【摘要】 统一强度理论是在中国本土原创产生和发展起来的关于材料强度和结构强度的系统新理论。它从连续统力学最基本的单元体力学模型开始,到数学建模方法,理论公式的表述,以及一系列新的理论公式都不同于以往的各种理论。它将以往各种适合于某一类材料的单一强度理论推进为可以适合于多种材料的统一强度理论。经过40多年的发展,它不仅自己形成了系统的理论,而且将很多著名的理论包容其中,形成了范围更宽广、功能更强大的理论体系。由于它具有一个统一的力学模型,清晰的物理意义,简单的线性数学表述式,能反映材料的基本特性,即SD效应(不同的抗拉强度和抗压强度)、静水应力效应、正应力效应、中间主应力效应和中间主剪应力效应,以及结构强度分析的破坏准则效应,并且与现有的实验数据相吻合,能容易地适合许多新情况;此外,统一强度理论既容易用来取得解析解,也容易用于计算机程序取得数值解。统一强度理论已被推广应用于很多领域。在连续介质和工程应用的框架下对统一强度理论的发展及其在土木工程中的应用和经济意义进行较为系统的小结。更多还原

【Abstract】 Strength theory deals with the yield and failure of materials under the complex stress state.It is an important foundation for research on the strength of materials and structures.It is of great significance in theoretical research and engineering application,and is also very important for the effective utilization of materials.Particularly for design purposes,it is important that a reliable strength prediction be available for various combinations of multiaxial stresses.Unified strength theory is a new systematic theory.The SD effect(strength difference in tensile strength and comp-[GK2]ressive strength of materials),effect of normal stress,effect of hydrostatic stress,effect of intermediate principal stress and the effect of failure criterion on the results of structural analysis are taken into account in the unified strength theory.The unified strength theory was originated and developed in Xi’an.It is developed and applied by many researchers in China,Japan,Singapore,USA,Australia,Sweden and others.This paper presents a summary of the advances of the unified strength theory and its applications in civil and hydraulic engineering;including unified slip line field(plane strain),unified characteristic line field(plane stress and spatial axisymmtric structures),unified solutions of limit analysis of plates,shells and other structures.The advances in the unified strength theory are summarized on the framework of continuum and engineering application.The detail of the unified strength theory can be found in a new book published by Springer recently(YU Mao-hong,Unified Strength Theory and Its Applications.Berlin,Springer,2004).The comment of Springer to the unified strength theory is as follows:“It is completely new theory dealing with the yield and failure of materials under multi-axial stresses.It provides a system of yield and failure criteria adopted for most materials,from metallic materials to rock,concretes,soils,polymers etc.The unified strength theory has been applied successfully to analyze the elastic limit,plastic limit capacities,the dynamic response behavior for some structures under static and moderate impulsive load,and may be implemented in some elasto-plastic finite element computer codes.The unified strength theory is described in detail and by using this theory a series of results can be obtained.The unified strength theory can improve the conservative Mohr-Coulomb theory,and since intermediate principal stress is not taken into account in the Mohr-Coulomb theory and most experimental data is not pertainable to the Mohr-Coulomb theory,a considerable economic benefit may be obtained.The book can also increase the effect of most commercial finite element computer codes.更多还原