拱形波纹腹板钢曲梁的承载力研究

发布时间：2018-03-22 09:13

本文选题：拱形波纹腹板钢曲梁　切入点：有限元分析　出处：《西安工业大学》2017年硕士论文　论文类型：学位论文

【摘要】：拱形波纹腹板钢曲梁作为一种新型结构构件,它结合了波纹腹板钢直梁与拱形钢曲梁的优势,在大跨度空间结构、桥梁方面都有所应用。但对其具体的内力变化规律、抗弯承载力、抗剪承载、整体稳定性及局部稳定性研究甚少。本论文根据开口薄壁构件的基本假设,从精准翘曲理论位移表达式出发,借助能量守恒定律及虚功原理,对薄壁曲梁进行了详细的阐述分析,推导出了在考虑几何非线性情况下曲梁的总势能表达式,在根据欧拉公式得到了曲梁的稳定平衡微分方程。通过有限元软件ANSYS建模分析了,在跨中集中荷载作用下、均布径向荷载作用下,两端固接的拱形波纹腹板钢梁与拱形工字钢梁的vovMises stress应力变化云图、1st Principal stress应力变化云图、XY shear stress应力变化云图及Y-Component of displacement位移变化云图的对比,得出拱形波纹腹板钢曲梁的上下翼缘板基本只承担弯矩和轴力,拱形波纹腹板基本只承担剪力,其性能基本都强于拱形工字钢曲梁。通过有限元软件ANSYS,对拱形波纹腹板钢梁的实体建模、划分网格、加载及求解都进行了详细介绍。分析了两端固接拱形波纹腹板钢曲梁与拱形工字钢曲梁在跨中集中荷载作用下,特征值屈曲的一阶～五阶模态对比图,其特征屈曲值远高于拱形工字钢曲梁。也对非线性屈曲进行分析,得到一系列荷载—位移曲线图及极限荷载值,得出其平面外横向位移始终大于平面内竖向位移,其容易发生平面外弯扭屈曲失稳。改变拱形波纹腹板钢曲梁的正弦波纹半波长、波高、腹板高度与厚度、翼缘板宽度与厚度、初始缺陷设置及圆心角,通过ANSYS分析整理,分别绘制了平面外水平位移u随荷载P变化的曲线图,平面内的竖向位移v随荷载P变化的曲线图,绕拱梁纵轴扭转的扭转角0随荷载P变化的曲线图,以及极限荷载值和极限荷载值所对应的位移值。得出随着波高、腹板高与腹板厚、翼缘宽与翼缘厚的增加,极限承载能力增强;随着半波长、初始缺陷、圆心角的增大,极限承载能力减小。拱形波纹腹板钢曲梁易发生弯扭屈曲。在均布径向荷载作用下,两端铰接拱形工字钢曲梁的弯扭屈曲临界轴力计算公式和在两端等弯矩作用下,简支拱形工字钢曲梁的弯扭屈曲临界弯矩计算公式,分别与波纹腹板钢直梁的波纹腹板等效刚度进行组合,得出拱形波纹腹板钢曲梁承载力的组合公式。但因为波纹腹板等效刚度没有考虑拱梁曲率的影响,所以,通过ANSYS分析曲率对拱形波纹腹板钢曲梁的影响,将有限元值与组合公式计算值进行对比分析,且对其比值进行多元线性回归分析,拟合出修正系数公式,加以修正组合公式。在一般荷载作用下,拱形波纹腹板钢曲梁属于压弯构件,平衡微分方程没有解析解,根据压弯构件的相关分析结果对其进行多元线性回归分析,得出在一般荷载作用下,拱形波纹腹板钢曲梁弹性弯扭屈曲的内力判别式。
[Abstract]:As a new type of structural member, arch corrugated web steel curved beam combines the advantages of corrugated web steel straight beam and arch steel curved beam, and is used in large span spatial structure and bridge. There are few studies on bending capacity, shear bearing capacity, global stability and local stability. According to the basic assumptions of thin-walled members with openings, this paper starts from the accurate displacement expression of warping theory, with the aid of the law of conservation of energy and the principle of virtual work. In this paper, the thin walled curved beam is analyzed in detail, and the total potential energy of curved beam is derived under the condition of geometric nonlinearity. According to the Euler formula, the stable equilibrium differential equation of curved beam is obtained. The finite element software ANSYS is used to model and analyze the equation. Under the action of concentrated load in span and uniform radial load, VovMises stress stress change of arch corrugated web beam and arch I-shaped steel beam at both ends; comparison of XY shear stress stress change cloud diagram and Y-Component of displacement displacement change cloud diagram with 1st Principal stress stress change cloud diagram, It is concluded that the upper and lower flange plates of arch corrugated web steel curved beam bear only bending moment and axial force, and arch corrugated web bear shear force. Its performance is basically better than that of arch I-shaped steel curved beam. Through finite element software ANSYS, the solid model of arch corrugated web plate steel beam is built and meshed. The loading and solving methods are introduced in detail. The first ~ fifth order modal comparison diagram of eigenvalue buckling between the fixed arch corrugated steel curved beam and the arch I-shaped steel curved beam under concentrated load in the span is analyzed. Its characteristic buckling value is much higher than that of arch I-beam. A series of load-displacement curves and ultimate load values are obtained by analyzing nonlinear buckling. It is concluded that the lateral displacement is always larger than the vertical displacement in the plane. The bending and torsional buckling of the arch corrugated web steel curved beam is prone to buckling instability in plane. The half-wavelength, wave height, web height and thickness, the width and thickness of flange plate, the initial defect setting and the center angle of the arch corrugated web steel curved beam are changed and analyzed by ANSYS. The curves of horizontal displacement u with load P, vertical displacement v with load P and torsion angle 0 of longitudinal axis around arch beam with load P are plotted respectively. With the wave height, the web height and the web thickness, the flange width and the flange thickness, the ultimate bearing capacity increases, with the increase of the half wavelength, the initial defect, the center angle, the displacement value corresponding to the limit load value and the limit load value, the maximum bearing capacity increases with the increase of the wave height, the web height and the web thickness, the flange width and the flange thickness. The ultimate bearing capacity is reduced. The bending and torsional buckling of arch corrugated web steel curved beam is easy to occur. Under uniform radial load, the critical axial force of bending and torsional buckling of two ends of arch I-shaped steel curved beam is calculated under uniform radial load, and under the action of equal bending moment at both ends, The formulas for calculating the critical moment of bending and torsional buckling of simply supported arch I-beam curved beams are combined with the equivalent stiffness of corrugated webs of steel straight beams with corrugated webs, respectively. The combined formula of bearing capacity of arch corrugated web steel curved beam is obtained. However, because the equivalent stiffness of corrugated web does not consider the influence of arch beam curvature, the influence of curvature on arch corrugated web steel curved beam is analyzed by ANSYS. The finite element value is compared with the calculated value of the combination formula, and the ratio is analyzed by multivariate linear regression analysis. The modified coefficient formula is fitted and the combined formula is modified. The arch corrugated web steel curved beam belongs to the compression and bending member, and the equilibrium differential equation has no analytical solution. According to the correlation analysis result of the compression and bending member, the multivariate linear regression analysis is carried out, and it is concluded that under the general load, Internal force discriminant of elastic bending and torsional buckling of arch corrugated web steel curved beam.
【学位授予单位】：西安工业大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TU391

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