若干功能材料性能优化建模方法研究

通过对稀土荧光粉，ＶＰＴＣ材料，镍氢电池阴极材料的优化建模计算，研究和比较了线性ＰＬＣ方法，加非线性项的ＰＬＣ方法和加非线性项的ＰＬ－ＳＡＮＮ方法建模的效果。结果表明：当材料，性能和影响性能的因子间非线性较为严重时，加非线性项的ＰＬＳ－ＡＮＮ方法建模的效果较好，其预测结果和实测结果相当符合。     

橡胶悬置元件结构参数优化设计方法

由于橡胶悬置元件的结构比较复杂,截面不规则,无法用传统的优化方法对其结构优化.利用遗传算法和神经网络相结合的策略对橡胶悬置元件的几何结构参数进行优化,即用神经网络学习算法建立橡胶悬置元件几何结构参数与其三个方向刚度的非线性全局映射关系,获得遗传算法求解结构优化问题所需的目标函数,用遗传算法进行优胜劣汰的寻优搜索运算,求出最优解.优化结果表明,橡胶悬置元件结构参数优化设计方法是可行的.     

A CONTRIBUTION TO THE OPTIMAL DESIGN OF RIDE-RINGS FOR INDUSTRIAL ROTARY KILNS

The design of the ride-rings, or tyres, of industrial rotary kilns is studied as a nonlinear programming problem. The method of monotonicity analysis is employed to obtain results of sufficient generality and utility to the designer. A special-purpose algorithm for the location of the global optimum is presented. A parametric study provides design charts showing the range of criticallity for the various design requirements.

The article represents the type of modeling analysis and subsequent solution, suitable for design problems which must be solved many times with parameter changes larger than those handled with the usual sensitivity analysis.     

基于罚函数SPH新方法的水模拟充型过程的数值分析

同传统的网格法相比,光滑粒子流体动力学(SPH)方法非常适合于求解大变形和自由表面流动问题.阐述了SPH理论及其应用,并用罚函数处理流体与壁面的相互作用,以解决传统SPH本质边界条件不易施加的问题.对水模拟的允型过程实验进行数值分析,并和文献实验结果以及传统SPH进行对比,最终表明仿真结果与实验非常吻合,比传统SPH方...     

多用途PC卡设计

本文介绍了一种集A/D转换、D/A转换、定时器/计数器及DI/DO于一体的多功能PC总线计算机接口卡的设计原理与结构。这块接口卡是在存储测试技术中长期使用的数据传输接口卡的基础上加以改进扩充而制成的。本卡具有功能强、软件丰富、成本低、使用方便等特点。     

A MATHEMATICAL CONVERGENCE ANALYSIS OF THE CONVEX LINEARIZATION METHOD FOR ENGINEERING DESIGN OPTIMIZATION

This paper is concerned with the convex linearization method recently proposed by Fleury and Braibant for structural optimization. We give here a mathematical convergence analysis or this method. We also discuss some modifications of it.     

半导体制冷优化设计方法的析

对半导体制冷优化设计的两种方法进行理论分析,导出使制冷量和制冷系数分别达到最大值时的电流值,并由此得出设计所用主要参数,为半导体制冷器的优化设计提供技术支持.     

OPTIMAL DESIGN OF STRUCTURES WITH LARGE DEFORMATIONS ALLOWED FOR

The paper points out the necessity of taking into account large deformations in the process of optimal design, whenever they may be expected. The problem is presented via two examples of bars under nonuniform tension and of a Mises truss. Two cases of the constitutive laws: independent of time, and rheological, are considered,     

连续梁结构损伤识别的改进柔度阵方法

传统柔度阵方法难以指示多跨连续梁这样一些复杂连续体结构在支撑处的损伤,提出以结构柔度阵某些自由度对应的对角元素的变化率作为损伤指示函数,对多跨连续梁结构进行更为有效的损伤识别。识别的机理是利用损伤指示函数对于单元损伤因子灵敏度矩阵的对角占优特性,产生对损伤因子分布的“覆盖效应”,从而反映出结构损伤的状态特征。文中给出有关计算公式,进行了数值模拟并比较几种状态的损伤识别结果,显示了本文方法的合理性。     

