墙角火灾环境下钢构件温度分布及响应行为的实验研究

利用ISO9705标准火灾实验系统，模拟墙角火灾环境，以薄壁方管钢梁为研究对象，对钢构件在热、力耦合作用下的行为进行实验研究。对火灾的热释放速率与室内温度场，钢构件及其表面气体的温度、构件在火灾作用下的挠度进行测量，分析真实火灾下钢构件温升及温度分布的特点与火灾发展对构件挠度的影响。研究结果表明钢构件在长向上存在着很大的温差，而构件的挠度变化也并不对称，这说明以往研究中往往假设钢构件在长向上温度一致并不恰当，这种非均匀温度场对构件的行为有着重要影响，它使得构件高温区部分更易发生局部屈服而失效，在相同规模的

Experimental Study on Temperature Distribution and Response Behaviors of Steel Element under Corner Fire Conditions

By using ISO9705 Room/Corner Fire Test Rig, thin steel tubes were tested. The response behaviors of steel element under thermal-mechanical coupling effect in a simulated corner fire were studied. In the experiment, the heat release rate and temperature field of the fire, temperature and deflection of the steel element and the temperature of the gas close to steel surface were measured. Effects of the temperature elevation and distribution of the steel element under corner fire conditions along with the fire growth on the deflection were analyzed. Results show that there exists significant temperature difference along the longitude of the steel and an unsymmetrical deflection variation. These indicate that assumptions of the uniform temperature distribution along the longitude direction in previous studies were improper. Under this non-uniform temperature distribution, failure resulted from the local yield of the higher temperature zone of the element is more inclined to occur. Indeed, this non-uniform temperature distribution caused by the corner fire is more dangerous to the fire safety of steel elements than the even case under same fire size.