圆锥形中空夹层钢管混凝土轴压短柱受力机理分析

为了研究圆锥形中空夹层钢管混凝土轴压短柱的受力机理,通过有限元软件ABAQUS建立了该类构件的力学模型,并与已有试验数据进行对比,验证了模型的合理性。分析了典型构件的受力全过程荷载-应变关系曲线、钢管与混凝土之间的相互作用力、破坏模态和荷载分配; 同时分析了空心率、锥度、钢管径厚比和混凝土强度等参数对相互作用力的影响。结果表明:典型构件荷载-应变关系曲线可分为弹性段、弹塑性段、下降段和稳定段4个阶段; 构件破坏是由外钢管向外鼓曲所导致的,破坏截面约在0.8H(H为构件高度)柱高处; 锥度和空心率的改变对构件破坏截面位置影响较大,随着锥度和空心率的增大,破坏截面位置逐渐向柱顶靠近; 影响外钢管与混凝土之间相互作用力的主要因素有空心率、锥度、外钢管径厚比、外钢管屈服强度和混凝土强度; 影响内钢管与混凝土之间相互作用力的主要因素有空心率、锥度和外钢管屈服强度; 内钢管径厚比与内钢管屈服强度对混凝土与内、外钢管之间的相互作用力影响较小,可不作为主要参数进行分析。

Analysis on Mechanical Behavior of Tapered Concrete-filled Double Steel Tubular Short Columns Under Axial Compression

In order to study the mechanical behavior of tapered concrete-filled double steel tubular(CFDST)short columns under axial compression, the mechanical model was established by the ABAQUS software, and the results were compared with the existing experimental data to verify the rationality of the model. The load-displacement curve, interaction stress between steel tubes and concrete, failure modes and load distribution of typical member were investigated respectively. The hollow ratio, tapered angle, ratio of diameter and thickness of steel tube and concrete strength to the influence of interaction stress between steel tubes and concrete were also analyzed. The result indicates that the load-displacement curve of tapered CFDST short column is divided into elastic stage, elastic-plastic stage, descending stage and maintenance stage.The failure of the member is caused by the outward bending of the outer steel tube, and the fracture cross section is at the height of 0.8H(H is the height of member). The changes of tapered angle and hollow section ratio have a great influence on the position of failure cross section, with the increase of tapered angle and hollow section ratio, the position of failure cross section is closer to the top of the column. The main factors affect the interaction stress between outer steel tube and concrete are hollow section ratio, tapered angle, ratio of diameter and thickness of outer steel tube, outer steel tube yield strength and concrete strength. The main factors affect the compressive stress between inner steel tube and concrete are hollow section ratio, tapered angle and outer steel tube yield strength. The ratio of diameter and thickness of inner steel tube and yield strength of inner steel tube have little effect on the compressive stress between steel tubes and concrete, and may not be analyzed as the main parameter.