Friction aided deep drawing using newly developed blank-holder divided into eight segments

A new process on friction aided deep drawing has been developed in which a metal blank-holder divided into eight fan-shaped segments is used instead of an elastomer ring used in the Maslennikov process. This blank holding device consists of four drawing segments and four small wedges, which can move radially in- and out-wards under a certain blank-holding pressure. The drawing process can be efficiently performed using an assistant punch, which partially supports the deformation of the blank as well as improving the shape and dimensional accuracy of the drawn cup. Deep drawing experiments have been done using soft aluminum sheets of 0.5 and 1.0 mm in thickness to understand the main features of the proposed drawing process. Theoretical analyses based on the energy and slab methods have also been conducted to study the effect of main process parameters on the minimum blank holding pressure required for the onset of deformation, and to obtain the other optimum working conditions. The possibility of the new process has been confirmed by producing deep and successful cups with a drawing ratio of 4.0, although the number of drawing operations is still high.     

新的嵌套排样算法

以多边形定点算法原理为基础，得出了新的嵌套求解算法成功解决了优化排样问题。并以C语言程序设计为基础，使算法在计算机上得以实现。     

Surface reconstruction for incremental forming

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.     

Development of a Five-axis Milling Tool Path Generation Algorithm based on Faceted Models

This paper describes the development of a 5-axis milling tool path generation algorithm based on faceted or tessellated models. In a first step, the developed algorithm optimises the tool inclination angle for maximal material removal rate in each cutter contact point. This is obtained by matching the tool profile of a flat end cutter with a temporary spline representing the curvature of the part surface in the tool contact point. In a second step, the elimination of gouging between the tool and the surface and a smooth behaviour of the tool inclination angle along the tool path is obtained by a combination of tool inclination angle adaptation and tool lifting along the normal vector. Finally, the paper describes some experimental results.     

二切分带肋钢筋计算机辅助孔型设计

在进行带肋钢筋切分轧制时,孔型设计中存在形状选择、尺寸计算等难点,为此编制了一套切分轧制带肋钢筋计算机辅助孔型设计系统。分析了二切分带肋钢筋计算机辅助孔型设计系统的特点及双斜哑铃孔的优越性,并介绍了其轧件面积的计算方法。     

SCARA型机器人仿真避障算法的研究

根据机器人的运动学分析模型对机器人进行动态仿真是机器人设计过程的一个重要环节.文章对SCARA型机器人进行了运动学分析,建立了该类型机器人的运动学模型,提出了SCARA型机器人避障仿真算法,并对其进行了计算机仿真与分析,这对机器人运动学、动力学、微机控制和路径规划等方面的研究有重要的参考价值.     

双动压力机多杆机构的计算机辅助运动分析

运用连杆机构分析的基本组法，开发了双动压力机多样机构计算机辅助分析的通用程序包，对于不同形式的多杆机构，通过其主程序与此程序包联结，可方便有效地完成机构运动的分析计算和动态模拟，并且给出了实例说明。     

交互更新模式的量子遗传算法的几何约束求解

目的针对传统量子遗传算法无法充分利用种群中未成熟个体信息的不足,提出了基于交互更新模式的量子遗传算法(IUMQGA)并应用于几何约束求解中。方法几何约束问题的约束方程组可转化为优化模型,因此约束求解问题可以转化为优化问题。采用将遗传算法与量子理论相结合的量子遗传算法,使用双串量子染色体结构,使用交互更新策略将遗传算法中的交叉操作利用量子门变换来实现,根据不同情况采用不同的交互更新策略。这里的交互,指的是两个个体进行信息交换的过程,该过程用以产生新的个体。这不仅增加了个体间信息的交换而且充分利用了种群中未成熟个体的信息,提高了算法的收敛速度。结果通过非线性方程实例和几何约束实例测试并与其他方法比较表明,基于交互更新模式的量子遗传算法求解几何约束问题具有更好的求解精度和求解速率。双圆外公切线问题实例中,IUMQGA算法比QGA算法稳定;单圆填充问题和双圆外公切线问题实例中,通过实验求得各变量的最优值与其相应的精确值的误差在1E-2以下。结论采用交互更新模式的量子遗传算法可以很好地求解几何约束问题。     

Tuning space mapping with tuning exponent of T‐matrix

Tuning space mapping (TSM) with tuning exponent parameter of T‐matrix is proposed. A section of design interest in the electromagnetic (EM) model is replaced by “n” pieces cascaded T‐matrixes, and each T‐matrix is the EM‐simulated T‐parameter of preassigned unit cell circuit (PUCC). Finally the optimal exponent parameter of T‐matrix is transferred to original design variables. The proposed TSM not only inherits the advantages of circuit tuning element‐less (CTEL) TSM in prior art but also overcome the number range limitation that the tuning parameter must be positive for tuning in CTEL TSM. The proposed method has the minimal specification error and lowest simulation time comparing with other TSM methods. Verification examples, comparisons and discussions are also implemented. © 2015 Wiley Periodicals, Inc. Int J RF and Microwave CAE 26:232–239, 2016.     

高校网络辅助教学探讨与研究

随着网络技术和信息技术的快速发展,在高校推广和开展网络辅助教学,为教师和学生构建一个开放的教、学、管三合一网络综合应用平台已成为现代教育信息化发展的一个必然趋势。文章对开展网络辅助教学的必要性进行了分析,介绍了网络辅助教学平台的基本功能,提出通过加强平台技术层面开发、提高教师教育信息技术能力、完善管理机制、有效整合网络资源、拓宽知识纵深度、实现资源共享最大化,可提高平台应用效果,以期对网络辅助教学发展提供参考和借鉴。