四面受火状态下木-H型钢-混凝土方截面组合柱温度场数值模拟

Numerical Simulation of Temperature Field in Wood-H Shaped Steel-Concrete Composite Column with Square Cross Section after Exposure to Four-Side Fire

目的 提出一种新型的木-H型钢-混凝土方截面组合柱,研究火灾下组合柱的温度场分布规律。方法 应用ABAQUS有限元分析软件建立组合柱的热传递模型,采取ISO-834标准升温曲线进行升温,研究混凝土厚度、再生粗骨料取代率和螺栓对组合柱内木材温度场和炭化的影响。结果 木材的温度场呈双向对称分布;混凝土厚度每增加10 mm,螺栓孔处木材的炭化深度平均减少25.43%,初始炭化时间平均延后22.82%;再生粗骨料取代率每增加20%,木材炭化深度平均减小6.34%,初始炭化时间平均延后5.60%;螺栓的存在会加剧木材的炭化,螺栓孔处的木材的炭化深度多出57.13%。结论 在火灾作用下,组合柱内部的木材炭化后仍有较大的有效剩余截面;H型钢腹板有木材包裹,强度劣化速度缓慢;木-H型钢-混凝土组合柱的抗火性能良好。

A new type of wood-H shaped steel-concrete composite column with square cross section was proposed to study the temperature field distribution law of composite column under fire.ABAQUS finite element software was used to establish the heat transfer model of the composite column,and ISO-834 standard fire curve was adopted to warm up the column,and the influence of concrete thickness,recycled coarse aggregate substitution rate and bolts on the temperature field and charring of wood in the composite column was investigated.The temperature field of the wood was distributed bi-directionally and symmetrically;for every 10mm increase in concrete thickness,the charring depth of the wood at the bolt holes decreased by 25.43% on average,and the initial charring time was delayed by 22.82% on average;for every 20% increase in recycled coarse aggregate substitution rate,the charring depth of the wood decreased by an average of 6.34%,and the initial charring time was delayed by an average of 5.60%;the presence of bolts exacerbated the charring of the wood,and the charring depth of the wood at the bolt holes was 57.13% more.Under fire,there is still a large effective residual cross-section after the charring of the wood inside the composite column.The H shaped steel is wrapped with wood,and the strength deterioration is slow.The fire resistance performance of wood-H shaped steel-concrete composite columns is good.