斜拉桥斜拉索热分析温度场模拟方法研究

Study on Stayed Cable Thermal Analysis Temperature Field Simulation Methods of Cable-stayed Bridges

文章基于温度场计算理论,利用有限元软件ANSYS建立三塔斜拉桥斜拉索实体单元热分析模型,并采用随时间变化的热工参数(导热系数、比热、热膨胀系数、弹性模量)定义热分析模型,同时利用ISO834升温曲线对斜拉索施加热荷载,计算模拟出斜拉索随时间变化的温度场,得到斜拉索弹性模量的损伤程度。通过计算不同导热系数耐火层下斜拉索的温度场及力学性能,表明选用导热系数<1w/(m℃)的耐火层将显著降低斜拉索火灾下的温度,大大提高其抗火性能,为斜拉索的抗火计算和设计提供技术依据。

Based on the temperature field calculation theory, and through finite element software ANSYS,this article established the stayed cable solid-element thermal analysis model of three-tower cable-stayed bridge,and used the time-varying thermal parameters（thermal conductivity,specific heat, thermal expansion coefficient, elastic modulus amount）to define the thermal analysis model, while taking advantage of ISO834 heating curve to apply the heat load to stayed cables, it calculated and simulated the stayed cable temperature field varying with time, and obtained the damage degree of stayed cable elasticity modulus. Through calculating the stayed cable temperature field and mechanical proper-ties of different thermal conductivity under refractory layer, it showed that the refractory layer using the thermal conductivity 〈 1 w/（m℃）will significantly reduce the temperature of stayed cables under the tire,and greatly improve its fire resistance performance,thereby providing the technical basis for fire-resistant calculations and design of stayed cables.