【作者】 黄智光；

【导师】 何保康； 苏明周；

【作者基本信息】 西安建筑科技大学 ， 结构工程， 2011， 博士

【摘要】 低层冷弯薄壁型钢房屋作为一种新型住宅结构体系在我国已逐渐开始应用,但关于该房屋整体的抗震性能研究资料较少。为研究低层冷弯薄壁型钢房屋的抗震性能,进行了十片1∶1冷弯薄壁型钢墙体试件水平低周反复加载试验、三组自攻螺钉连接抗剪性能试验和一个三层冷弯薄壁型钢房屋足尺模型振动台试验,分别得到了不同构造墙体的屈服荷载、最大荷载、破坏荷载、耗能系数和延性系数等性能指标,不同板材自攻螺钉连接的抗剪承载力以及房屋结构在水平地震作用下的动力特性、地震反应、破坏机理、抗震性能等。在试验研究的基础上,应用ANSYS程序建立了墙体非线性有限元分析模型,进行了一定参数分析;采用SAP2000程序中多线段塑性Pivot连接单元的滞回规则,进行了墙体恢复力模型及非线性简化分析方法研究;应用SAP2000程序建立了三层房屋结构动力简化分析模型,进行了线性和非线性地震反应分析。墙体试验和非线性有限元分析结果表明:斜撑对提高单柱墙体的抗剪承载力起一定作用,但对双柱墙体的作用很小;按《低层冷弯薄壁型钢房屋建筑技术规程》规定计算开洞墙体的抗剪承载力偏于安全;双柱墙体比单柱墙体的抗剪承载力显著提高;试验时各试件立柱的应变反应普遍较大、横撑次之、斜撑最小;墙面板在接缝处相对滑移较大,工程中应尽量减少墙板接缝,避免横向通缝;有限元模型的墙体骨架曲线与试验曲线的初始刚度和曲线吻合较好;两面覆石膏板双柱墙体比单柱墙体的屈服荷载提高;两面覆石膏板墙体与覆OSB板+石膏板墙体相比,前者抗剪刚度、屈服荷载和最大荷载明显减小。墙体恢复力模型及非线性简化分析结果表明:墙体的骨架曲线可采用退化四线型模型模拟;双柱墙体Pivot模型参数可取α=10、β=0.1,单柱墙体可取α=10、β=0.15;非线性简化分析得到的滞回曲线的外包络线与试验基本一致,耗能能力相当;简化方法能较好地模拟墙体的强度、刚度退化和捏缩效应。三层房屋模型振动台试验和动力简化分析结果表明:结构在振动过程中表现为局部破坏,墙体骨架基本完好;9度抗震设防时,多遇地震下结构最大弹性层间侧移角为1/934,罕遇地震下结构最大弹塑性层间侧移角为1/52,满足抗震规范关于抗震变形验算的相关规定;房屋体系的抗侧能力主要来源于墙面板的蒙皮作用和抗拔件的抗倾覆作用;经分析和评估,房屋达到了高烈度地区的抗震设防要求;房屋结构简化计算模型的第1、2阶振型与试验观测一致,频率分别相差11%和2%;简化计算方法能较好地应用于冷弯薄壁型钢房屋的弹性和弹塑性地震反应分析。更多还原

【Abstract】 As a new structural system, low-rise cold-formed thin-wall steel residential buildings have been used in Chinese gradually. However, the research on seismic behaviors of this structural system is seldom involved. To study the seismic behaviors of low-rise cold-formed thin-wall steel residential buildings under horizontal earthquake action, three tests including full scale model test on 10 pieces of wall panels under cyclic horizontal load, self-drilling screw connection test on three groups of specimens and shaking table test on a full scale three-story residential building model have been carried out in this paper. The following test results were obtained respectively: The shearing performance indexes of wall panels such as yield load, maximum load, failure load, energy dissipation coefficient and ductility factor; The shear resistance of self-drilling connection specimens; Dynamic properties, seismic responses, damage features and seismic behaviors etc. of three-story cold-formed thin-wall steel residential building.Based on experimental study, the following theory analysis were developed: The nonlinear finite analysis model was established and a detailed parameter analysis was carried out by ANSYS program; Restoring force model and nonlinear simplified analysis method of cold-formed steel wall panels were studied by using the hysteresis rules of multi-linear plastic Pivot element in SAP2000 program; The simplified dynamic analysis model of cold-formed thin-wall residential building was established, linear and nonlinear seismic response analysis was carried by SAP2000 program. Based on the test results and finite element analysis on cold-formed wall panels, the following conclusions could be suggested: The diagonal bracings are helpful to improve the shear resistance of single-column wall panels while nearly useless to double-column wall panels; The calculation method of the shear resistance of wall panels with openings suggested by Technical Specification for Low-Rise Cold-formed Thin-Wall Steel Buildings is conservative; The shear resistance of double-column wall panels are obviously higher than that of single-column ones; The strain response is largest for columns, less for the transverse bracings and least for the diagonal bracings; As the interface slip between the upper and lower wallboards is obvious, the seams between wallboards should be as little as possible and the transverse continuous seams should be avoided in practice; The initial stiffness of wall panels obtained from test results agree well with those from finite element analysis; As far as wall panels with plasterboards on both sides are concerned, the yield loads of double-column wall panels are higher than those of single-column ones; The initial stiffness, yield load and maximum load of wall panels with plasterboards on both sides are obviously lower than those with OSB board plus plasterboard on both sides.Restoring force model and nonlinear simplified analysis results indicate that the skeleton curves of wall panels can be modeled by the degenerated four-linearity model; the Pivot model parametersαandβcan be taken as 10 and 0.1 for double-column wall panels, while 10 and 0.15 for single-column ones, respectively; the envelope of hysteresis curves and capacity of dissipating energy of wall panels obtained from nonlinear simplified analysis are similar to those from test; the strength degeneration, stiffness degeneration and rheostriction phenomena of wall panels can be well modeled by simplified analysis method.Shaking table test and the simplified dynamic analysis results indicate that the residential building structure is mainly suffered local damage during test, while the cold-formed steel frame is almost undamaged; When seismic fortification intensity is degree 9, the maximum elastic story drift angle of structure under frequent earthquake and that of elastic-plasticity under rare earthquake are 1/934 and 1/52 respectively, which met the demand of Chinese Code for Seismic Design of Buildings; The skin action of wall panels and action to resist overturning moment of hold downs are very important to the lateral resisting of the building structure; Preliminary evaluation shows that the structure safety is guaranteed; The first two modal of residential building obtained from analysis is identical to those from test, and the discrepancy of the fundamental and secondary frequency are 11% and 2% respectively; The simplified dynamic analysis method can be applied to elastic and elasto-plastic seismic response analysis of cold-formed thin-wall residential building.更多还原