W-LCFST柱抗震性能及弯矩-曲率关系研究

Study of Seismic Performance and Moment-Curvature Relationship of W-LCFST Columns

目的研究L形宽肢钢管混凝土组合柱(W-LCFST柱)的抗震性能及弯矩-曲率计算方法,为工程应用提供设计依据。方法应用ABAQUS有限元分析软件建立考虑混凝土塑性损伤和延性金属损伤的有限元模型,在验证模型合理准确的基础上,对比分析等肢截面、不等肢截面、轴压比及钢管厚度等参数对抗震性能的影响;基于W-LCFST柱的参数化分析结果和破坏现象,提出柱截面屈服、峰值和极限状态弯矩-曲率的简化计算方法。结果等肢W-LCFST柱截面高宽比从4.0增至5.0时,初始刚度和正向峰值承载力分别提高了16.9%和35.0%;X向截面高宽比从4.0增至5.0时,初始刚度和正向峰值承载力分别提高了15.3%和31.8%;Y向截面高宽比从4.0增至5.0时,初始刚度提高了9.4%,正向峰值承载力提高了18.0%;轴压比从0.2增至0.6时,正向峰值承载力和延性分别降低了13.8%和6.8%;钢板厚度从6 mm增至10 mm后,峰值承载力和延性分别提升了25.7%和4.9%。结论有限元模拟、试验和理论计算的结果吻合度较好,误差在10%以内,验证了弯矩-曲率计算方法的准确性;等肢截面高宽比增加,增大X向肢长和增加钢管厚度使柱的承载力、初始刚度和延性有明显提高。

In order to study the seismic performance of the wide-leg L-shaped CFST column(W-LCFST column).ABAQUS was used to establish the finite element model considering the plastic damage of concrete and ductile metal damage,on the basis of verifying the reasonableness and accuracy of the model,comparison and analysis the effect on seismic performance of parameters such as equal limb section,unequal limb section,axial compression ratio,steel thickness.The results showed that height-width ratio of W-LCFST column with equal limb from 4.0 to 5.0,the initial stiffness and peak positive load capacity increased by 16.9%and 35.0%respectively,The height to width ratio of X-direction increasing from 4.0 to 5.0,the initial stiffness and peak positive load capacity of column has increased by 15.3%and 31.8%.When the height to width ratio of Y-direction increased from 4.0 to 5.0,the initial stiffness and positive peak load capacity increased by 9.4%and 18.0%respectively.The load carrying capacity and ductility has decreased by 13.8%and 6.8%respectively with axial compression ratio from 0.2 to 0.6.Peak carrying capacity and ductility increased by 25.7%and 4.9%respectively after steel thickness from 6mm to 10 mm.The results of finite element simulation,experiment,and theoretical calculation are in good matching degree with an error of within 10%,verified the accuracy of the bending moment curvature calculation method.Increasing the equal limb section ratio,X-direction limb length and steel thickness improve the bearing capacity,initial stiffness and ductility of column.