基于数值模拟的钣金件级进冲压成形探析

利用数值模拟技术对级进成形工序进行分析和优化是非常重要的。本文以飞机机身某钣金零件为例,分析确定零件的成形工艺方案及参数。综合运用UG、Autoform软件建立了该零件级进冲压全工序数值模拟排样料带模型,采用多工位单工序有限元建模及模拟方法,对整个料带不同工位的成形过程进行了数值模拟,重点分析了压型和折弯两个工位,准确预测了各工位成形过程中可能出现的缺陷,验证了成形工艺方案的合理性。     

基于DEFORM-3D的超越离合器内星轮温挤压工艺研究

对装载机用滚柱式超越离合器内星轮进行温挤压成形数值模拟,研究了凹模入模角及坯料直径对内星轮成形性能的影响,结果表明当入模角为150°,毛坯直径为125mm时,内星轮的成形性能最好,经实践验证,生产出的样品尺寸精度良好,该新工艺具有优质高效、节约材料与能量的特点,适用于内星轮的精密成形。     

深锥筒形件挤压工艺的数值模拟优化

用MSC Superform软件对温挤压成形工艺进行模拟,分析并优化不同挤压模型的金属流动情况及应变大小,对比不同工艺条件下的挤压力大小. 模拟结果表明,综合考虑金属流动情况和模具强度及使用寿命,选用一步挤压并且成孔较好,对实际生产指导意义较强.     

基于ANSYS-LSDYNA有限元模拟的铝合金管件弯曲成形

为解决5754铝合金弯头冷推弯成形难度大、缺陷较多的问题,本文采用显式有限元分析软件ANSYS-LSDYNA对5754铝合金不锈钢弯头弯曲成形过程进行了有限元数值模拟,根据优化结果对合金管坯进行润滑处理,然后对铝合金弯头进行实际冷成形。结果综合分析表明,数值模拟和试验研究相结合是解决铝合金冷成形困难、制备高质量弯头管件的有效途径。     

基于ANSYS—LSDYNA有限元模拟的铝合金管件弯曲成形

为解决5754铝合金弯头冷推弯成形难度大、缺陷较多的问题,本文采用显式有限元分析软件ANSYS—LSDYNA对5754铝合金不锈钢弯头弯曲成形过程进行了有限元数值模拟,根据优化结果对合金管坯进行润滑处理,然后对铝合金弯头进行实际冷成形。结果综合分析表明,数值模拟和试验研究相结合是解决铝合金冷成形困难、制备高质量弯头管件的有效途径。     

钢制车轮轮辐旋压成形数值模拟和工艺参数优化

为指导车轮轮辐旋压成形工艺参数的选择，利用Simufact Forming对某款轻型客车的轮辐旋压过程进行有限元仿真，改进旋轮轨迹的确定方法，对比厚度仿真结果和实际加工结果，验证该仿真方法的有效性。在数值模拟的基础上，设计四因素三水平正交试验表，对工艺参数进行正交试验优化设计，得到一组针对该钢制车轮轮辐旋压成形的最优工艺参数。利用优化后的工艺参数进行轮辐旋压成形仿真，结果表明轮辐最大厚度偏差和最大等效应力都有所减少。     

覆盖件成形缺陷的数值仿真实例分析

为研究汽车大型覆盖件成形规律,并分析其缺陷成因,介绍了板料成形动态显式有限元数值仿真技术的应用现状、基本理论及应用步骤.通过实例研究了采用有限无数值仿真技术进行覆盖件成形缺陷成因仿真分析的途径.仿真结果表明,采用数值仿真可以分析覆盖件变形规律,了解冲压过程中应力、应变分布及方向,成形极限图分布及缺陷情况,进而改进模具结构和冲压工艺,消除成形缺陷、提高产品质量.数值仿真技术是解决大型汽车覆盖件成形缺陷问题的有效工具.     

