题目：从线性弹性到非线性直接分析：在结构钢设计中的三十年教学、研究与实践的奉献

From linear elastic tononlinear direct analysis for structural steel design – 3 decades devotion inteaching, research and practice

时间：2024年11月22日周五14：30－15：30

      地点：7号楼7201会议室

      报告人：陈绍礼, 智慧城市学院，土木与交通学院教授

      主持人：赵俊贤教授（华南理工大学土木工程系）

      欢迎广大师生参加！

土木与交通学院

2024年11月18日

报告人简介：

陈绍礼教授曾是香港理工大学计算结构工程系的讲席教授，直至2022年。随后担任了Nida科技有限公司的董事，并在2024年加入华南理工大学。他从事钢结构、组合结构和混凝土结构的稳定性设计、非线性有限元分析、玻璃和细长结构、岩石和防洪屏障、竹制和铝制脚手架以及预应力钢结构等方面的研究。在过去的三十年中，陈教授开发了一种新的设计方法——二阶直接分析法，该方法考虑了在实际构件中存在的几何缺陷，避免了规范中有效长度假设的不准确性和查询图表的冗杂性。自1998年以来，他将这种方法应用于多个钢结构和组合结构的设计中，包括香港、澳门、缅甸、新加坡、英国等地的许多标志性钢结构项目，其中包括2008年和2016年在香港获奖的项目，以及澳门美高梅的屋顶天幕，该屋顶被吉尼斯世界纪录收录为世界上最长的单层钢网壳结构。陈教授担任3个国际期刊的主编和7个其他期刊的编委，同时担任香港工程师学会结构部、结构学科和消防部的主席。

Professor S.L. Chan had been the Chair Professor inComputational Structural Engineering at the The Hong Kong PolytechnicUniversity until 2022, then took the position as Director of Nida TechnologyLimited in Science Park in Hong Kong and joined The South China University ofTechnology in Guangzhou in 2024 as a Professor to continue his research instructural stability, advanced design of steel, composite and concretestructures, nonlinear finite element analysis, glass and slender skeletalstructures, steel, rock and flood barriers, bamboo and aluminum scaffolding andpre-tensioning steel structures.  Duringthe past three decades, Professor Chan developed a new design methodsecond-order direct analysis allowing for imperfections in practical structuresbypassing the effective length assumption and the prescriptive use of chartsand tables in Code. Since 1998, he applied the method in cooperation with hisstudents and co-workers to the design of a number of steel and compositestructures which include numerous iconic steel structures in Hong Kong, Macau, Myanmar,Singapore, UK etc. including the 2008 and 2016 award winning projects in HongKong and the “Spectacular Roof” for MGM Resorts, being archived in Guinnessrecord as world’s longest single layer steel space frame.  Further Professor Chan has delivered numerouskeynote in local and overseas conferences and symposia and acted as chiefeditor of 3 international journals and member of board for other 7 journals. Hewas also a chairman of structural division, structural discipline and Firedivision of HKIE.

报告摘要：

分叉和有限挠度稳定性分析是两种核心的稳定性理论，它们分别衍生出了一阶线性和直接分析的设计方法。在分叉理论中，设计依赖于未变形结构的假设屈曲模式，针对特定载荷情况，所有柱子都具有各自的有效长度。然而，有效长度法的准确性有限，因为实际上没有结构能在无挠度的未变形状态下发生弹性屈曲，而且错误地假设有效长度可能会带来严重后果。相反，二阶直接分析法允许结构存在初始缺陷，通过分析预测结构在不同极限状态下的稳定性和强度。后者自被纳入中国大陆的GB50017规范、美国的LRFD规范、欧洲的Eurocode-5以及香港钢结构规范以来，被广泛认为是比有效长度法更优越的首选方法。直接分析法的明显优势在于，它避免了过度设计冗余构件和不足设计关键构件的问题，并且能够合理地处理结构在如火灾和地震工程、渐进分析、荷载序列研究等工况下的设计。本次研讨会将介绍直接分析法的理论基础和对实际应用的考量，展示其在复杂结构设计中的应用，还将分享在该方法的研究、教学和应用方面的经验。

Bifurcation and finite-deflection stabilityanalyses represent two general stability theories and they lead to thefirst-order linear and direct analysis methods of design for checking ofstructural stability and capacity. In the bifurcation approach, design is basedon an assumed buckling mode at undeformed structural geometry for a specificload case and all columns have their own effective lengths and bucklesimultaneously in concept. The effective length method of design has limitedaccuracy since no practical structures could have elastic buckling atundeformed state without deflections and the error of assuming an incorrecteffective length by manual inspection could be catastrophic. In contrast, thesecond-order direct analysis method allowing for imperfections used forstability design of steel and other structures uses an analysis to predict thestability and strength of a structure which is loaded to the various limitstates.  This method of design wasproposed by the speaker decades ago and has been well received by the designprofession as a superior and preferred alternative to the effective lengthmethod since its introduction in the design codes GB50017 in Mainland, LRFD inU.S., European Eurocode-5 and Hong Kong steel code decades ago. The obviousadvantage of the direct analysis includes redundant members not over-designedand critical members not under-designed and it could deal with design ofstructures rationally under different scenarios like fire and seismicengineering, progressive analysis, load sequence studies etc. This seminarpresents the theoretical background with practical considerations of the directanalysis method of design with benchmark and practical examples given on itsconcept and practical application to complex structures beyond theapplicability of the effective length method. Experience in research teachingand application of the method will be shared in this seminar.