外挂ALC墙板-钢框架及连接节点受力性能研究

Study on Mechanical Behavior of Steel Frame with ALC Wall Panels and Its Connections

对外挂式ALC条形墙板与传统钩头螺栓节点的破坏特征及受力机理进行了试验研究.针对上述连接方式不足,提出了在ALC墙板内部节点周围布置加密钢筋网的抗震措施,对加强墙板节点受力性能进行了研究.为此设计了不开窗洞墙板钢框架、开窗洞墙板钢框架、节点加强墙板钢框架、节点加强开窗洞墙板钢框架四个试件进行低周反复加载试验,利用有限元软件ABAQUS建立了实体模型,研究结果表明:洞口是墙体的薄弱环节,洞口周围墙体最容易先出现破坏,窗墙比对框架整体的滞回性能影响很小.对于采用传统钩头螺栓连接的试件,当层间位移角在1/250 rad以内,墙板之间的灌浆勾缝处出现竖向裂缝,连接节点周围出现少量的水平裂缝,基本可以满足结构的正常使用要求.当层间位移角达到1/75 rad,墙板连接节点处裂缝斜向发展,周围混凝土逐步挤压破碎,墙板不能适应主体框架的变形,罕遇地震下有掉落、坍塌的风险.钢筋加密网是一种可靠的抗震措施,对墙板受力贡献较大,可以有效延缓墙板开裂时的层间位移,减轻墙板的损伤程度,使墙板满足钢结构较大的层间变形的需求,满足规范中对非结构构件层次的抗震设防要求.

Quasi-static experiments were conducted to study the failure mode and bearing mechanism of exter⁃nal ALC wall panel and traditional hook blot connections.In view of the insufficiency of the above connections,the seismic detail measures of placing the densified steel mesh around the internal connections in ALC wall panels were proposed,and the mechanical performance of the connections is studied.For this purpose,wall panels with and with⁃out an opening and the panel reinforced with steel mesh were designed,and low-cycle loading tests were conducted on these specimens.The finite element software ABAQUS was used to conduct numerical simulation.The results showed that openings were the weak components of ALC panels and destroyed firstly,but the size of openings has little effect on steel frame’s seismic performance.For the specimens with traditional hook blot connections,when the story drift ratio was less than 1/250 rad,there were vertical cracks on filling materials between ALC panels and tiny horizontal cracks around blot connections,which satisfies the requirements of the serviceability limit state.When the story drift ratio reached 1/75 rad,the cracks around connections develop obliquely,and the surrounding concrete was gradually compressed and crushed,so the panels were less likely to adapt to the deformation of main structures with the risk of dropping down and collapse under rare earthquake.However,this measure for the specimens embedded with reinforcing steel mesh in the panel was effective and reasonable,which provide enough force support for the pan⁃els,and can effectively delay the crack displacement of panels,satisfy the needs of relatively large structural lateral deformation and satisfied the requirement for seismic resistance of non-structure components in codes.