似文献
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Effects of hydrostatic pressure and material anisotropy on the transient creep of thick-walled tubes
Effects of hydrostatic pressure and material anisotropy on the transient creep of pressurized thick-walled tubes are discussed. Constitutive equations which include these factors are formulated first of all so that the creep of a thick-walled tube of 0.19% carbon steel at 450°C is analysed by means of them. Strain-hardening and time-hardening hypotheses are employed. The results of the analyses are compared with those of the von Mises and Tresca-type theories together with corresponding experimental results hitherto reported. Material anisotropy of 10 per cent as between creep rates in the axial and circumferential direction is found insufficient to account for the deviations of the analytical results due to the von Mises or Tresca-type theory from the experimental ones. The effect of hydrostatic pressure is also found not to have a significant influence on the present problem. The validity of the assumption of vanishing axial strain which has been employed in preceding papers is also examined. 相似文献
13.
工艺参数对三维非轴对称管件缩径旋压成形的影响 总被引:1,自引:0,他引:1
以6061T1(挤压态及退火态)铝合金为研究对象,探讨工艺参数对三维非轴对称管件缩径旋压成形的影响。结果表明,当材料状态及其他工艺参数相同时,与轴对称零件相比,偏心及倾斜类零件的极限名义缩径量要小得多;轴对称件所能采取的进给比下限最低,而倾斜件的进给比下限最高;当旋转圆角半径过小时,会使工件表面粗糙度值变大,甚至出现破裂现象;旋轮直径对极限名义缩径量的影响不大。当工艺参数选择不合理时,工件口部或起旋点附近易产生破裂现象,为危险截面所在位置。 相似文献
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Young Choi Dae Up Kim Bong Yong Kang Dong Ku Park Dong Jin Lee Si Woo Lee Hee Tack Shin 《Journal of Mechanical Science and Technology》2013,27(11):3445-3449
In today’s reality, which requires automotive technical development to be environmentally friendly and highly efficient, lightening the weight of the propeller shaft for automobile actuation is also required. Some automobile manufacturers have developed and are applying the propeller shaft for automobile actuators to their production and accomplishing more than 30% reduction in weight by replacing steel materials with high strength aluminum alloy. For the propeller shaft, manufacturing technology of aluminum tube with high stiffness and high precision is required due to the problems of noise and vibration. In this study, the seamless tubes of aluminum alloy 7003 are hot extruded and cold drawn. The forming processes are simulated and modified to reduce and make uniform any plastic deformation. More precious tubes can be obtained by modifications. Extrusion with hollow billet and optimization of drawing tools were introduced for the production of an aluminum tube with high strength and high precision for the propeller shaft. 相似文献
16.
Abolfazl Darvizeh Mansour Darvizeh Reza Ansari Ata Meshkinzar 《Journal of Mechanical Science and Technology》2014,28(10):4199-4212
In this paper, the energy absorption characteristics of grooved circular tubes are investigated under quasi-static loading condition. For experiments, thick-walled tubes with circumferential grooves are prepared. The grooves divide the thick-walled tube into several shorter thin-walled portions. Specimens are subjected to axial crushing load to observe the effect of distribution of circular grooves on the deformation mechanism and energy absorption capacity. Geometrical parameters of the specimens are designed utilizing the Taguchi method to cover a reasonably wide range of groove length-to-wall thickness ratios. An analytical approach based on the concept of energy dissipation through the plastic hinges is applied. Taking the effect of strain hardening into account, the obtained analytical results are in good agreement with the experimental ones. The agreement between analytical and experimental results may indicate the validity of the proposed analytical approach. Desirable mechanism of deformation observed justifies the pre-forming method for obtaining favorable energy absorption characteristics. 相似文献
17.
A. R. Ragab 《International Journal of Mechanical Sciences》2002,44(3):601-620
A phenomenological formulation based on a theory of plasticity for voided solids, and power-law creep, to estimate the rupture times and strains for pressurized tubes is presented. Realistic values of the damage parameters involved are selected by satisfying the creep rupture uniaxial data for the same materials. Void growth and coalescence and hence the loss of load-carrying capacity of the tube is taken as a failure criterion. Computed values of rupture times for thin- and thick-walled tubes are shown to be mostly in close agreement with the experimental data found in the literature. Only fair agreement among predicted and experimental fracture strains is observed. 相似文献
18.
The paper investigates the influence of reverse yielding on residual stresses induced by autofrettage. On the basis of reverse loading tests, a material model is developed and implemented into analytical procedures capable of treating the elasto-plastic deformation behaviour of thick-walled tubes during both loading and unloading phases. The results show that residual hoop stresses are drastically reduced near the tube bore as compared with residual stresses obtained from conventional isotropic hardening analysis. Pure kinematic hardening analysis is also shown to overestimate residual hoop stress induced by autofrettage. 相似文献
19.
针对汽车前部纵梁结构的耐撞性要求,设计了在矩形空心管内部填充成组圆管的组合梁结构,研究了组合直梁在轴向冲击载荷下的能量吸收与变形特性,并进一步研究了填充圆管直径和长度等参数变化对组合梁的性能影响。结果发现,矩形薄壁梁内部填充圆管以后,结构的碰撞吸能特性得到较大程度的提高;通过合理的改变填充圆管的数量和长度,可以较好地调整结构压溃过程中的碰撞力峰值载荷和均值载荷。 相似文献