【作者】 杜文风；

【导师】 董石麟； 高博青；

【作者基本信息】 浙江大学 ， 结构工程， 2007， 博士

【摘要】 随着空间网壳结构向着跨度更大、体系更复杂、设备更昂贵、影响更深远的方向发展，结构在地震、台风等灾害作用下产生的经济损失日益巨大，这一新特征已引起许多学者的广泛关注和深刻反思。本文针对上述问题，从基于性能的设计思想出发，综合空间网壳结构的具体特点，动力失效理论和基于概率的荷载及组合理论，建立了基于性能的空间网壳结构设计理论研究框架，并进行了深入研究。空间网壳结构动力失效理论和基于概率的荷载及组合理论是实现性能化设计的基础。本文在现有成果的基础上，对网壳结构动力失效理论作了进一步研究。阐述了网壳结构动力失稳和动力强度破坏这两种可能的失效机理；针对动力失稳，提出了一种新的判定准则-应力变化率准则；针对动力强度破坏，提出了能量与变形的双控准则，并给出了动力破坏指数这一新的指标。对不同跨度、不同矢跨比的单层Keiwitt型网壳结构的动力失效全过程、失效机理和失效特征进行了数值计算和深入分析，通过理论研究和前人试验结果，将单层Keiwitt型网壳结构的动力破坏程度划分为基本完好、轻微破坏、中等破坏、严重破坏、倒塌五个状态，并建立了相应的分界指标。本文在前述研究成果的基础上，对空间网壳结构的寿命周期总费用评估和基于投资-效益准则的优化设计方法进行了深入的研究。通过分析网壳结构的组成、材料单价，建立了网壳结构初始造价的计算模型。针对现有网壳结构维护费用的调研，建立了计算维护费用的数学模型。在深入研究网壳结构动力失效理论的基础上，结合工程价值、社会价值等多角度的分析，建立了失效费用的计算方法。在此基础上应用APDL语言编制了基于ANSYS的网壳结构寿命周期总费用的计算流程和应用程序。本文分析了空间网壳结构基于投资-效益准则的非线性、多变量、少约束、离散变量的优化设计特征，并且证明了在用钢量相同的情况下，按满应力原则配置的空间杆系结构的刚度最大，进而提出了综合考虑结构初始造价、维护费用及失效后果的全局优化设计的满应力调控法。该方法通过引入调控系数λ来调控满应力设计时的控制应力，并获得分别取不同的调控系数时按照满应力设计的结构配置方案，再计算这些结构配置方案的寿命周期总费用，最后从中选择最小者即为最优方案。应用上述寿命周期总费用的应用程序和满应力调控法便可计算获得以寿命周期总费用最小为优化目标的空间网壳结构，以及相应的最优目标可靠指标、目标控制位移、最优矢跨比等参量。本文应用上述理论研究成果对单层Keiwitt型网壳结构进行了全面分析，并同现行规范设计方法进行了比较，提出了基于性能的结构重要性系数的概念，并在大量数值分析的基础上给出了基于性能的单层Keiwitt型网壳结构重要性系数的参考数值。在现行设计方法中使用基于性能的重要性系数，可实现性能化设计与现行规范方法的有效结合。本文将基于性能的设计思想引入到空间结构领域，并进行了探索性的研究，得到了一些有益结果和结论。这些研究成果可供实际工程、现行规范和进一步研究参考，同时为网壳结构全面实现性能化设计提供了有价值的依据。更多还原

【Abstract】 With the developments of spatial latticed shell structures towards larger span, higher height, more expensive equipments and deeper influence, the losses of buildings caused by the disasters are becoming more terrible. Many scholars’ have paid abroad attentions to the new problem.To this problem, the study frame of the performance-based design theory of spatial latticed shell structures is constructed according to the idea of performance-based design and the characters of spatial latticed shell structures in this paper. The study frame synthesizes the idea of performance-based design, the theory of dynamical failure and the theory of loads and their combinations. Thorough and specific researches are carried out in the following chapters of the paper.The theory of dynamical failure of spatial latticed shell structures and the theory of loads and their combinations are the bases of performance-based design theory. Therefore, the exploring researches on the theory of dynamical failure are presented after the research advances are summarized. The paper expounds the two kinds of failure mechanisms of spatial latticed shell structures subjected to dynamic actions, the dynamic instability and the dynamic strength failure. Aiming at the problem of dynamic instability, a new judgment method—stress rate method is proposed. About dynamic strength failure, a double control criterion based on maximum displacement and plastic accumulative dissipated energy is proposed. Moreover, the dynamical failure index is presented to judge the different extent of dynamical strength failure of spatial latticed shell structures. The whole process, mechanism, and characters of dynamic failure of spatial latticed shell structures with different initial parameters are analyzed roundly. According to the theory researches and experiments accomplished by foregone scholars, the five levels (good condition, slight damaged, middling damaged, seriously damaged, collapse) of spatial latticed shell structures are proposed, and the corresponding dividing indexes are presented.Then, this paper presents exploring and deep researches to the evaluation of lifecycle-costs of spatial latticed shell structures and cost-effectiveness criterion based optimum design methods. The mathematics model for calculating initial building cost of spatial latticed shell structures is proposed by analyzing the structural constitutes and unit price of materials. The mathematics model for calculating maintenance cost of spatial latticed shell structures is established by investigations to latticed shell structures in existence. The calculating method of failure costs of spatial latticed shell structures is constructed by analyzing the engineering value and society value after the exploring researches on the theory of dynamical failure. Furthermore, the calculating process and applying program of lifecycle-cost calculation are accomplished.The characters of nonlinear, many variables, few constraint, disperse variables for optimum design of spatial latticed shell structures are analyzed. The paper proves that the stiffness of spatial truss structure is largest configured by the full stress principle with the same quantity of steel, and then a full stress adjusting optimum method is proposed, which considers structural building cost, maintenance cost and failure cost synthetically. The method quotes adjusting coefficient λ. to adjust the control stress of full stress design, and obtains the structural configurations of full stress design with different coefficient λ.. Then the lifecycle-costs of these configurations are calculated and the minimum is the optimum configuration. By applying the above calculating program of lifecycle-cost and full stress adjusting optimum method, the optimum spatial latticed shell structures are achieved which take the least lifecycle-cost as target, and the corresponding optimum parameters such as target reliability index, target controlling displacement, rise-span ratio, and so on, are achieved too.The paper provides comprehensive analysis to the Keiwitt single layer latticed shell structure according to the above theory and methods, and comparison between the results and those of Chinese national codes are carried out. The concept of structural performance-based importance coefficient is put forward and corresponding reference values are provided too. So the idea of performance-based design is embodied by structural performance-based importance coefficient, and Chinese national codes and performance-based design are integrated effectively.This paper introduces the idea of performance-based design to the field of spatial structures, and some groping research works is accomplished. Some useful results and conclusions are obtained, which are referenced to practice engineering, guild regulations and further researches. This paper provides some valuable references to fulfill the whole performance-based design of spatial latticed shell structures.更多还原