共查询到20条相似文献,搜索用时 93 毫秒
1.
介绍了一种基于脉冲等离子焊接快速成形的方法,并采用Taguchi法对单道成形试验进行了合理设计,从而获得了多组焊接工艺参数下的熔宽和余高数据.通过遗传算法(GA)结合BP神经网络的方法建立了等离子焊接快速成形的预测模型,该模型预测了不同焊接成形工艺参数下单道成形的熔宽和余高.结果表明,通过误差分析和线性回归的方法验证了模型具有较高的预测精度和泛化能力,能够合理的预测焊道尺寸,并能推广到多层多道堆积成形尺寸的预测. 相似文献
2.
V. Malikov R. Ossenbrink B. Viehweger V. Michailov 《Journal of Materials Processing Technology》2013,213(11):1811-1817
The structured sheet metals with hexagonal based contour and free formed bump geometry have several advantages compared to smooth sheet metal. The most important benefit is the improved stiffness. During processing of the structured sheet metals the stiffness properties are changing due to transformation of the initial geometry. In this study the change of the stiffness of the structured sheet metal during the deep drawing is investigated. Two cases are considered: deep drawing and compression. The results show a significant change of the geometry and mechanical properties of the structured sheet metal in both cases. The relationships between the flattening and stiffness properties in both cases were discussed in detail. Moreover the presented results allow the determination of the process limits for the deep drawing of the structured sheet metal to secure their improved stiffness. 相似文献
3.
Selection of process parameters has great influence on the quality of a welded connection. Mathematical modelling can be utilized in the optimization and control procedure of parameters. Rather than the well-known effects of main process parameters, this study focuses on the sensitivity analysis of parameters and fine tuning requirements of the parameters for optimum weld bead geometry. Changeable process parameters such as welding current, welding voltage and welding speed are used as design variables. The objective function is formed using width, height and penetration of the weld bead. Experimental part of the study is based on three level factorial design of three process parameters. In order to investigate the effects of input (process) parameters on output parameters, which determine the weld bead geometry, a mathematical model is constructed by using multiple curvilinear regression analysis. After carrying out a sensitivity analysis using developed empirical equations, relative effects of input parameters on output parameters are obtained. Effects of all three design parameters on the bead width and bead height show that even small changes in these parameters play an important role in the quality of welding operation. The results also reveal that the penetration is almost non-sensitive to the variations in voltage and speed. 相似文献
4.
Sensitivity analysis for process parameters in GMA welding processes using a factorial design method 总被引:1,自引:0,他引:1
I. S. Kim K. J. Son Y. S. Yang P. K. D. V. Yaragada 《International Journal of Machine Tools and Manufacture》2003,43(8):206
Generally, the quality of a weld joint is strongly influenced by process parameters during the welding process. In order to achieve high quality welds, mathematical models that can predict the bead geometry and shape to accomplish the desired mechanical properties of the weldment should be developed. This paper focuses on the development of mathematical models for the selection of process parameters and the prediction of bead geometry (bead width, bead height and penetration) in robotic GMA (Gas Metal Arc) welding. Factorial design can be employed as a guide for optimization of process parameters. Three factors were incorporated into the factorial model: arc current, welding voltage and welding speed. A sensitivity analysis has been conducted and compared the relative impact of three process parameters on bead geometry in order to verify the measurement errors on the values of the uncertainty in estimated parameters. The results obtained show that developed mathematical models can be applied to estimate the effectiveness of process parameters for a given bead geometry, and a change of process parameters affects the bead width and bead height more strongly than penetration relatively. 相似文献
5.
《Journal of Materials Processing Technology》2014,214(8):1673-1685
In this paper, an enhanced numerical method for forming tool design optimisation in three-dimensional (3D) sheet metal forming applications is presented. The applied procedure enables a determination of appropriate forming tool geometry so that the manufacture of a sheet metal product inside specified tolerances would be ensured. In addition to the springback that occurs in the formed part after removal of the forming tools, the impact of the thinning of the sheet metal during the forming process is considered in the method, and both effects are correspondingly compensated for an iterative procedure. Computational efficiency in the E-DA-3D method is achieved mainly because the improved accuracy of the communicated data established corresponding interrelations between the discretised topologies used in the definition of the prescribed product geometry, the current tool geometry, and on this basis actually computed product geometry which is achieved by means of additional point topology mappings. The potential and effectiveness of the method is demonstrated by considering two cases of the forming tool design optimisation that are also experimentally validated. 相似文献
6.
