方钢管混凝土组合异形柱框架抗震性能试验与有限元研究

发布时间：2018-06-06 18:25

本文选题：方钢管混凝土组合异形柱 + 拟静力试验　；参考：《天津大学》2014年硕士论文

【摘要】：近年来方钢管混凝土组合异形柱框架结构逐渐在多层住宅中推广应用,为了研究其抗震性能,本文对三榀两层单跨的方钢管混凝土组合异形柱-H型钢梁框架在恒定轴压力和往复水平力作用下的力学性能进行了试验研究,主要考察不同的轴压比和梁柱线刚度比对其力学性能的影响。由试验结果发现,方钢管混凝土组合异形柱-H型钢梁框架具有良好的耗能能力和延性,强度和刚度退化不明显,具有良好的抗震性能。轴压比的增加会降低试件的延性和耗能能力,但能增加试件的承载力;梁柱刚度比的增加会增大试件的延性和耗能能力,减小承载力;而框架的刚度退化受梁柱线刚度比作用不明显,会随着轴压比的增加略微加剧。建立了两种有限元模型,分别是有接触单元和无接触单元的有限元模型,并将两种有限元模型与试验结果作对比。经过对比发现,两种有限元模型的应力变化基本同步,服从梁端首先形成塑性铰,随后柱脚屈服的破坏模式。有接触单元的有限元模型比无接触单元的有限元模型计算更精确,更符合试验规律。后使用无接触单元建立了与试验试件完全相同的有限元模型,将其计算结果与试验结果作对比,发现无接触单元的有限元模型计算结果总体拟合较好,其计算所得承载力和延性都较试验结果略偏高。但有接触单元的计算所需时间是无接触单元的五倍,应视所需计算精度和计算时间选取合适的计算模型。使用经试验验证的有限元模型对SCFST框架进行参数化分析,考察其在不同轴压比作用下的力学性能,发现所有框架都有很好的耗能能力和延性,但当轴压比达到0.6时,柱脚会先于梁端屈服。随轴压比的增加框架的耗能能力、延性和承载力都会降低。通过改变梁尺寸和跨度的方法改变框架的梁柱线刚度比,对比6个不同梁柱线刚度比的SCFST框架,发现框架的承载力和延性随着线刚度比的增加而增大,并且加大梁高是提高框架承载力更有效途径,减小跨度是加大试件延性更有效的方法。通过五个不同加劲肋间距的框架在滞回荷载下的分析发现,加劲肋间距较大的试件,连接板在位移较大会大面积屈服,而加劲肋间距较密的构件,会造成连接板受力不均匀,在节点处应力较大,因此从分析结果可以认为加劲肋间距与连接板宽度之比为1.75时连接板受力情况最好。
[Abstract]:In recent years, concrete-filled square steel tube (CFST) composite special-shaped column frame structure has been popularized and applied in multi-story residential buildings, in order to study its seismic performance, In this paper, the mechanical properties of three concrete-filled square steel tubular composite columns with two stories and one span under constant axial pressure and reciprocating horizontal force are studied experimentally. The effects of axial compression ratio and Liang Zhu line stiffness ratio on mechanical properties were investigated. It is found from the test results that the steel beam frame with concrete-filled square steel tubular composite special-shaped column has good energy dissipation capacity and ductility, strength and stiffness degradation is not obvious, and has good seismic performance. The increase of axial compression ratio will decrease the ductility and energy dissipation capacity of the specimen, but increase the bearing capacity of the specimen, increase the Liang Zhu stiffness ratio will increase the ductility and energy dissipation capacity of the specimen, and reduce the bearing capacity. However, the stiffness degradation of the frame is not obvious by the Liang Zhu line stiffness ratio, and will be slightly aggravated with the increase of axial compression ratio. Two kinds of finite element models, one with contact element and the other without contact element, are established, and the two finite element models are compared with the experimental results. By comparison, it is found that the stress changes of the two finite element models are basically synchronous, and the failure mode of plastic hinge is first formed from the end of the beam and then the column foot yields. The finite element model with contact element is more accurate than the finite element model without contact element. The finite element model which is exactly the same as the test specimen is established by using the contactless element, and the calculated results are compared with the experimental results. It is found that the finite element model of the contactless element fits well in the whole. The calculated bearing capacity and ductility are slightly higher than the experimental results. However, the calculation time of the contact element is five times that of the non-contact element, and the appropriate calculation model should be selected according to the required calculation accuracy and calculation time. The finite element model is used to parameterize the SCFST frame. The mechanical properties of SCFST frame under different axial compression ratios are investigated. It is found that all the frames have good energy dissipation capacity and ductility, but when the axial compression ratio reaches 0.6, The foot of the column will yield before the end of the beam. With the increase of axial compression ratio, the energy dissipation capacity, ductility and bearing capacity of the frame will decrease. By changing the beam size and span, the Liang Zhu linear stiffness ratio of the frame is changed, and six different Liang Zhu linear stiffness ratios are compared. It is found that the bearing capacity and ductility of the frame increase with the increase of the linear stiffness ratio. Increasing the beam height is a more effective way to increase the bearing capacity of the frame, and reducing the span is a more effective way to increase the ductility of the specimens. Through the analysis of five frames with different stiffening rib spacing under hysteretic load, it is found that the specimens with larger stiffening rib spacing will yield in a large area when the displacement is large, while the members with more stiffened rib spacing will cause the joint plate to be subjected to uneven forces. The stress at the joint is large, so it is considered that when the ratio of stiffened rib spacing to the width of the connecting plate is 1.75, the stress of the connection plate is the best.
【学位授予单位】：天津大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TU398.9;TU352.11

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