多层住宅新型复合结构的计算研究

【作者】 李海明；

【导师】 王新玲；

【作者基本信息】 郑州大学 ， 结构工程， 2005， 硕士

【摘要】 进入二十一世纪,我国住宅建设面临持续大发展局面,住宅产业已是带动整个国民经济发展的支柱产业和新增长点。而住宅结构体系的选择是影响住宅使用功能、造价和工期的重要课题。而用于多层住宅的砖砌体结构,由于粘土砖破坏耕地和环境,已被大部分城市禁止,因此需要研究新型结构体系。本文提出的是一种多层住宅新型复合结构体系,由钢筋混凝土柔性柱、柔性梁和钢或混凝土支撑组成的支撑结构体系代替原住宅中的承重砖墙及不开门窗洞的自承重墙,使住宅形成复合结构体系代替原砌体结构。为了满足住宅室内要求,梁柱截面应尽量小,如250×250～300mm以便隐藏于墙内。但住宅结构仅采用如此小截面的梁柱形成的结构无法满足承载力要求,因此本文通过加支撑达到目的。常用的支撑型式有X支撑、“人”字支撑及连续支撑,按材料不同分为混凝土支撑和钢支撑。新型复合结构体系最大特点是要求所加支撑首先要参与承受竖向荷载,使梁柱在竖向荷载作用下的内力大大减小(即竖向荷载作用下,支撑为梁的支点),同时支撑又使其在水平风荷载作用下的内力亦大幅度降低,从而满足承载力要求;最后在地震作用下支撑再起主要的抗震作用。选择合理的钢筋混凝土支撑截面可以形成“强柱、中梁、弱支撑”的多道抗震防线体系。 本文结合2-6层的一榀复合结构体系,运用有限元分析软件ANSYS对新型复合结构体系进行了以下方面的计算研究: 首先通过对复合结构体系的选型分析,优化出新型复合结构体系较合理的结构型式—梁柱加钢筋混凝土人字支撑;与一般框架比较,讨论复合结构体系的受力特点。考虑不同荷载组合的工况,计算分析了采用不同支撑截面的一榀复合结构体系的内力、变形反应,研究了支撑截面的影响。 采用《结构力学》、《结构动力力学》中的矩阵位移法推导了复合结构体系中的钢筋混凝土柱的刚度矩阵、钢筋混凝土梁的刚度矩阵、钢筋混凝土支撑的矩阵、结构整体刚度矩阵、节点位移、各单元杆端力。 然后对复合结构进行了动力性能理论分析,将复合结构体系简化为一个n自由度的层间剪切线性模型,推出了支撑刚度矩阵、柱撑层间抗侧刚度;以两层为例,分析研究了支撑抗侧刚度对复合结构动力性能(固有频率)的影响;并用有限元软件ANSYS对复合结构体系进行模态分析,和理论结果进行比较。 最后对复合结构进行了地震反应分析。运用ANSYS中的地震反应谱法,计算了复合结构体系在7度、8度多遇地震作用下的内力、变形,与静力作用下复合结构体系的内力进行了比较。选用EL-Centro地震波和一组人工地震波,用有更多还原

【Abstract】 Our country will be confront with the continuous boom of the residential construction in the 21th century. The residence industry has been the backbone industry which drives the whole national economy’ s development and new growth pole. Whereas the selection of residential structural system is the important theme which influents residential functions of use, cost and long-term .But the brickwork structure used for Multiple-story residence has been forbidden in most of cities for firebricks destroy tilth and environment. So the new structural system is required to research. In this paper, a new compound structural system Of Multiple-story residence is put forward. The compound structural system composed by reinforced concrete column, beam and steel or else concrete brace is suggested, and then substitutes for brickwork wall. In order to satisfy indoor requirement of residence, the sections of beam and column should be very small such as 250×250~300mm. So the beams and columns can be faded into wall. If the residence structure hardly adopts beam and column which have so small sections the structural bearing capacity can not be satisfied. So braces are added in this structure. The typical brace styles are X braces, "a" braces and continuous braces, and concrete brace and steel set according to stuff. The most trait of new style compound structural system is that added braces take part in boring vertical loads first of all. So that internal forces of beams and columns considerably would be lessen under vertical loads. Secondly the braces make internal forces of beams and columns reduce under horizontal wind forces, hence the bearing capacity can be satisfied. At last they have principal anti seismic function on earthquake’ s effect. Multiple anti seismic lines of defence systems having strong column, middle beam and weak brace will be formed by selecting rational reinforced concrete brace sections.In this paper, incorporated from two layers to six layers compound structural system, computational research on many aspects of new compound structural system proceeds handling finite element analysis software ANSYS ,there are:Through the lectotype analysis of compound structural system, relative rational structural style of new compound structural system with beams, columns and reinforced concrete "a" brace would be optimized. Based on comparing with general frame construction, mechanics traits of the compound structural system would be discussed. After different behaviors of combinations of loads are considered, the internal force and deformation of the compound structure which adopts different bracesection would be computed and analyzed, and the influence of brace sectionwould be researched.Based on ’structural mechanics’ and ’structural dynamics’ , the reinforced concrete column s Stiffness matrix, reinforced concrete beam s stiffness matrix, reinforced concrete brace s stiffness matrix, the whole structure s stiffness matrix, nodal displacement and elemental rod end force are obtained.The theoretical analysis of compound structure’s dynamic behaviour would put up. The compound structural system would be simplified to a interlaminar shear linear modal with n freedoms , and brace stiffness matrix and interlamination shear stiffness of column and brace would be deduct. The influence of brace shear stiffness on the compound structural dynamic behaviour that is free-running frequency will be analyzed and studied. At the same time modal analysis of the compound structural system would be proceed by ANSYS and compared with theoretical results.At last, the earthquake response analysis of compound structure would undertake. The compound structural internal force and deformation under the effect of 7 degree and 8 degree frequent earthquake would be calculated through the earthquake response spectrum law in ANSYS. And then the result would be compared with the results of the compound structural system under static force. EL-Centro seismic wave and a set of man-made seismic wave would be selected ,the elastoplastic time interval analysis of compound structural system would march by Newtn —Raphson law in ANSYS. The internal force of compound structural system under frequent earthquake would be compared with the results calculated by the earthquake response spectrum law. The maximal relative store displacement would proceed to check up through the displacement limit in ’code for seismic design of buildings’ . Thereby the seismic resistant capality of compound structural system will be determined.更多还原