History of the stiffness method

This paper presents a brief history of the development of the stiffness method. We start by tracing the evolution of the method to solve discrete‐type problems such as trusses and frames composed of two node members. We then describe the method as it is applied to solve continuum problems modelled by finite‐difference and finite‐element methods. Copyright © 2006 John Wiley & Sons, Ltd.     

Procedure for the evaluation of the accumulation of defects in metallic structural materials under complex elastoplastic loading

Within framework of the continual fracture mechanics, we describe the engineering approach to the assessment of scattered microdamage accumulation kinetics in metallic materials under elastoplastic loading conditions in case of plane stressed state. Automatized experimental stand and the respective investigation technique are discussed. The stand has been developed based on modification of the UMé-10T electromechanic test machine. State-of-the-art computer technologies and microprocessing hardware are incorporated in the stand automation. We present the technique of experimental assessment of damage accumulation kinetics in metallic structural materials under complex elastoplastic loading conditions with account of two different fracture (cleavage and shear) processes, which technique is based on measuring the specific electric resistance of the specimen. __________ Translated from Problemy Prochnosti, No. 1, pp. 128–137, January–February, 2006.     

田陈矿选煤厂煤泥水系统技术改造

分析了田陈矿洗煤厂煤泥水系统现状及存在问题,针对煤泥水系统的问题提出了改造方案。     

Determination of Flow Curves at High Strain Rates using the Electromagnetic Forming Process and an Iterative Finite Element Simulation Scheme

The knowledge of reliable material parameters is an essential requirement for the numerical analysis and planning of forming processes, especially when using high speed forming processes in industry. Therefore, a method was developed and implemented to determine the relationship between yield stress, plastic strain, and strain rate of aluminium alloys at very high strain rates of up to 10,000 s-1 by using the electromagnetic forming process (EMF) of tubular specimens. To determine the associated flow curves, an inverse engineering strategy combining an online measurement technique and multi-physical coupled finite element simulations is used. The results are discussed with regard to the anisotropic behaviour of specific aluminium alloys.     

级进模两步法冲裁模设计要点

从寻求发挥多工步冲裁优越性的角度出发,通过试验测试,证明了以第1工步为半冲裁、第2工步为推料的两步法冲裁,能消除自动化冲压加工中的废料上行和废料堵塞,降低冲裁工艺噪声。提出了实现两步法冲裁级进模的结构,包括两工位两工步及三工位两工步级进冲裁模的4种具体结构,并给出了其设计要点。     

Material constant sensitivity boundary integral equation for anisotropic solids

In this paper, the material constant sensitivity boundary integral equation is presented, and its numerical solution proposed, based on boundary element techniques. The formulation deals with plane problems with general rectilinear anisotropy. Expressions for the computation of sensitivities for displacements, tractions, strains and stresses are derived, both for boundary and interior points. The sensitivities can be computed with respect to the bulk material properties or to the properties of part of the domain (inclusions, coatings, etc.). To assess the accuracy of the proposed approach, the computed results are compared to analytical ones derived from exact solutions obtained by complex potential theory, when possible, or finite difference derivatives otherwise. Copyright © 2005 John Wiley & Sons, Ltd.     

苏州河河口水闸工程设计特色

在简要介绍苏州河河口水闸工程设计背景及工程概况基础上,从闸址选择、工程标准与规模论证、闸门门型选择、总体结构方案论证、施工组织设计、环境保护、工程效益论证等各方介绍了工程设计特色,并从满足多功能要求基础上介绍了水工、机电与金属结构方面设计存在的难点,从而为今后同类工程设计提供参考。     

美国节能管理工作特点及对我国的启示

本文比较系统地分析了美国节能管理工作的主要特点,并研究了美国的节能管理模式对我国推动节能工作的启示。文中首先介绍了美国推动节能工作的主要机构,然后从最低能耗标准、能效标识、节能工作参与群体的市场定位、基于市场的节能激励机制及政府机构节能等方面详细阐述了美国节能政策制定和实施的基本特点,并结合我国的国情分析了美国节能管理模式对我国节能工作的启示,最后提出了相关政策建议。     

水轮发电机转子动平衡的时-频方法

提出了一种基于时域分析和频域分析的动平衡方法，应用于水轮发电机转子的动平衡。在这种时-频动平衡方法中，用时域分析来确定不平衡力的相位，用频域分析来确定不平衡力的大小。该方法具有平衡精度高、起机次数少的优点。用1台300MW水轮发电机转子的现场试验数据验证了该方法的准确性和适用性。     

Using Lyapunov's direct method for wave suppression in reactive systems

This paper proposes a new approach for stabilizing a homogeneous solution in reaction–convection–diffusion system with oscillatory kinetics, in which moving or stationary patterns emerge in the absence of control. Specifically, we aim to suppress patterns by using a spatially weighted finite-dimensional feedback control that assures stability of the solution according to Lyapunov's direct method. A practical design procedure, based on spectral representation of the system and dissipative nature of parabolic PDEs, is presented.