高层建筑带支撑钢框架结构动力可靠度理论

尽可能依据概率和可靠度理论开展设计是结构工程行业的必然要求，因为这样，才能使设计的结构既经济合理又安全可靠。随着高层和超高层钢结构的广泛应用，结构“柔”的问题愈显突出，研究这类结构的抗风和抗震可靠性及其振动控制，在理论上要面临很大挑战，经济上将会产生巨大效益。 本文研究高层建筑带支撑钢框架结构抗风抗震的非线性可靠度问题。首先，基于M.F.Giberson单分量模型推导出可考虑二阶效应，材料非线性及剪切变形的杆单元刚度矩阵；详细研究了节点区的受力变形特性后，把节点区变形的影响纳入到以上单元刚度矩阵中；利用杆系——层间模型，并通过直接刚度法建立了结构非线性振动方程，这一方程是迄今最完备且适用的高层钢结构动力方程。其次，在结构抗风随机动力分析的基础上，本文研究了抗风结构基于安全性和舒适性的可靠度适用算法；首次对安全可靠度和舒适可靠度进行对比研究，算例表明，就这两种可靠度而言，高层钢结构往往较易满足安全可靠度，但却较难满足舒适可靠度；舒适可靠度通常不被设计者关注，但却影响建筑的正常使用。再其次，本文严密推导了高层钢结构浅水TLD控制的计算理论，详细地分析研究了TLD各参数对控制减振效果的影响，并提出了TLD的优化设计方法，基于大量的数值分析，建议了TLD参数的适用取值范围；结合算例研究表明，TLD是经济有效的抗风控制装置。最后，针对现行抗震结构设计方法，本文建议高层钢结构抗震检验重点应放在“中震可修、大震不倒”方面；提出了结构屈服后整体刚度系数α与其相应的位移延伸率μ的关系式；采用等效线性化法推导出了结构随机地震反应的计算公式；以层间位移角极限为首次超越破坏机制的临界值，推导了结构抗震可靠度的计算公式；结合算例研究表明，二阶效应和场地类别对结构抗震可靠度具有显著影响。 本文开展的研究密切结合现行规范，所使用的有关参数均按规范取值，算例富有代表性且具实际工程背景，因而研究成果具有理论意义和工程实际意义。
电加热器
In order to get structures enough safe as wellas economical, engineers have to do designings according to the theories of probability and reliability as strictly as possible. With wide use of steel structures in tall and super-tall buildings, the problems of SOFT of structuers become more outstanding. It will face massive challenge in theory to study the dynamic reliability and controlling of anti-wind and anti-seismic structures, but great benefit may achieve in economy.This paper study nonlinear dynamic reliabilities of anti-wind and anti-seismic steel braced frames of tall buildings. Firstly, by using M. F. Giberson single component model, the element stiffness matrix possessing the second-order effect, material nonlinear and element shearing deformation is deduced. After studying in detail on the behavior of the panel, the effect of the panel deformation is brought into the relevant element stiffness matrix. With applying member-story vibration model and direct-stiffness method, the structural nonlinear vibration quation is established. Secondly,based on the analyses of random dynamic response of anti-wind structures, the structural reliabilities of safety and comfortability are studied contrastively. Combining with the caculation result of examples, it is found that steel tall-structures usually achieve reliability of safety more easy than that of comfortability. Comfortable reliability was generally ignored, however it impair the nomal usage of building. Thirdly, the dynamic response formulas of steel tall structure controled by TLD are derived; the effects of TLD’s parameters on the control efficency are analysed; an optimization procedure for the TLD’s designing is proposed; and suitable ranges of TLD’s parameters are given out. Caculation examples show that TLD is an efficrent and economical controlling device. Finally, the function concerning a (yield stiffness coefficient of stucture) with μ (displacement elongation of structure)is presented; thus formulas of equivalent stiffness and equivalent damper are obtained. After analysing eathquake-induced nonlinear random response, the relevant reliability is derived. In caculating examples, the effects of second-order and soil classification on the reliability are discussed.All of the studies in this paper are carried out according to current codes and the sampels are typical and applicable, so the deduced results are valuable both in theory and practice.