基于ProCAST的支座件熔模铸造浇注系统设计

熔模铸造工艺开发需要开展大量的试制实验,其工艺研发成本高、周期久。论文基于支座件的试制结果提出了3套工艺优化方案,利用数值模拟软件ProCAST对优化方案的温度场与缺陷分布进行模拟分析并最终确定了可行工艺方案。试制结果表明,优化后的工艺方案可以使支座件实现自底向上的顺序凝固,可以得到无缺陷的铸件。     

PAM数值模拟软件

法国ESI集团PSI公司从70年代开始从事数值模拟软件的研究开发,主要是研究开发PAM系列软件产品。由于它把侧重点集中在应用方面,因此受到企业,特别是国际大公司的青睐。ESI集团PAM产品（PAMSYSTEM）主要包括：PAM－STAMP是板材成形数值模拟软件。对薄板成形件的成形结果进行分析、评价。帮助工程师进行产品工艺可行性研究和模具制造设计。PAM－STAMP还可以对吹塑成形、超成形、液压成形、橡皮模成形等成形工艺进行模拟。QUICKSTAMP是运用一步法对薄板成形件进行快速冲压模拟的数值模拟软件。该软件主要应用在模具设计…     

支撑座结构有限元仿真及优化

论文分析了铸钢支撑座产品的局限性,提出了一种用锻钢支撑座代替原有铸钢支撑座的新成形工艺。为验证新工艺的可行性以及降低产品开发周期及成本,作者利用通用有限元分析软件ANSYS对不同材料的同种结构支撑座、同种材料不同结构的支撑座进行结构受力分析,优化了锻钢支撑座结构,获得了安全系数较高的锻钢支撑座产品结构,利用数值仿真技术实现了锻钢支撑座新产品的开发。     

径向柱塞变量液压泵定子受力仿真分析

为了降低阻尼系数进一步提高泵的动态性能,通过对JBP-63型径向柱塞变量泵定子受力仿真分析,研究了减小径向柱塞液压泵的定子不平衡力的方法.依据泵的实际工作状况,利用simulink逻辑运算模块实现了定子受力的数学关系建模.仿真模型解决了复杂的三角函数计算过程,仿真结果得到了泵的定子受力曲线和滑履偏摆角的曲线图,结果表明定子在垂直方向受力很大,应用吸油区压力平衡窗口的方法可以显著减小垂直径向力.本方法对于系统结构参数设计和性能分析有一定应用价值.     

Investigation of an efficient shape optimization procedure for centrifugal pump impeller using eagle strategy algorithm and ANN (case study: slurry flow)

Investigation an efficient shape optimization method for centrifugal pump and other turbo-machine is significant to reduce time consumption of process and increase accuracy and modification. For analysis an efficient shape optimization procedure, slurry flow in centrifugal pump is investigated. Since a centrifugal water pump has been not designed to carry out slurry flows, its performance decreases and energy consumption of this kind of pump increases. Therefore, improvement of performance and reduction of energy consumed for these pumps are the major issues. Since the performance of a centrifugal pump strictly depends on its impeller shape, in this study, the shape of impeller was optimized in order to achieve a higher efficiency for slurry flow. To optimize the impeller geometry and to improve the performance of Berkeh 32–160 pump as for the case study, Artificial Neural Networks (ANN) and Eagle Strategy (ES) algorithms have been coupled with a validated 3D Navier–Stokes equations for two phase flow based on Eulerian-Eulerian model. In the next step, the pump experimentally tested in an established slurry flow test rig in laboratory. Measured data were used to verify the numerical results of initial pump with slurry flow. Finally, the complete numerical characteristic curves of the pump with the optimized impeller were compared to the validated numerical characteristic curves of that with the initial impeller to verify optimization. An efficiency improvement of 3.33% at only 9.9% increasing of head has been obtained for optimized geometry. The results indicated a reasonable improvement in the optimal design of pump impeller and a higher performance using the ES algorithm. Furthermore the ES and PSO algorithm was compared and results shows that ES is efficient than PSO algorithm in this application and this methodology is more efficient than other surrogate methods.     