Surface reconstruction for incremental forming 总被引:1,自引:0,他引:1
A. Erman Tekkaya Ravi Shankar Gerd Sebastiani Werner Homberg Matthias Kleiner 《Production Engineering》2007,1(1):71-78
In spite of extensive efforts being made with regard to virtual process optimization technology, the production of prototype
parts is still a necessity. With respect to the production of sheet metal parts in low quantities, incremental sheet metal
forming (ISMF) is a highly interesting process. ISMF allows the production of complex parts with drastically reduced costs
in tooling and machinery compared to conventional processes like deep drawing. However, ISMF, with it’s incremental nature,
introduces the need for generating a tool path considering both final geometry and process-induced deviations or constraints.
Consequently, for the generation of the tool path a (tool path) surface, with an adequate offset, is necessary. That is why,
within the scope of extensive research work at the Institute of Forming Technology and Lightweight Construction (IUL), a special
correction module has been developed, determining this offset e.g. depending on the workpiece geometry. This paper presents
the algorithm, the application, and the effect on the produced parts. Furthermore, a concept for an extension regarding further
constraints like elastic workpiece behavior is presented. 相似文献
7.
阶梯盒形件是汽车制造业中的典型零件,但是由于其拉伸成形困难,废品率较高.针对某阶梯盒形件进行了工艺性分析,规划了冲压生产工艺,并利用AutoForm软件对拉伸成形过程进行了仿真模拟,选取板料尺寸、摩擦系数及压边力为研究对象,对比分析了3个参数对拉伸质量的影响规律,最后给出了优化成形质量的建议,对指导实际生产有一定的意义... 相似文献
8.
Experiments on drawbead restraining in sheet metal forming with several bead configurations were carried out. With the binder hold-down force as an independent variable, the magnitude of the restraining force, the amount of metal flow through the bead, and the sensitivity of these quantities with respect to lubrication were determined. Performance of these beads as viewed from shop floor practices was discussed. 相似文献
9.
10.
Dae Young Lee Leifur Leifsson Jin-Young Kim 《Science & Technology of Welding & Joining》2020,25(3):208-217
In this paper, an additional filler wire with opposite polarity was inserted in tandem flux cored arc welding process to increase the welding speed and deposition rate. In this hybrid welding, the optimisation of welding parameters is required to improve the bead geometry which directly indicates the welding quality. However, the correlation between the parameters and the bead geometry is hard to identify, so the process parameters are usually selected intuitively by the experienced engineers. Therefore, welding process modelling is constructed with the Gaussian process regression model, and parameter optimisation is performed with sequential quadratic programming optimisation algorithm. The proposed modelling optimisation process is verified by performing the welding experiment using the parameters that are optimised by the proposed process. 相似文献
11.
12.
《Science & Technology of Welding & Joining》2013,18(5):347-352
AbstractWith the advanced developments and automation of the welding process, the use of process optimisation techniques has increased. The objective of the present paper is to describe process optimisation techniques for the gas metal arc (GMA) welding process, based on experimental results generated by the process. Back propagation (BP) neural network and multiple regression methods are employed to study relationships between process parameters and top bead height for robotic multipass welding process, and to select a suitable model that provides the weld final configuration and properties as output and employs the process parameters as input. The process parameters, namely pass number, arc current, welding voltage and welding speed are optimised to produce the required top bead height. These techniques have achieved good agreement with the experimental data and yielded satisfactory results. Also, the BP neural network that was developed was compared to the empirical equations for predicting top bead height through additional experiments, and it was evident that the BP neural network was considerably more accurate than multiple regression techniques. 相似文献
13.
Laser transformation hardening (LTH) of unalloyed titanium of 1.6 mm-thick sheet, nearer to ASTM Grade 3 of chemical composition was investigated using 2 kW CW Nd:YAG laser. The effects of laser power (750-1 250 W), scanning speed (1 000- 3 000 mm/min) and focal point position (from -10 to -30 mm) on the heat input, and hardened-bead geometry (i.e. hardened bead width (HBW), hardened depth (HD) and angle of entry of hardened bead profile with the surface (AEHB)) were investigated using response surface methodology (RSM). The experimental plan is based on Box-Behnken design matrix method. Linear and quadratic polynomial equations for predicting the heat input and the hardened bead geometry were developed. The results indicate that the proposed models predict the responses adequately within the limits of hardening parameters being used. It is suggested that regression equations can be used to find optimum hardening conditions for desired criteria. 相似文献
14.
