Inelastic analysis-based design optimization of eccentrically braced steel frames

基于非弹性分析的偏心支撑钢框架设计优化

• 批准号: 288242-2006
• 负责人: Gong, Yanglin
• 金额: $ 1.31万
• 依托单位: Lakehead University
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2006
• 资助国家: 加拿大
• 起止时间: 2006-01-01 至 2007-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=332177
• 关键词: Inelastic; analysis; based; design; optimization

The objective of the proposed research is to develop an inelastic analysis-based design optimization methodology for eccentrically braced steel frames under earthquake loading.      The state-of-the-art design method for eccentrically braced frames (EBFs) is the capacity design approach, where the links are sized for code-specified forces while all other members are proportioned for the forces generated by the fully yielded and strain hardened links. The capacity design approach has four main shortcomings: 1) it is implemented by hand calculations instead of by computers; 2) it is unable to determine, with confidence, the internal forces for the columns in braced bays; 3) it cannot account for instability effect; and 4) it cannot identify inelastic behaviors outside the links.      These shortcomings of the capacity design approach can only be possibly overcome by employing an inelastic analysis-based design procedure. There exist two inelastic analysis methods for seismic design, i.e., nonlinear dynamic time history analysis and pushover analysis. None of these methods are pitfall free. Considering the relative simplicity of pushover analysis, this proposal will adopt pushover analysis as the main tool to evaluate seismic demands for EBFs, while the time history analysis is employed to verify the design solutions if necessary. In light of the tremendous computational efforts required for a design process using an inelastic analysis, a computer-aided tool specially developed for EBFs is indeed desirable.      Minimization of both structural weight and earthquake damage will be the design objective. The capacity design concept will be realized by imposing constraints on the plasticity demand for steel members. For example, yielding in the frame members outside the links will be prohibited, or strictly controlled if unavoidable.      The proposed research work will not only liberate design engineers from arduous hand calculations but also significantly improve the performance of the EBFs designed by the proposed methodology.

本研究的目的是发展一套以弹塑性分析为基础的偏心支撑钢框架在地震作用下的设计优化方法。 偏心支撑框架（EBF）的最新设计方法是能力设计方法，其中连杆的尺寸为规范规定的力，而所有其他构件的比例为完全屈服和应变硬化连杆产生的力。承载力设计方法有四个主要缺点：1）它是通过手工计算而不是通过计算机实现的; 2）它不能确定，与信心，在支撑的海湾柱的内力; 3）它不能考虑不稳定的影响;和4）它不能识别非弹性行为以外的链接。 容量设计方法的这些缺点只能通过采用基于非弹性分析的设计程序来克服。抗震设计中存在两种弹塑性分析方法，非线性动力时程分析和pushover分析。这些方法都有陷阱。考虑到pushover分析的相对简单性，本建议将采用pushover分析作为评估EBF抗震需求的主要工具，而在必要时采用时程分析来验证设计解决方案。鉴于使用非弹性分析的设计过程所需的巨大计算工作量，确实需要专门为EBF开发的计算机辅助工具。 最大限度地减少结构重量和地震破坏将是设计目标。通过对钢构件的塑性要求施加约束，实现承载力设计概念。例如，将禁止在连接件外部的框架构件中屈服，或在不可避免的情况下严格控制屈服。 所提出的研究工作将不仅解放设计工程师从繁重的手工计算，但也显着提高所提出的方法设计的EBF的性能。