型钢混凝土梁弯扭性能试验研究

EXPERIMENT STUDY ON FLEXURAL AND TORSION PROPERTIES OF STEEL REINFORCED CONCRETE BEAMS

为研究型钢混凝土梁在弯扭作用下的受力性能,对12根型钢混凝土梁和1根钢筋混凝土梁进行单调加载试验,研究弯扭作用下梁的破坏形态、扭矩-扭率曲线,并进行损伤演变分析。研究结果表明:弯扭作用下试件均经历弹性阶段、弹塑性阶段和破坏阶段。对于配实腹式工字钢的型钢混凝土梁,扭弯比越小,裂缝出现得越早,配箍率对其开裂扭矩基本无影响。空腹式型钢混凝土梁发生弯型破坏和扭型破坏两种破坏形态。试件开裂前,弯扭作用下试件的抗扭能力不仅取决于混凝土抗拉强度,型钢的抗扭刚度也参与贡献。试件损伤也呈现三阶段特征,钢筋混凝土梁比型钢混凝土梁损伤程度更大,混凝土强度对试件后期的损伤影响很小。工字钢规格越大,对周围混凝土约束作用越小,越不利于受扭。

In order to study the mechanic properties of steel reinforced concrete beams under flexural-torsional condition,the monotonic loading tests of 12 steel reinforced concrete beams and 1 reinforced concrete beam were conducted.The failure patterns and torque-torsion ratio curves were studied and damage evolution was analyzed under bending and torsion.The results showed that the entire process of load-bearing in all specimens under bending and torsion could be divided into three stages which were elastic,elasto-plastic and failure stages.The smaller torsionbending ratio were,the earlier the cracks appeared in the solid-web steel reinforced concrete beams.Stirrup ratio had no significant effect on the increase of cracking torque.The failure patterns of angle steel truss reinforced concrete beams had two types:failure with flexural feature and failure with torsional feature.Before cracking,the torsional resistance performance of the specimens under bending and torsion depended not only on the tensile strength of the concrete,but also on the torsional rigidity of the steel.The damage degree of specimens also presented three stage features,and the damage degree of reinforced concrete beams was larger than that of steel reinforced concrete beams.The influence of concrete strength on the later damage of the specimen was very small.With the increase of theΙ-steel model,the constraint on the surrounding concrete became smaller and more unfavorable to torsion.