Fire Performance of HSS Steel Connections

背景：火灾会导致温度升高，从而对建筑构件和系统产生不利影响。钢连接是任何钢结构的重要组成部分。火灾观测证实，连接对结构构件的生存时间有相当大的影响，因为它们的作用是分配力。已知空心钢截面比厚钢截面吸收热能的速率更高，导致较早的屈服发生。在火灾中，受约束的钢梁会迅速升温，并对支撑柱造成横向推力。火山柱的断裂很可能是因为这种推力，而不一定是因为温度升高。目标：该研究旨在检查和评估在火灾条件下现有HSS-to-HSS扩展端板力矩连接的性能，并致力于引入一种能够吸收或重定向侧向推力的新连接。科学方法：通过中型和全尺寸实验，将评估当前和拟议的dhss - hss扩展端板弯矩连接在火灾条件下的性能。本文的研究重点是如何在火灾中利用悬链线的作用来提高约束钢梁的防火性能。采用ABAQUS有限元模型分析热工性能与结构性能的耦合效应。设计火灾（用于商业和工业类型的占用）以及标准时间-温度剖面将应用于使用卡尔顿大学新建的消防设施的连接。该研究有望促进对常用钢连接（非隔离连接）的火灾行为的理解，并提出一种先进的连接方式，可以提高火灾时的稳定性。研究结果将用于制定梁-柱连接的耐火设计方法。

Background: Fires can cause elevated temperature that can have adverse impact on the building elements andsystems. Steel connections are vital and essential components of any steel structure. Observations from firesconfirm that connections have considerable effect on the survival time of structural members due to their rolein distributing forces. Hollow Steel Sections HSS are known to absorb heat energy at higher rates than thicksteel sections, causing earlier yielding to occur. In a fire event, restrained steel beams can heat up quickly andcause lateral thrust on supporting columns. It is likely that columns fail because of this thrust, and notnecessarily because of the elevated temperatures.Objectives: The proposed research aims to examine and evaluate, under fire conditions, the performance ofexisting HSS-to-HSS extended end-plate moment connections and work towards introducing a new connectioncapable of absorbing or redirecting the lateral thrust.Scientific approach: Using medium- and full-scale experiments, the performance of current and proposedHSS-to-HSS extended end-plate moment connections in fire conditions will be assessed. The proposedresearch focuses on how to utilize the catenary action in fire in order to improve the fire performance ofrestrained steel beams. ABAQUS finite element model will be used to analyze the couple effect of thermal andstructural performance. Both design fires (for commercial and industrial type occupancies) as well as standardtime-temperature profiles will be applied to the connections using a newly constructed fire facility at CarletonUniversity's.The research is expected to advance the understanding of fire behaviour of the commonly used steelconnections (not isolated connections), and propose an advanced connection that can enhance the stability inthe event of fire. The results will be used to produce a fire resistance design method of beam-to-columnconnections.