Advancing the seismic performance of cold-formed steel framed building structures

提高冷弯型钢框架建筑结构的抗震性能

• 批准号: RGPIN-2014-06202
• 负责人: Rogers, Colin
• 金额: $ 2.04万
• 依托单位: McGill University
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2018
• 资助国家: 加拿大
• 起止时间: 2018-01-01 至 2019-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=663585
• 关键词: Advancing; seismic; performance; cold; formed

Ease of fabrication, high strength-to-weight ratio, dimensional accuracy, infinite recyclability & reusability, among other attributes, have led to the increase in construction of cold-formed steel (CFS) framed multi-storey residential and commercial buildings. CFS framed buildings are complex systems that under earthquake excitations experience the most severe demands of their life cycle. Improved design procedures will lead to a direct enhancement of life safety for building occupants & owners. New North American design standards to address the lateral loading demands on CFS structures are being developed. However, much of the existing research on which one can base the new lateral loading design standards is limited to tests of single-storey shear & braced walls under static or reversed cyclic displacement-based loading, approx. 20 dynamic tests of shear & braced walls, and a handful of CFS framed diaphragm tests. While informative, this existing research has not incorporated the influence of a building's overall response to ground motions, which is dependent on; the diaphragms, the interconnectivity of the roof & floor diaphragms with the vertical walls and the presence of non-structural components. To reach the next phase of innovative, efficient and resilient buildings engineers often find themselves modeling the full 3D structural system. Given the current state of knowledge of CFS buildings engineers are left in the situation where they must make gross simplifications in the building models for the floor & roof diaphragms, connections between the diaphragms & walls, along with other structural & non-structural components. Simplifications that lead to i) inefficiencies, because the influence of the diaphragm & diaphragm-to-wall interface is ignored; ii) inaccuracies because the forces transmitted by the diaphragm to the walls are approximated & simplified, and the forces that develop in the diaphragms themselves are not well understood; iii) incorrect period of vibration estimates because the ignored non-structural components (gypsum sheathed interior walls & clad exterior walls) often have equivalent stiffness to the structural CFS walls; and iv) over-design because the ignored non-structural components have similar shear resistance to the structural CFS walls. Taken together these lead to v) an incomplete understanding of the full 3D CFS seismic force resisting system. The long term objective of the research program is to develop proven seismic design methods for CFS framing systems The specific 5 year short term objectives of the proposed research are: i) provide characterization of typical floor diaphragm & wall force vs. deformation hysteretic response with & without non-structural components; ii) devise a numerical model, appropriate for building response evaluation under dynamic seismic loading, to investigate the influence of the main structural components in a building including the walls, the diaphragms (floors and roofs), the connections between walls, diaphragms & non-structural components; iii) carry out evaluations using this numerical model to identify & quantify building (diaphragm/wall) response to ground motions; iv) recommend guidelines as how to accurately address the influence of diaphragms & non-structural components in the practical engineering design of CFS framed structures; and v) include the recommended CFS seismic design procedures in the relevant design standards; AISI S400, CSA S136 & the National Building Code. Given that the design standards for CFS are intended for use throughout North America it is imperative that issues relevant to Canadian engineers be incorporated within the design documents; this requires the participation of Canadian universities in design standards development.

易于制造、高强度重量比、尺寸精度、无限可回收性和可重复使用性等属性，导致冷弯型钢 (CFS) 框架多层住宅和商业建筑的建设增加。 CFS 框架建筑是复杂的系统，在地震激励下会经历其生命周期中最严格的要求。改进的设计程序将直接提高建筑居住者和业主的生命安全。正在制定新的北美设计标准，以满足 CFS 结构的横向荷载需求。然而，新的横向荷载设计标准所依据的现有研究大多仅限于单层剪力墙和支撑墙在静态或反向循环位移荷载下的测试，大约。 20 项剪力墙和支撑墙动态测试，以及一些 CFS 框架隔膜测试。虽然信息丰富，但现有的研究并未纳入建筑物对地面运动的整体响应的影响，这取决于：隔板、屋顶和地板隔板与垂直墙的互连性以及非结构部件的存在。为了实现创新、高效和弹性建筑的下一阶段，工程师经常需要对完整的 3D 结构系统进行建模。鉴于 CFS 建筑工程师目前的知识水平，他们必须对地板和屋顶隔板、隔板和墙壁之间的连接以及其他结构和非结构部件的建筑模型进行总体简化。简化会导致 i) 效率低下，因为忽略了隔膜和隔膜与壁界面的影响； ii) 不准确，因为膜片传递到壁的力是近似和简化的，并且膜片本身产生的力还没有被很好地理解； iii) 振动周期估计不正确，因为被忽略的非结构构件（石膏护套内墙和包覆外墙）通常具有与结构 CFS 墙相当的刚度； iv) 过度设计，因为被忽略的非结构构件与结构性 CFS 墙具有相似的抗剪力。综上所述，导致 v) 对完整 3D CFS 抗震系统的不完全理解。该研究计划的长期目标是为 CFS 框架系统开发经过验证的抗震设计方法。拟议研究的具体 5 年短期目标是： i) 提供典型楼板隔板和墙体力与变形滞后响应的特征无非结构部件； ii) 设计一个适用于动态地震荷载下建筑物响应评估的数值模型，以研究建筑物中主要结构部件的影响，包括墙壁、隔板（地板和屋顶）、墙壁、隔板和非建筑物之间的连接结构部件； iii) 使用该数值模型进行评估，以识别和量化建筑物（隔膜/墙壁）对地面运动的响应； iv) 就如何在 CFS 框架结构的实际工程设计中准确解决隔膜和非结构部件的影响提出指南； v) 将推荐的 CFS 抗震设计程序纳入相关设计标准； AISI S400、CSA S136 和国家建筑规范。鉴于 CFS 的设计标准旨在在整个北美地区使用，因此必须将与加拿大工程师相关的问题纳入设计文件中；这需要加拿大大学参与设计标准的制定。