Advanced seismic force resisting systems for cold-formed steel framed building structures

冷弯薄壁型钢框架结构是一种复杂的结构体系，在地震作用下，其寿命周期内承受着最苛刻的要求。AISI S400中描述的当前CFS横向系统预期用于1至3层建筑物。鉴于市中心的人口不断增加，有必要发展更高和更大的建筑物，以更好地优化我们城市的土地利用;即CFS框架中高层建筑，高度可达8层。在设计水平地震中，对此类建筑物的力和变形要求需要开发一种横向框架系统，以提高现有CFS系统的能力。麦吉尔大学的初步研究已经证明了由CFS构件和面板构成的中心护套框架系统的潜力，其承载的剪切载荷远远超过AISI S400设计的可能性，并具有显著改善的延性。 5年研究计划的目标是：（i）开发用于中高层建筑施工的CFS中心护套剪力墙系统，（ii）扩展NBCC中列出的CFS横向抗震系统（R值和高度限制），以及（iii）提供涵盖这些系统的设计和施工的指南，以纳入AISI设计标准。 方法学：通过实验室测试确定框架/护套连接的响应、框架作用、弦杆对组合荷载的响应以及非结构部件对抗剪性和刚度的影响。完成基于有限元的剪力墙及其弦杆配置的参数研究，以扩大表征信息的数据库。建立了中心护套墙的分析设计方法。使用OpenSees模型对建筑物进行动态分析，该模型能够代表剪力墙的高强度和延性、横隔板的灵活性、非结构构件和承重墙的附加强度和刚度以及弦杆的非线性响应，以验证分析设计方法并量化所有墙体构件的贡献。通过对不同位置的建筑物模型和适用的比例地面运动套件进行动态分析，制定倾覆/上抬设计方法，并提出地震R值。使用脆弱性曲线来量化失败的概率。HQP：1名博士，4名硕士，5名大学生和实验室技术人员。 这一创新性的研究将推动CFS框架中高层建筑抗震设计学科的发展。规范和标准将更新CFS框架结构的抗震设计和分析。CFS框架结构在地震事件中倒塌的可能性将得到改善，建筑物业主和居住者的安全也将得到改善。加拿大以外的学术研究项目将获得这些研究成果，这些研究成果可以纳入全球可比的设计指南。

Cold-formed steel (CFS) framed buildings are complex systems that under earthquake ground motion excitation experience the most severe demands of their life cycle. The current CFS lateral systems described in AISI S400 are intended for use in 1 to 3 storey buildings. Given the continually increasing population in urban centres, there exists a need to develop taller & larger buildings to better optimize land use in our cities; that is, CFS framed mid-rise buildings extending up to 8 storeys in height. The force and deformation demands placed on such buildings in a design level earthquake require the development of a lateral framing system that improves upon the capability of existing CFS systems. Preliminary studies at McGill have demonstrated the potential of a centre-sheathed framing system constructed of CFS members & panels to carry shear loads far in excess of what is possible using designs from AISI S400, with substantially improved ductility.   The objectives of the 5 year research program are: (i) Develop a CFS centre-sheathed shear wall system for use in mid-rise building construction, (ii) Expand on the CFS lateral seismic systems (R-values & height limits) listed in the NBCC, and (iii) Provide guidelines covering the design & construction of these systems for inclusion in the AISI design standards.   Methodology: Characterize through laboratory testing the response of framing / sheathing connections, frame action, response of chord members to combined loading, and the impact of non-structural components on shear resistance and stiffness. Complete a FE based parametric study of the shear walls and their chord stud configurations to broaden the database of characterization information. Establish an analytical design method for the centre-sheathed walls. Institute dynamic analyses of buildings using OpenSees models, capable of representing the high strength & ductility of the shear walls, the flexibility of the diaphragms, the added strength & stiffness of the non-structural components & bearing walls & the non-linear response of the chord studs, to verify the analytical design approach and to quantify the contribution of all wall components. Develop a design method for overturning / uplift and propose seismic R-values through dynamic analyses of building models for various locations and applicable suites of scaled ground motions. Use fragility curves to quantify the probability of failure. HQP: 1 PhD, 4 Master's, 5 Ugrad students & lab technicians.   This innovative research will advance the discipline of CFS framed mid-rise building seismic design. Codes & standards will be updated for the seismic design and analysis of CFS framed structures. The likelihood of collapse of CFS framed structures during a seismic event will be improved, as will the safety of building owners & occupants. Academic research programs beyond Canada will have access to these research findings that can be incorporated in comparable design guides worldwide.