FINITE ELEMENT SOLUTION OF A MODEL FREE SURFACE PROBLEM BY THE OPTIMAL SHAPE DESIGN APPROACH

Optimal shape design approach is applied to numerical computation of a model potential free boundary value problem. The problem is discretized using the finite element method. To test the approach the problem is formulated in both velocity potential and stream function formulation and four different finite element discretizations are used. Associated minimization problem is solved using the quasi-Newton method. Gradient of the cost function is computed by solving the algebraic adjoint equation. Gravity and surface tension forces are included in the model. Viability of the method is showed by solving problems with important effects of gravity and surface tension forces. © 1997 by John Wiley & Sons, Ltd.     

THE REGULAR INTERSTITIAL SOLUTION MODEL OF Fe-C SOLID SOLUTION

提出了用于Fe-C 固溶体的规则间隙溶体模型。该模型预言的C-奥氏体的平衡热力学性质同较完整的实验活度数据(900—1400℃)完全一致,并能较好地描述C 原子扩散系数随组分变化的动力学行为。结合C-铁素体的准规则溶体处理能满意地描述Fe-C 系富Fe 区γ/(α+γ),α/(α+γ)相平衡,与文献中的LFG,MD 处理相比该模型具有非常简单的数学表示形式。     

基于特征设计和参数设计的零件模型

为提高ＣＡＤ／ＣＡＭ系统的描述能力和效率，本文提出一种基于特征设计和参数设计的零件模模型。该模型采用了一系列新的表示方法，包括辅助点线面表示，工作坐标系表示、截面轮廓和轨迹表示、和零件模表示。辅助线面用于定位特征。     

在花的海洋中做设计

走进Artecnica的世界就如同来到了花的海洋里，各种以花和动物为主题和元素的产品设计扑面而来，在花的装饰中人们能立刻陷入陶醉。     

THE SOLUTION OF LARGE-SCALE GAS PIPELINE DESIGN PROBLEMS

The solution of large-scale gas pipeline design problems involving compressible fluid flow through tree networks is described. The problems are posed as large-scale nonlinear optimization problems. Two design situations are considered: with and without the possibility of compressors in the network. Computational experience on a number of problems is discussed.     

ROBUST DESIGN BY VARIABILITY OPTIMIZATION

A deterministic method of robust design against design parameter uncertainty is described. The method consists of the definition of a variability function for the performance measure under consideration, based on known or assumed uncertainties in the parameters of the measure and its known dependency on these parameters. It is assumed that the design parameters are subject to constraints on their individual values and interactions and that the performance measure (or output variable) is required to have a specified nominal design point value when the design parameters are at their chosen nominal values. An algorithm is then described which determines that set of nominal parameter values which results in a minimum value of the variability function given the specified constraints. The algorithm is applied to two examples, firstly in analytic form to demonstrate the procedure and then numerically to specific design problems. The results are discussed in relation to a probable design strategy and with regard to the advantages and limitations of the method employed. © 1997 by John Wiley & Sons, Ltd.     

探索适合亚洲的设计模式

“我们最有效的创意之一，就是我们为台湾地区市场，中国大陆市场和亚洲市场而特别开发的一步步的长级阶段，从OEM开始，经过ODM的不同阶段达到OBM，精确的表明了一个公司要想从一个地位上升到另外一个地位所必须经过的步骤。”[编者按]     

溶液聚合制聚丙烯酰胺/蒙脱土纳米复合材料

利用溶液聚合法制备了聚丙烯酰胺／蒙脱土插层复合材料。XRD、IR等表明，聚丙烯酰胺已进入蒙脱土层间，并使之剥离。DSC表明，剥离型纳米复合材料的热稳定性提高，这是由于蒙脱土纳米片层与基体大分子链相互作用的结果。研究结果表明，复合材料调湿性能优于基体材料。     

一种利用有限元反解技术的动态优化设计方法

探讨了将特征值问题的研究成果与传统的优化设计技术相结合以进行结构的动态设计的问题。提出应用有限元模型修正原理及有限元反解技术，将动态性能约束用设计变量显式表达，从而将困难的结构动态优化设计问题转化为普通的数学规划问题，方便于工程应用。实际算例表明，本文提出的方法切实可行