耐火钢组合梁与钢管混凝土柱相关问题研究

发布时间：2018-02-09 02:18

本文关键词： 耐火钢钢-混凝土组合梁普通钢抗火试验抗火性能耐火极限有限元方法承载力　出处：《浙江大学》2017年博士论文　论文类型：学位论文

【摘要】：20世纪90年代以来,国内外学者针对组合梁的抗火性能进行了大量的试验和理论研究,但钢材多为普通钢,也有学者对耐火钢构件和耐火钢-钢管混凝土柱的抗火性能进行了分析,而未曾有对耐火钢-混凝土组合梁抗火性能的研究。本文对耐火钢-混凝土组合梁的抗火性能进行研究分析,完成的主要工作和取得成果包括:在ISO-834标准升温条件下,对2个耐火钢-混凝土组合梁和1个普通钢-混凝土组合梁进行抗火试验。研究耐火钢-混凝土组合梁在火灾下的承载特征和防火涂料厚度对其抗火性能的影响,对比同等条件下采用相同强度等级普通钢的组合梁的抗火性能,考察耐火钢替换普通钢对钢-混凝土组合梁抗火性能的提高和改善程度。试验结果表明,可以取跨中挠度达到梁跨的1/30作为简支耐火钢-混凝土组合梁达到耐火极限状态的界限。一定的火灾和荷载等条件下,采用相同强度等级耐火钢的钢-混凝土组合梁比普通钢组合梁具有更好的抗火性能,可减小建筑物的防火涂层厚度。运用基于有限元软件ABAQUS建立的分析模型分别对采用防火涂料和防火板保护的耐火钢-混凝土组合梁标准升温下的抗火性能进行模拟,分析荷载比,防火保护层,材料强度,截面尺寸,混凝土楼板中纵向钢筋等因素对耐火钢-混凝土组合梁抗火性能的影响。结果表明:荷载比和防火保护层厚度是影响耐火钢-混凝土组合梁抗火性能最重要的两个因素。当荷载比为0.5～0.7时,使用耐火钢替换普通钢后组合梁的耐火极限提高35%～400%,可以减小防火涂料厚度30%左右。采用我国规范(CECS200:2006)中的方法计算耐火钢-混凝土组合梁的耐火极限,荷载比较小时偏保守。基于舞钢耐火钢Q345-FR钢板高温力学性能试验结果,采用有限元方法对耐火钢-混凝土组合梁的抗火性能进行高温稳态分析和瞬态分析,得到标准升温下耐火钢-混凝土组合梁截面抗弯极限承载力-时间曲线和一定荷载比下组合梁的耐火极限。考察混凝土板尺寸、钢梁截面尺寸、涂料厚度、荷载比等参数对高温下组合梁承载力和耐火极限的影响。提出耐火钢-混凝土组合梁高温下承载力和耐火极限计算公式,公式计算结果与有限元结果非常吻合。将有限元计算结果与规程CECS200:2006方法的计算结果进行对比分析,结果表明规程方法偏于保守,受火时间越长,保守程度越大。本文发现,将腹板和下翼缘的温度分开计算更为合理,并依此提出了建议。分析单侧受火的耐火钢-混凝土组合梁的抗火性能和承载力,对相关影响因素进行参数分析,结果表明各因素对单侧受火的耐火钢-混凝土组合梁抗火性能的影响和三面受火时类似。和三面受火的耐火钢-混凝土组合梁的抗火性能进行比较,一定条件下,单侧受火时组合梁的耐火极限比三面受火时提高1倍以上。耐火钢-混凝土组合梁的抗火性能是本文的最主要的研究内容,本文还对矩形钢管混凝土构件的性能进行了一些基础试验,并研究了宽厚比对钢管混凝土轴压短柱承载力退化的影响。具体内容包括:对四组钢管混凝土构件进行试验:混凝土与冷弯钢管的粘结力的推出试验;冷弯钢管混凝土柱宽厚比试验;钢管混凝土梁受弯试验;钢管混凝土长柱轴压承载力试验。研究冷弯矩形钢管与混凝土之间的粘结力,共同工作性能,矩形钢管混凝土短柱的承载力和延性以及矩形钢管混凝土长柱的轴压承载力和稳定性。在钢管混凝土短柱轴压试验的基础上,分析宽厚比对钢管混凝土轴压短柱屈曲后剩余承载力的影响。运用ABAQUS有限元软件计算不同宽厚比的矩形钢管混凝土轴压短柱屈曲后的剩余承载力。结果表明,宽厚比对钢管混凝土轴压短柱屈曲后的剩余承载力有较大影响,宽厚比为60ε时,矩形钢管混凝土短柱剩余承载力可能下降到极限承载力的0.65。因此本文建议,对于以轴压抵抗地震作用的钢管混凝土柱构件(例如作为支撑架弦杆的立柱),建议宽厚比限值更严格至50ε,同时控制套箍系数限值为1.5。
[Abstract]:Since 1990s, domestic and foreign scholars on experimental and theoretical researches on fire resistance of composite beams of steel, but for ordinary steel, scholars have carried out analysis on the fire resistance of refractory steel and refractory steel - concrete filled steel tubular column, and there has not been research on beam fire resistance of steel concrete composite refractory. The fire resistance of fire analysis of steel concrete composite beams, the main work and achievements include: the ISO-834 standard heating condition of 2 refractory steel concrete composite beams and 1 common steel-concrete composite beam fire resistance test. Influence of refractory steel concrete composite beams under fire load characteristics and fire retardant coating thickness on the fire resistance capability, the fire resistance of composite beams of the same strength grade of ordinary steel equal conditions, effects of refractory steel to replace ordinary steel The degree of improvement of the fire resistance of steel-concrete composite beams. The test results show that the boundary can take the deflection to Liang Kua 1/30 as simply supported steel concrete composite beams to refractory refractory limit state. The fire and load conditions, using the same strength grade refractory steel - concrete composite beam than ordinary steel composite beams have better fire resistance, fireproof coating thickness can be reduced. By the simulation of building fire resistance analysis model of finite element software ABAQUS to establish the refractory concrete steel used for respectively fireproof coating and fire protection plate composite beam under standard temperature based on the analysis of the load ratio, fire protection layer and the strength of the material, the section size and influence of the concrete slab longitudinal reinforcement of beam fire resistance of refractory steel - concrete composite. The result shows that the load ratio and thickness of fire protection There are two factors that influence the refractory steel - concrete composite beam fire resistance is the most important. When the load ratio is 0.5 ~ 0.7, to replace the ordinary steel using fire-resistant steel after the combination of the fire resistance of beam increases from 35% to 400%, can reduce the thickness of