结构优化设计中的灵敏度分析

阐述了灵敏度分析在带有频率约束的结构优化设计中的重要性，并且指出主模态局部化与非经典系统的灵敏性是结构设计师需要研究的课题。     

非线性结构利用摩擦阻尼器振动控制的优化设计

研究了强烈地震作用下非线性结构中摩擦阻尼器的参数优化问题。非线性结构的恢复力和摩擦阻尼器的滞回特性分别用连续的Bouc-Wen模型表示,利用遗传算法以相对性能指标为目标函数对阻尼器的参数进行优化,比较了不同地震波下摩擦阻尼器的减震效果。取一个八层结构为例进行计算,结果表明,摩擦阻尼器能有效地减小非线性建筑结构在强烈地震下的响应,Bouc-Wen模型能够较好地模拟摩擦阻尼器的滞回性能,使用遗传算法优化后摩擦阻尼器的参数,提高了结构的减震效果。     

STRIP DISTRIBUTED TRANSFER FUNCTION METHOD FOR ANALYSIS OF PLATES

A semi-analytical method, called the strip distributed transfer function method, is developed for analysis of plate structures that are composed of rectangular plates. In the method, a rectangular plate (substructure) is divided into a number of strips; the response of each strip is interpolated in the unknown nodal line displacements, which are functions of the strip longitudinal co-ordinate and time. The nodal line displacements are determined in an exact and closed form by the distributed transfer functions that are defined along the strips. Synthesis of the substructures using the strip distributed transfer functions yields accurate prediction of the static and dynamic response, natural frequencies and buckling loads of the structure. The proposed method is compared with some existing techniques in numerical examples.     

弹性曲梁问题的直接法

本文将哈密尔顿体系引入到极坐标下的弹性力学平面问题．利用该体系辛空间的正交归一等性质，将问题化为本征值和本征向量求解上，从而改变了弹性力学传统的半道法解决问题的思路，建立了一条求解该类问题的直接法．     

结构振动响应逐步逼近模糊优化设计方法

本文研究了受任意确定性载荷作用下,结构振动响应的逐步逼近模糊优化设计方法,利用构造逐步逼近的动态目标隶属函数,使多目标振动响应优化问题转化为单目标优化,并使其获得工种满意解的优化效率大为提高。     

OPTIMAL DESIGN FOR NON-STEADY-STATE METAL FORMING PROCESSES—I. SHAPE OPTIMIZATION METHOD

We suggest a shape optimization method for a non-linear and non-steady-state metal forming problem. It consists in optimizing the initial shape of the part as well as the shape of the preform tool during a two-step forging operation, for which the shape of the second operation is known. Shapes are described using spline functions and optimal parameter values of the splines are searched in order to produce, at the end of the forging sequence, a part with a prescribed geometric accuracy, optimal metallurgical properties and for a minimal production cost. The finite element method, including numerous remeshing operations, is used for the simulation of the process. We suggest using a least-squares-type algorithm for the unconstrained optimization method (based on external penalty) for which we describe the calculation of the derivatives of the objective function. We show that it can reduce to calculations which are equivalent to the derivative calculations of steady-state processes and to evolution equations. Therefore, the computational cost of such an optimization is quite reasonable, even for complex forging processes. Lastly, in order to reduce the errors due to the numerous remeshings during the simulation, we introduce error estimation and adaptive remeshing methods with respect to the calculation of derivatives.     

弹性剪切连接组合梁的应力计算方法

在桥梁结构中组合梁的弹性计算是一项重要的内容,然而要精确计算组合梁在弹性剪切连接(即有滑移)时的应力,须用到微分方程的解析解,在简单荷载作用下的静定结构还可得到这些解析解,但当荷载形式较复杂或为超静定结构时,要得到解析解就很困难了.目前还没有即简便,精度又高的实用计算方法,在<钢结构规范>[1](GB50017-200...     

FAIL-SAFE OPTIMAL DESIGN OF STRUCTURES

In this paper, a new class of structural design problems is defined. The problem is to design a structure that is safe, even after certain damage conditions are imposed. A generalized steepest descent algorithm is developed for solution of this class of problems. The algorithm is used to optimize a three member, a four member and a seventy-two member structure under stress, displacement, buckling, natural frequency, and design [vdot]ariable constraints and subjected to multiple loading conditions.