圆钢管自密实混凝土纯弯力学性能

基于合理的钢材和核心混凝土拉压本构模型,利用截面分层法对钢管混凝土纯弯构件弯矩-曲率进行全过程分析,建立了钢管混凝土实用组合抗弯刚度、极限抗弯承载力等计算式和钢管混凝土组合梁单元弯矩-曲率全曲线实用计算方法,通过3根钢管自密实混凝土和1根钢管普通混凝土受弯构件的试验研究,考察了混凝土强度和含钢率对构件纯弯性能的影响。试验结果表明,受弯构件受压区钢管对混凝土产生约束套箍作用,受拉区钢管处于双向受拉应力状态,提高混凝土强度对提高极限弯矩作用不明显,而增大含钢率对提高极限弯矩作用较明显,并且与分层法相比,组合单元法在保证精度的前提下,减少了截面分层,提高了程序的计算速度。

Pure Bending Properties of Self-Compacting Concrete Filled Circular Steel Tube

Based on appropriate numerical constitutive model of concrete filled steel tube,layered method was adopted to calculate the complete moment-curvature curves of concrete filled circular steel tube(CFST) subjected to pure bending,the practical composite flexural stiffness,practical flexural capacity and practical moment-curvature relationships of composite element for CFST beams were presented,the tests of three self-compacting concrete filled circular steel tubes and one normal concrete filled circular steel tube subjected to pure bending were carried out,the influences of concrete strength and steel ratio on the pure bending properties of the specimens were discussed.Experimental result shows that the confinement effect between steel tube and concrete happens in compressive side,but the steel tube is in biaxial tensile stress conditions in tensile side,with the strength increase of concrete,the flexural capacities of the specimens are hardly influenced,but with steel ratio increase,the flexural capacities are enhanced significantly.2 tabs,11 figs,10 refs.