Elsyca Plating Master, a new SolidWorks based simulation tool to compute current density and deposit thickness distributions for electroplating processes, is presented. Complex three-dimensional shaped workpieces in arbitrarily designed plating cells can be modelled. The software enables optimising the cell design (e.g. anode, screen and current thief configuration) and working conditions (e.g. total current, pulse parameters) for a large variety of plating processes. Additionally, it provides the Production Department the analytical data to discuss the manufacturability of a product design with Design und Engineering. The application of Elsyca PlatingMaster for the prediction and optimisation of a chromium deposition process for complex three-dimensional parts is illustrated. 相似文献
15.
实用钣金展开CAD系统的开发技术与应用研究 总被引:8,自引:1,他引:8
在分析钣金展开计算和绘图方法的基础上,详细地讨论了实用钣金展开CAD的系统结构和开发方法。最后结合钣金展开应用实例。系统地说明利用几何数学计算法结合计算机辅助设计和AutoCAD系统的绘图环境,如何进行钣金件展开计算,自动生成钣金展开图和相应的展开计算数据文件。目前,该方法已经成功地用于开发钣金展开CAD系统。 相似文献
16.
在金属板材的电磁脉冲拉深成形中,采用一种使成形件凸缘部分的材料可以径向流动的方法。形成了一种拉深—胀形特点相结合的成形工艺,可以提高材料的拉深极限。在此基础上通过改变电压和板料直径等工艺参数,可获得更大拉深高度。 相似文献
17.
Jae C Choi Byung M Kim Hae Y Cho Chul Kim 《International Journal of Machine Tools and Manufacture》1998,38(8):931-963
This paper describes the development of a computer-aided design of blanking and piercing for irregular-shaped sheet metal products and stator and rotor parts. An approach to the compact and practical CAD system is based on the knowledge-based rules. Knowledge for the CAD system is formulated from plasticity theories, experimental results and the empirical knowledge of field experts. The system has been written in AutoLISP on the AutoCAD with a personal computer and is composed of six main modules, which are input and shape treatment, production feasibility check, blank layout, strip layout, die layout, and drawing edit module. Based on knowledge-based rules, the system, STRTDES, is designed by considering several factors, such as complexities of blank geometry and punch profile, availability of press equipment and standard parts, utilization ratio which minimizes the scrap in a single or a pairwise operation, bridge width, grain orientation and design requirements which maximize the strength of the part when subsequent bending is involved. Therefore, this system can carry out a die design for each process which is obtained from the results of an automated blank layout drawing with the best utilization ratio for the irregular shape of the product, which was successful in the production feasibility check module, and those of an automated strip layout drawing. It can then generate part drawings and the assembly drawing of the die set in graphic form. The developed system provides its efficiency and effectiveness for blank layout, strip layout, and die layout of irregular-shaped sheet metal products and stator and rotor parts. 相似文献
18.
Ahmed Hussein Liang Hao Chunze Yan Richard Everson Philippe Young 《Journal of Materials Processing Technology》2013,213(7):1019-1026
Metal additive manufacturing (MAM) of complex parts with overhangs typically requires the use of sacrificial support structures to hold the part during the process. This structures which are built simultaneously with the part, anchors the overhang geometry to the base plate and prevent distortion/curling resulting from thermal stresses. They are necessary, but add constraints to the geometries that the processes can make. The design and selection of support structure can influence the manufacturability of complex metal parts, material and energy utilization, manufacturing time and cost. This study takes a new step on the design and manufacturing a more efficient support through the novel application of lattice structures with very low volume fraction. Experiments were conducted in direct metal laser sintering (DMLS) machine using titanium alloy Ti6Al4V powder. Experimental results revealed that the type of structure, volume fraction and cell size are the main factors influencing the manufacturability, amount of support, and built time of lattice support structures. Lattice supports with very low volume fraction up to 8% were built, saving significant amount of materials used in the support while reducing built time of making MAM parts. 相似文献
19.
In the manufacture of high-quality welds or pipeline, a full-penetration weld has to be made along the weld joint. Therefore,
root-pass welding is very important, and its conditions have to be selected carefully. In this study, an experimental method
for the selection of optimal welding conditions is proposed for gas tungsten arc (GTA) pulse welding in the root pass which
is done along the V-grooved butt-weld joint. This method uses response surface analysis in which the width and height of back
bead are chosen as quality variables of the weld. The overall desirability function, which is the combined desirability function
for the two quality variables, is used as the objective function to obtain the optimal welding conditions. In our experiments,
the target values of back bead width and height are 4 mm and zero, respectively, for a V-grooved butt-weld joint of a 7-mm-thick
steel plate. The optimal welding conditions could determine the back bead profile (bead width and height) as 4.012 mm and
0.02 mm. From a series of welding tests, it was revealed that a uniform and full-penetration weld bead can be obtained by
adopting the optimal welding conditions determined according to the proposed method. 相似文献