环件轧制过程的显式有限元模拟分析

用于金属成形进行模拟的有限元方程的求解方法,主要有隐式和显式积分两种方法。对于复杂的三维变形分析,如环件轧制,隐式方法需要很长的运行时间。而利用显式方法,可以达到很好的效果。文中利用Abaqus/Explicit通用有限元程序对径向环轧进行了模拟。     

金属体积成形过程有限元模拟中六面体网格重划技术的研究

针对金属体积成形过程有限元模拟中的网格重划问题 ,提出了基于边界构形的有限元网格重划技术 ,并对其中的一系列技术处理进行了详尽的讨论。将该技术应用于矩形块体镦粗过程的有限元模拟中 ,较好地解决了六面体网格重划问题。     

基于温度循环失效机理的铝制金属密封圈疲劳寿命仿真

目的 解决真空法兰密封中的金属密封圈寿命难以预测的问题.方法 基于金属密封圈的失效机理,提出一种疲劳仿真方法 ,对金属密封圈的使用寿命进行有效预测.通过有限元仿真方法 对金属密封圈安装过程及其使用过程进行仿真模拟,得到金属密封圈使用过程的应力分布,然后结合Conffin-Manson疲劳模型,对金属密封圈的使用寿命进行...     

径轴向辗环机优化轧制规程的计算机辅助设计

此文介绍了利用数字计算机进行矩形截面环轧制的优化规程设计方法,优化是基于轧制过程的物理模型,考虑了各种轧制约束条件,结果符合实际生产情况,并且可使轧机容量得到充分利用,大大缩短轧制所需时间,节约材料与能源消耗。     

Warm forming die design,part I: Experimental validation of a novel thermal finite element modeling code

Finite element analysis (FEA) has become an invaluable tool in the design of sheet metal stamping dies and processes. FEA has gained widespread acceptance as the best method of optimizing dies for conventional stamping processes. More recently, FEA has been shown to be an effective method of designing tooling for sheet forming processes. In this work, an FEA based approach is applied to the warm stamping (warm forming) process. This work introduces a new thermal finite element analysis software called PASSAGE®/Forming (PASSAGE) that enables the up-front design of the thermal management of warm forming dies. This thermal finite element analysis software is designed to specifically handle the forming and optimization scenarios related to the heating of a stamping die while minimizing user interface time. In this work, PASSAGE has been applied to a simple block of steel embedded with cartridge heaters to validate the prediction capability of this software under two different heating conditions. The results show that PASSAGE is capable of predicting the actual steady-state temperature distribution within the block with an acceptable level of accuracy while yielding notable information to the user with respect to specifying power requirements. A finite element software package like PASSAGE is a valuable tool that will aid greatly in the implementation of warm forming as a manufacturing process beyond the scope of the laboratory and into production.     

Application of FEM simulation of chip formation to stability analysis in orthogonal cutting process

Models for chatter prediction in machining often use a mechanistic force model that calculate the force as the product of a material dependent cutting constant and chip area. However, in reality, the forces are the result of complex interaction between the tool and the chip, and are affected by many factors. The effects of these complex, and often nonlinear, factors on the machining dynamics may only be included in chatter prediction if the chip formation process is simulated concurrently with simulation of the machining dynamics. In this paper, finite element simulation of the chip formation process is combined with simulation of chatter dynamics and the inter-relationship between the chip formation process and the chatter phenomenon is investigated. Mesh adaptation technique is used to simulate the chip formation within an FEM elastoplastic analysis with dynamic effects and frictional contact. The combined modeling predicts the occurrence of process damping at low cutting speeds, which other models are generally unable to predict.     