压电折叠梁微执行器的低电压优化设计

采用理论分析和有限元数值模拟相结合的方法,对压电折叠梁微执行器在低电压下工作时的器件结构进行优化设计。首先通过理论分析获得优化的器件结构参数,再通过有限元模拟验证理论分析结果。在器件设计中,通过综合考虑制造工艺、工作条件、器件应用的可靠性,对压电悬臂梁长度、单晶硅层厚度、折叠梁级数,以及工作电压进行折衷优化,获得低电压应用时最佳的器件参数。     

Numerical simulation of fluid added mass effect on a francis turbine runner

In this paper, a numerical simulation to analyze the influence of the surrounding water in a turbine runner has been carried out using finite element method (FEM). First, the sensitivity of the FEM model on the element shape and mesh density has been analysed. Secondly, with the optimized FEM model, the modal behaviour with the runner vibrating in air and in water has been calculated. The added mass effect by comparing the natural frequencies and mode shapes in both cases has been determined.The numerical results obtained have been compared with experimental results available. The comparison shows a good agreement in the natural frequency values and in the mode shapes. The added mass effect due to the fluid structure interaction has been discussed in detail.Finally, the added mass effect on the submerged runner is quantified using a non-dimensional parameter so that the results can be extrapolated to runners with geometrical similarity.     

Computation of magnetic field in an actuator

Design and optimization of an actuators based on magnetostrictive technology requires computation of the magnetic field. The “MS”-technology offers an attractive controllability with high power density. The magnetostriction is a reversible feature which can be used in various actuator layouts. The actuator performance depends on driving magnetic field and the particular magnetic properties of used materials. Good understanding of specific design constrains is required to define and to optimized a magnetostrictive actuator. The non-linear computation of the magnetic field using FEM software is vital for the finale experimental design of a low-frequency actuator. This paper presents results of magnetic field simulation with FEMM software package and experimental measurements of the magnetic flux density. Good correlation between the simulation results and experimental measurements has been achieved.     

板料多次拉深成形仿真过程关键技术研究

计算机仿真技术作为板料冲压成形的辅助工具,能够动态地反映板料与模具之间的相互作用以及板料实际变形全过程中的应力、应变及厚度变化及分布。文章针对多次拉深成形的特点和难点,分析了多次拉深成形计算机仿真的一般过程,阐述了多次拉深成形仿真过程中应注意的几个关键技术问题：几何模型的建立、网格划分、屈服准则的选用、板料与模具间干涉问题的处理以及工序间变形历史信息的传递等。文章所阐述的关键技术对于多次拉深这一比较复杂的板料成形仿真应用、研究有较大的参考作用。     

Optimal operation of oil and gas production using simple feedback control structures

The purpose of this paper is to describe the control challenges related to optimal operation of oil and gas production wells, and show that optimal operation can be achieved using simple feedback control structures. In particular, we find that conventional feedback control structures can efficiently handle changes in active constraint regions using simple logics such as split-range and selectors. This eliminates the need for complex models to be used in the optimization problem, and in addition eliminates the need to solve numerical optimization problems online. Thus, by using only simple feedback controllers that have been used widely in the oil and gas industry, it has a higher chance of implementation. We demonstrate the use of simple feedback controllers on two application examples; 1) a gas-lift optimization simulation study with a network of six gas-lifted wells, 2) an experimental study of optimal control of electrical submersible pump (ESP) lifted oil wells tested on a large-scale experimental test facility with a full scale ESP and live viscous crude oil.     

基于CAD/CAE的卡扣模具快速设计与优化

为提高塑料卡扣模具设计的速度,利用ImageWare对塑料卡扣进行点云数据处理、特征线网格划分和曲面重构;将重构的塑料卡扣模型导入UG,借助UG的曲面修复功能缝合不连续的曲面,并以STL格式保存;利用UG的Mold Wizards模具设计模块,根据已保存的STL格式卡扣模型建立模具装配模型,设计分型面,生成模具成型零件的三维实体模型;用Moldflow/MPI进行塑料卡扣注射成型分析.结果表明采用优化后的模具设计参数与实验结果基本吻合。