Collaborative Research: Fire Engineering Guidelines for the Design of Steel Beam-Columns

结构防火安全是高层建筑设计的主要考虑因素之一，在高层建筑中，钢材往往是首选材料。高层建筑中最常见的结构构件之一是由梁柱组成的抗弯框架构件。本项目的目标是开发简单的工具和设计指南，用于预测钢梁-柱结构系统在真实火灾、荷载、破坏和几何条件下的需求和能力。为实现上述目标，密歇根州立大学(MSU)和普林斯顿大学(PU)在以下五个方面开展了一项合作研究：(1)真实火灾和荷载情况下的试验研究；(2)基于火灾-传热-结构相互作用耦合模型的有限元参数研究；(3)预测具有温度梯度的梁柱体系的性能(即需求)；(4)评估框架中梁柱(特别是周长柱)的性能；以及(5)制定梁柱耐火性能评估准则，并将信息传递给规范和标准。任务(1)中的火灾试验数据将用于验证和校准任务(2)中的有限元模型，这将成为开发简化设计工具和指南的基础。本研究的优点在于为涉及梁柱相互作用的高度复杂的问题开发设计方法。拟议的火灾试验研究是独一无二的，因为它将导致(首次)在设计火灾、真实荷载、破坏和约束情景下开发梁柱的试验数据。所提出的数值研究包括利用基于理论传热学和力学原理的热/应变耦合平衡分析来跟踪梁柱的高度复杂的行为。因此，本文的研究对梁柱从火灾前到倒塌阶段整个加载范围内的火灾行为有了基本的认识。简化的公式和相关的设计准则将有助于将耐火设计融入整体结构设计，并将导致既有基础设施中钢梁柱的合理和经济的防火安全设计。因此，拟议的梁柱研究将成为制定设计指南的基础，以提供更好的消防安全，并有助于美国规范和标准的制定。PIS制定了向实习工程师传播这项工作的计划，他们为两名博士生和三名本科生在结构消防安全领域积累了丰富的研究经验。其中一名PIS是一名妇女，将大力招收妇女和少数族裔学生。

Structural fire safety is one of the primary considerations in the design of high-rise buildings, where steel is often the material of choice. One of the most common types of structural members in high rise buildings is the moment-resisting frame (MRF) members, which consist of beam-columns. The objective of this project is to develop simple tools and design guidelines for predicting the demands and capacity of steel beam-column structural systems under realistic fire, loading, failure, and geometric conditions. To achieve the above objectives, a collaborative research between Michigan State University (MSU) and Princeton University (PU) involving full-scale fire experiments and numerical studies is proposed under the following five tasks: (1) experimental investigation under real fire and loading scenarios; (2) finite element parametric study using coupled fire-heat transfer-structural interaction model; (3) predict the system behavior (i.e., demands) of beam-columns with thermal gradients; (4) evaluate the behavior of beam-columns (specifically perimeter columns) in frames; and (5) develop guidelines for evaluating fire resistance of beam-columns and transfer the information to codes and standards. The data from fire experiments in Task (1) will be used to validate and calibrate the finite element models in Task (2), which in turn will form the basis for developing simplified design tools and guidelines.The intellectual merit of this research lies in developing design approaches for the highly complex problem involving fire-structure interaction of beam-columns. The proposed fire experiments studies are unique since it will lead to development of test data (for the first time) for beam columns under design fires, realistic loading, failure, and restraint scenarios. The proposed numerical studies involve tracing the highly complex behavior of a beam-column using coupled heat transfer/strain equilibrium analysis based on theoretical heat transfer and mechanics principles. Thus, the research proposed here lead to fundamental understanding on the fire behavior of beam-columns in the entire range of loading from pre-fire stage to collapse stages. The simplified equations and associated design guidelines will facilitate integration of fire resistance design into overall structural design and will lead to cost-effective and rational fire safety design of steel beam-columns in built infrastructure. Thus, the proposed research on beam-columns will form the basis for developing design guidelines to provide improved fire safety and contribute to the development of US codes and standards. The PIs have developed programs to disseminate the work to the practicing engineer, and they have developed a rich research experience for two PhD and three undergraduate students in structural fire safety area. One of the PIs is a woman and strong efforts will be made to recruit women and minority students.