圆钢管相贯节点角焊缝受力特点及面内抗弯承载力计算理论

发布时间：2018-04-14 14:12

本文选题：圆钢管相贯节点 + 角焊缝应力　；参考：《南京工业大学》2015年硕士论文

【摘要】：相贯节点由于有构造简单、外表美观、节省钢材且易于维护等优点被广泛应用于建筑结构、杆塔结构及海洋平台结构。相贯角焊缝是影响节点承载力特性的重要因素,但是关于相贯角焊缝受力特点的研究尚不多见。实际工程中相贯节点除了承受轴向荷载外还受面内弯矩的作用,但是目前《钢结构设计规范》中仅给出支管受轴力作用下相贯节点承载力的计算公式,未对相贯节点面内抗弯承载力进行规定。本文对平面K型、空间KK型相贯节点进行模拟分析,考察角焊缝的应力分布、发展及其影响因素。通过T型圆钢管相贯节点面内抗弯承载力的试验研究、非线性有限元模拟以及计算理论分析,探讨了T型圆钢管相贯节点破坏模式、应变发展规律和抗弯承载力特性。本文的主要研究内容和结论如下：(1)平面K型相贯节点角焊缝的受力分析(支管-主管夹角=45°)建立平面K型相贯节点模型,分析支管在轴心拉、压力作用下角焊缝的受力特点,考察角焊缝的应力分布、发展及其影响因素。受拉支管、受压支管相贯角焊缝的最大、最小应力分别为鞍点、跟点；受拉支管相贯角焊缝的最大、最小平均应力分别为冠点、跟点,受压支管相贯角焊缝的最大、最小平均应力分别为鞍点、跟点。随着角焊缝高度的增大,应力差异变小。主管轴压力变化对角焊缝应力分布差异的影响较小。(2)空间KK型相贯节点角焊缝的受力分析建立空间KK型相贯节点模型,分析支管在轴心拉、压力作用下角焊缝的受力特点,考察角焊缝的应力分布、发展及其影响因素。受拉支管、受压支管相贯角焊缝的最大、最小应力分别为鞍点、跟点位置：受拉支管、受压支管相贯角焊缝的最大、最小平均应力分别为鞍点、跟点。随着角焊缝高度的增大,应力差异变小。主管轴压力变化对角焊缝应力分布差异的影响较小。(3)不同主管与支管连接角度时平面K型节点角焊缝的受力分析建立7种不同主管与支管连接角度的平面K型相贯节点模型,分析支管在轴心拉、压力作用下角焊缝的受力特点,考察角焊缝的应力分布、发展及其影响因素。主管与支管连接角度为90°、75°、60°时,受拉支管相贯角焊缝的最大、最小平均应力分别为鞍点、跟点；主管与支管连接角度为45°、37.5°时,受拉支管相贯角焊缝的最大、最小平均应力分别为冠点、跟点；主管与支管连接角度为30°、22.5°时,受拉支管相贯角焊缝的最大、最小平均应力分别为冠点、鞍点。主管与支管连接角度为90°、75°、60°、45°时,受压支管相贯角焊缝的最大、最小平均应力分别为鞍点、跟点；主管与支管连接角度为37.5°、30°、22.5°时,受压支管相贯角焊缝的最大、最小平均应力分别为冠点、跟点位置。(4)T型圆钢管相贯节点面内抗弯承载力计算理论开展T型圆钢管相贯节点面内抗弯承载力的试验研究、非线性有限元模拟,探讨了T型圆钢管相贯节点的破坏模式、应变发展规律和抗弯承载力特性；试验中主管受压侧应变发展较快,当节点荷载临近极限承载力时,T型相贯节点主管受压侧发生明显凹陷的局部屈曲；继续增加荷载,试验结束时焊缝产生撕裂破坏。同时,开展相贯节点的非线性有限元模拟,分析得到节点的失效模式、承载力与试验均吻合较好。基于试验研究和非线性有限元模拟,考察相贯节点抗弯承载力的主要影响因素,提出节点抗弯承载力计算理论；节点承载力的计算值与国外规范计算值、有限元模拟值吻合较好,验证所建议的相贯节点承载力计算理论合理正确。(5)设置加劲肋T型圆钢管相贯节点面内抗弯承载力特性开展设置加劲肋T型圆钢管相贯节点面内抗弯承载力的试验研究、非线性有限元模拟分析,探讨了设置加劲肋T型相贯节点的破坏模式、应变发展规律和抗弯承载力特性；试验中主管受压侧加劲肋附近应变发展较快,当节点荷载临近极限承载力时,节点主管受压侧加劲肋附近发生明显凹陷的局部屈曲,同时加劲肋发生面外弯曲失稳；设置加劲肋节点面内抗弯承载力比无加劲肋节点承载力明显提高,说明设置加劲肋后有效提高了节点抵抗变形的能力,增加了节点的刚度和强度,使节点承载力有大幅度的提升。同时,开展相贯节点的非线性有限元模拟,分析得到节点的失效模式、承载力与试验均吻合较好。基于非线性有限元模拟,考察加劲肋布置方式和尺寸对抗弯承载力的影响,提出合理的加劲肋布置方式。最后,对本文的研究工作进行归纳和总结,并提出了今后有待进一步解决的研究课题。
[Abstract]:In this paper , the stress distribution , strain development law and the influence factors of the intersecting joint of the T - shaped circular steel tube are discussed . The stress distribution , the development and the influence factors of the fillet weld are discussed .
In this paper , the maximum and minimum mean stress of the intersecting angle welding seam of the tension branch pipe is the saddle point and the heel point . The maximum and minimum mean stress of the fillet weld joint is smaller . The stress distribution , development and the influence factors of the angle weld are analyzed .
When the connection angle of the main pipe and branch pipe is 45 掳 and 37.5 掳 , the maximum and minimum mean stress of the intersecting angle welding seam of the supported pipe are respectively the crown point and heel point ;
