钢板混凝土简支梁抗剪承载模式及承载力分析

Study on shear resisting pattern and strength of simply supported steel-concrete-steel sandwich beams

以8根钢板混凝土组合简支梁的弯剪试验为基础,对构件的受剪破坏过程和破坏模式进行分析,基于试验中观测到的剪切破坏形态,以及测得的钢板受拉应变发展情况,建立钢板混凝土组合简支梁的抗剪承载力计算模型。模型根据构件临界开裂荷载与临界开裂后的抗剪承载力的相对大小,将剪切破坏模式分为混凝土开裂引起的脆性破坏和下部钢板拉剪屈服引起的延性破坏两类,模型计算承载力与试验结果相符。分别对ACI 349规程(针对钢筋混凝土结构)和JEAC 4618—2009规程(针对钢板混凝土结构)中建议的构件抗剪承载力的计算方法进行分析,通过与试验实测承载力的对比,得出各规程用于钢板混凝土构件时的适用程度和安全裕度。分析表明,导致计算值偏差的根本原因在于钢筋混凝土构件与钢板混凝土构件在破坏模式上的区别。

Based on the experimental study of eight specimens,the shear failure process and failure patterns of simply supported steel-concrete-steel（ SCS） sandwich beams were analyzed. According to the observed failure modes and tested tensile strain of the bottom steel plate,an analytical method was developed to predict the ultimate shear resistance of SCS beams. Shear failure modes were classified into two types,namely,brittle failure resulting from concrete critical diagonal cracking,and ductile failure caused by shear-tension yielding of the bottom steel plate. The proposed method gives satisfactory predictions compared with the test results. The shear capacity calculation method proposed by the ACI 349 code and JEAC 4618—2009 code was studied,and the applicability and conservation of these two codes were discussed.The reason of the calculation deviation of the two codes is supposed to be the essential difference in failure patterns between reinforced concrete（ RC） members and steel-concrete-steel（ SCS） composite members.