超级钢闪光对焊电热耦合过程温度场分布的有限元分析

为研究超级钢闪光对焊闪光阶段焊件的温度场分布 ,建立了轴对称有限元模型。运用单元死活技术解决闪光时液体过梁爆破引起物质烧损的模拟问题 ,提出了闪光焊过程中电热耦合作用的模拟方法。考虑单元死活的有限元分析结果与试验结果更加吻合 ,为选择和优化闪光焊焊接参数以及为闪光焊过程顶锻阶段的热力耦合过程的模拟提供了有效的分析手段     

典型钢铁企业挥发性有机物排放量测算及组分特征

选取涵盖钢铁炼制全流程的典型企业,综合采用不同核算方法估算比较了该企业挥发性有机物（VOCs）排放结果;并在此基础之上,通过氟聚化合物气袋、SUMMA罐采样及气相色谱质谱联用仪（GC-FID/MS）分析方法,对烧结、焦化、热轧和冷轧等工序废气中VOCs浓度水平及排放特征进行监测.结果表明,整个厂区VOCs年排放量为430.82t,其中工艺有组织排放占66.0%,储罐18.5%;烧结机头和焦炉推焦排放口VOCs及非甲烷总烃（NMHC）浓度高于其他点位;各工序排放的芳香烃占比较高,其中焦化装煤除尘和焦炉推焦排放口芳香烃占90%以上;烧结工序CS₂占比最高（36.6%）,其次为苯和甲苯;焦化工序占比靠前的物种为1,2,4-三甲基苯、邻甲乙苯、1,4-二乙基苯、1,2,3-三甲基苯和1,3,5-三甲基苯等;热轧工序与其他工序有一定区别,车间无组织排放芳香烃和烷烃占比均在35%左右,排放靠前的物种除芳香烃外还有高碳烷烃,如十一烷、十二烷和正丁烷等;冷轧工序有组织和无组织排放主要物种较为类似,均为芳香烃物种,如乙基苯、间/对二甲苯、甲苯、苯和邻二甲苯.不同工艺环节排放物种存在一定差异,但主要以焦化副产物（芳香烃）和烧结燃烧产物（CS₂）为主,建议钢铁行业有针对性地加强浓度高、活性高和毒性大的组分控制.     

Modeling and simulation of arc: Laser and hybrid welding process

Welding is a fabrication process to join two different materials. Among the many welding processes, the arc and laser welding processes are the most widely used. Great effort is required to understand the physical phenomena of arc and laser welding due to the complex behaviors which include liquid phase, solid phase and, gas phase. So it is necessary to conduct numerical simulation to understand the detailed procedures of welding. This paper will present the various numerical simulation methods of the arc welding processes such as arc plasma, gas tungsten arc welding, gas metal arc welding, laser welding, and laser–arc hybrid welding. These simulations are conducted by the finite element method, finite differential method and volume of fluid method to describe and analyze the various welding processes.     

典型钢铁企业挥发性有机物排放量测算及组分特征

选取涵盖钢铁炼制全流程的典型企业,综合采用不同核算方法估算比较了该企业挥发性有机物（VOCs）排放结果;并在此基础之上,通过氟聚化合物气袋、SUMMA罐采样及气相色谱质谱联用仪（GC-FID/MS）分析方法,对烧结、焦化、热轧和冷轧等工序废气中VOCs浓度水平及排放特征进行监测.结果表明,整个厂区VOCs年排放量为430.82t,其中工艺有组织排放占66.0%,储罐18.5%;烧结机头和焦炉推焦排放口VOCs及非甲烷总烃（NMHC）浓度高于其他点位;各工序排放的芳香烃占比较高,其中焦化装煤除尘和焦炉推焦排放口芳香烃占90%以上;烧结工序CS₂占比最高（36.6%）,其次为苯和甲苯;焦化工序占比靠前的物种为1,2,4-三甲基苯、邻甲乙苯、1,4-二乙基苯、1,2,3-三甲基苯和1,3,5-三甲基苯等;热轧工序与其他工序有一定区别,车间无组织排放芳香烃和烷烃占比均在35%左右,排放靠前的物种除芳香烃外还有高碳烷烃,如十一烷、十二烷和正丁烷等;冷轧工序有组织和无组织排放主要物种较为类似,均为芳香烃物种,如乙基苯、间/对二甲苯、甲苯、苯和邻二甲苯.不同工艺环节排放物种存在一定差异,但主要以焦化副产物（芳香烃）和烧结燃烧产物（CS₂）为主,建议钢铁行业有针对性地加强浓度高、活性高和毒性大的组分控制.     