When the connection angle of the main pipe and branch pipe is 30 掳 and 22.5 掳 , the maximum and minimum mean stress of the intersecting angle welding seam of the supported pipe are respectively the crown point and saddle point . When the connection angle of the main pipe and branch pipe is 90 掳 , 75 掳 , 60 掳 and 45 掳 , the maximum and minimum mean stress of the intersecting angle welding seam of the compression branch pipe are saddle points and heel points , respectively ;
In this paper , the maximum and minimum mean stress of the intersecting angle welding seam of T - shaped circular steel tube are studied by using the calculation theory of the bending bearing capacity of T - shaped circular steel tube intersecting node . The failure mode , the strain development law and the bending bearing capacity of T - shaped circular steel tube are discussed .
In the test , the strain development of the main pipe under pressure is faster , and when the load of the node is close to the ultimate bearing capacity , the local buckling of the pressure side of the T - shaped intersecting node is obvious ;
At the same time , the non - linear finite element simulation of the intersecting node is carried out , the failure mode of the node is analyzed , and the bearing capacity and the test are in good agreement . Based on the experimental research and the nonlinear finite element simulation , the main influencing factors of the bending bearing capacity of the intersecting node are investigated , and the calculation theory of the bending bearing capacity of the node is proposed .
The calculation values of the bearing capacity of the joints are in good agreement with those of the overseas codes and the finite element simulation values are in good agreement with each other .
In the test , the strain development near the compression side stiffening rib is faster . When the load of the node approaches the ultimate bearing capacity , the local buckling of the obvious depression near the compression side of the node is locally buckled , while the external buckling of the stiffening rib is unstable ;
Based on the non - linear finite element simulation , the paper studies the influence of stiffened rib arrangement way and size on the bending bearing capacity and puts forward a reasonable arrangement mode of stiffening rib . Finally , the research work of this paper is summarized and summarized , and the research subject to be further resolved in the future is put forward .

【学位授予单位】：南京工业大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TU392.3

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