fireproof coating is about 30%. The Chinese standard (CECS200:2006) calculation of fire-resistant steel - fire resistance the concrete composite beam method, compared with hour load conservative. Wugang refractory steel Q345-FR steel at high temperature mechanical performance based on the experimental results, using the finite element method for steady state analysis and transient analysis of high temperature of fire resistance of refractory steel concrete composite beams, obtained under the standard temperature of refractory steel concrete beams flexural ultimate bearing the force time curve and load ratio of composite beams under fire resistance. The influences of concrete slab size, beam section size, coating thickness, load ratio and other parameters of high temperature composite beam bearing Impact force and fire resistance limit. Under the proposed calculation formula of bearing capacity and fire resistance of refractory steel concrete composite beams under high temperature, calculation results and finite element results. The calculation results of finite element analysis and CECS200:2006 method for comparative analysis of the results, the regulation method is conservative, the longer the time by fire conservative, the greater the degree. It is found that the web and flange temperature calculated separately is more reasonable, and puts forward some suggestions accordingly. By the analysis of unilateral refractory steel - concrete composite beam fire fire resistance and bearing capacity, the parameter analysis of the related factors, the results showed that all the factors affected by the refractory steel the fire on the unilateral effects of fire resistant property of concrete beams and the combination of the three face under fire. Similar and three sides of fire-resistant steel - fire fire resistance of concrete composite beams were compared, under certain conditions, the unilateral group under fire Improve the fire resistance of beam than the three face under fire when more than 1 times. The fire resistance of refractory steel - concrete composite beam is the main research contents, this paper also tests some basic properties of concrete filled rectangular steel tube members, and the effects of the ratio of width to thickness of degradation of bearing capacity of concrete filled steel tubular stub columns shaft pressure. The specific contents include: Test of concrete filled steel tubular members of four groups: the test launch of bond force of the concrete and the cold-formed steel tube; cold-formed steel pipe concrete column slenderness ratio of concrete filled steel tube Liang Shouwan test; test; concrete filled steel tubular long columns under axial compression bearing capacity test. Research on bond strength between cold-formed rectangular steel tube and concrete, working performance rectangular concrete filled steel tubular short columns, bearing capacity and ductility of concrete-filled rectangular steel tube columns and the axial bearing capacity and stability. Based on compression test of concrete filled steel tubular short column shaft On the analysis of ratio of width to thickness of CFST short column buckling residual bearing. Using ABAQUS finite element software to calculate different thickness of rectangular steel tube concrete axial ratio buckling column after the residual bearing capacity. The results showed that the ratio of width and thickness of concrete filled steel tubular short columns under axial compression flexion residual bearing capacity after the song has a great influence 60, width to thickness ratio epsilon, rectangular columns remaining 0.65. may drop to the ultimate bearing capacity of the proposal for pressure resistance of concrete filled steel tubular columns with axial earthquake components (such as column support chord), suggested that thickness ratio of more stringent limit to 50 epsilon, while the control set hoop coefficient limit is 1.5.

【学位授予单位】：浙江大学
【学位级别】：博士
【学位授予年份】：2017
【分类号】：TU398.9

【相似文献】