Shape calibration of high strength metal sheets by electromagnetic forming

Electromagnetic (EM) forming is an emerging technique that is gaining acceptance for its complementary benefits to conventional metal forming techniques. In this work an innovative application of this impulse forming technique has been demonstrated: the EM shape calibration and correction of springback (sidewall curl) of DP600 and TRIP700 high strength steel (HSS) workpieces. This method has been applied as a second corrective step to previously deep drawn U-channels. The experimental results confirm the sidewall curl angle correction, achieving them with a 22 kJ discharge for DP600 samples and 24 kJ for TRIP700.On the other hand, an uncoupled multiphysical simulation strategy has been carried out in order to virtually validate the EM shape calibration method. The EM fields were simulated by Maxwell 3D and then the Pamstamp code was used to obtain the deformation process.     

Numerical simulation of residual stresses for friction stir welds in copper canisters

In an attempt to map the residual stress distributions after friction stir welding of copper canisters, a three-dimensional thermo-mechanical model has been formulated by coupling heat transfer and elasto-plasticity analyses. The transient temperature field around the tool is simulated by a moving heat source. The simulation shows that the residual stress distribution in a thick-wall copper canister is sensitive to the circumferential angle and asymmetrical to the weld line. Both tensile and compressive stresses emerge along the weld line and its vicinity. The maximum tensile stress appears in the circumferential direction on the outer surface. The maximum tensile stress, whether it is predicted by the finite element method or measured by the hole-drilling technique and the X-ray diffraction method, does not exceed 50 MPa in general.     

Optimal and Robust Design of the Laser Forming Process

The laser forming process of sheet metal has been extensively analyzed, but few attempts have been made in the area of process design. The task of the process design in the laser forming of sheet metal is to determine a set of parameters, including laser scanning paths, laser power, and scanning speed, given a prescribed shape. Response surface methodology is used as an optimization tool. The propagation of error technique is built into the design process as an additional response to be optimized via desirability function and hence make the design robust. Focusing on a class of shapes, the design scheme is applied progressively in four cases in which issues such as a large number of design variables are properly addressed.     

钢窗手柄冷楔横轧工艺

分析了楔横轧成形条件,以冷楔横轧钢窗手柄为例探讨了工艺方案选择和工艺参数确定.试轧获得基本成功.如用于实际生产尚须进一步提高加工精度.     

用于环境适应性分析的航电产品应力仿真技术

热和振动是引起航空电子产品环境适应性问题的2个主要应力,因而在设计过程中应当开展产品的热和振动应力分析.介绍了用于环境适应性分析的航空电子产品数字样机及其建模方法;讨论了基于计算流体力学(CFD)技术的航空电子产品热应力仿真分析方法,以及基于有限元(FEM)技术的振动应力仿真分析方法,并给出了分析案例.     

收口工艺反向模拟技术研究

综述了国内外反向模拟技术 ,介绍了收口工艺特点 ,建立了收口反向模拟技术的理论和系统流程 ,并针对收口工艺提出了反向模拟边界条件确定方法。     

导布辊辊筒加工用辘头、辘模和辘床

分析了导布辊辊筒加工中的一个重要工艺辘圆工艺。论述了完成这个工艺的装备 ,辘头、辘模和辘床的一些设计方法     

方轧件在椭圆孔型中轧制温度场的三维有限元分析

应用MARC/autoforge有限元软件对方轧件在椭圆孔型中的轧制温度场进行了热力耦合模拟.研究了模拟过程中的传热边界条件,分析了轧制前和轧制过程中轧件中温度场的分布和变化规律.模拟计算结果和实验结果的比较说明二者基本是相符的.     

可移式模具在楔横轧工艺中的应用

通过使用可移式轧辊模具 ,成功地利用一副模具轧制出了形状相似、仅局部尺寸不同的多种规格的阶梯轴 ,使楔横轧工艺在规格较多、批量较小的轴类零件毛坯成形中得到了应用 ,楔横轧技术得到了进一步发展和推广。     

板料冲压过程的数值仿真与参数优化

采用有限元动态分析技术,采用HILL屈服准则,模拟了板料拉深成形的过程,结合实验拉深进行比较,模拟结果与实验数据符合。应用0.618一维搜索优化方法,在数值模拟中对压边力进行了优化,为实验中压边力的确定提供了参考数据。