哑铃型钢管混凝土拱肋极限承载力的线弹性分析方法

发布时间：2018-02-01 04:35

本文关键词： 桥梁工程极限承载力弹性模量缩减法钢管混凝土哑铃型拱肋广义屈服函数　出处：《交通运输工程学报》2017年03期 　论文类型：期刊论文

【摘要】：为了提高哑铃型钢管混凝土拱肋极限承载力的计算效率,提出了极限承载力分析的高效自适应弹性模量缩减法;根据连续条件和截面塑性承载性能,建立了钢管混凝土哑铃型构件压弯承载力相关方程,通过回归分析得到了相应的齐次广义屈服函数;采用单一组合材料梁单元建立了拱肋的线弹性有限元迭代模型,通过自适应缩减高承载单元弹性模量模拟结构在加载过程中的刚度损伤,确定拱肋的极限承载力,并与模型试验、非线性有限元法和等效梁柱法计算结果进行了对比。计算结果表明:建立的齐次广义屈服函数计算结果稳定、可靠,克服了传统广义屈服函数计算结果受荷载初始值影响的缺陷;采用自适应弹性模量缩减法只需较少的离散单元数与迭代步数即可获得稳定的极限承载力,且与模型试验结果误差小于3%,计算耗时小于16s,相对非线性有限元法具有良好的计算精度和效率;哑铃形截面拱肋相比圆形截面拱肋具有更好的承载性能,矢跨比、含钢率和荷载作用方式是影响钢管混凝土拱肋极限承载力的重要因素;随着矢跨比增大,极限承载力增速减缓;随着含钢率增大,极限承载力几乎呈线性增长;随着集中力与均布力比值增大,其对极限承载力的影响逐渐减弱;轴力与弯矩是拱肋的主要内力,随着矢跨比增大,弯矩对极限承载力的影响更加显著。
[Abstract]:In order to improve the calculation efficiency of ultimate bearing capacity of concrete filled dumbbell concrete filled steel tube arch rib, an efficient adaptive elastic modulus reduction method for ultimate bearing capacity analysis is proposed. According to the continuous condition and the plastic bearing capacity of section, the equation of compressive and bending bearing capacity of concrete filled steel tube (CFST) dumbbell member is established, and the corresponding homogeneous generalized yield function is obtained by regression analysis. The linear elastic finite element iteration model of arch rib is established by using a single composite material beam element, and the stiffness damage of the structure during loading is simulated by adaptively reducing the elastic modulus of high bearing element. The ultimate bearing capacity of arch rib is determined and compared with model test, nonlinear finite element method and equivalent Liang Zhu method. The results show that the calculated results of homogeneous generalized yield function are stable and reliable. It overcomes the limitation that the results of the traditional generalized yield function are affected by the initial value of the load. The adaptive elastic modulus reduction method requires only a small number of discrete elements and iterative steps to obtain a stable ultimate bearing capacity, and the error is less than 3 with the result of the model test, and the calculation time is less than 16 seconds. Compared with nonlinear finite element method, it has good accuracy and efficiency. The dumbbell section arch rib has better bearing capacity than circular section arch rib. The ratio of rise-span, steel content and load mode are the important factors that affect the ultimate bearing capacity of concrete-filled steel tubular arch rib. With the increase of rise-span ratio, the growth rate of ultimate bearing capacity slows down. With the increase of steel content, the ultimate bearing capacity increases linearly. With the increase of the ratio of concentrated force to uniform force, the influence on ultimate bearing capacity decreases gradually. Axial force and bending moment are the main internal forces of arch rib. With the increase of rise-span ratio, the influence of bending moment on ultimate bearing capacity is more significant.
【作者单位】：广西大学防灾减灾与工程安全广西重点实验室;广西大学工程防灾与结构安全教育部重点实验室;
【基金】：国家自然科学基金项目(51478125,51469004) 广西自然科学基金项目(2012GXNSFEA053002)
【分类号】：U441
【正文快照】： 0引言钢管混凝土(Concrete-Filled Steel Tubular,CFST)哑铃型拱桥具有良好的受力性能,在工程中应用广泛[1]。目前,CFST哑铃型拱肋承载力的研究方法主要分为3类:试验法、解析法和数值法。试验法能较真实地揭示结构承载性能,往往可作为检验其他方法正确性的基准。曾国锋等开展

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