基于ABAQUS的复合箍筋约束轻骨料混凝土柱偏压力学性能研究

Study on mechanical properties of lightweight aggregate concrete columns confined by composite stirrups under eccentric compression based on ABAQUS

为深入研究复合箍筋约束轻骨料混凝土柱偏心受压力学性能,首先采用有限元软件ABAQUS分别对14根箍筋约束柱建模,分析轻骨料混凝土强度、配箍形式、体积配箍率、偏心距对约束混凝土柱偏压力学性能的影响,然后探究试件破坏机理。研究结果表明:经复合箍筋约束后,相比普通配箍,试件的延性和承载力有显著提高,其中复合螺旋箍约束试件提高幅度最大,且螺旋箍主要在弹塑性、塑形阶段起作用,特别是在压区纵筋屈服后,复合箍筋对核心混凝土约束作用一直持续到加载结束。复合螺旋箍约束柱峰值荷载随着偏心距的增加而显著降低,但脆性有所改善;提高轻骨料混凝土强度,峰值荷载呈增大趋势,但是延性降低;峰值荷载随着体积配箍率的增大而提高。

In order to further study the eccentric compression performance of stirrup-constrained lightweight aggregate concrete columns, firstly, the finite element software ABAQUS was used to model 14 stirrupconfined columns respectively, and the strength, coupling form and volumetric coupling ratio of lightweight aggregate concrete were analyzed. The effect of eccentricity on the eccentric compression performance of confined concrete columns, and the failure mechanism of the specimen was also explored. The research results show that the composite stirrups restrain the ductility and bearing capacity of the lightweight aggregate concrete column significantly compared with the common stirrups, of which the composite spiral hoop restraint has the largest increase. Especially after the longitudinal reinforcement in the compression zone yields, and the restraint effect of composite stirrups on the core concrete continues until the end of loading. The ultimate bearing capacity of the composite spiral hoop restrained column decreases significantly with the increase of the eccentricity, whereas the ductility augment;it increases with augment of the concentrate strength of the lightweight aggregate concrete, whereas the ductility decreases;increases with the increase of the volume coupling rate.