摘要
既有梁-柱结构的服役荷载主要形式以轴力产生的偏压荷载以及垂直于梁柱结构轴线的服役荷载为主。目前,针对细长结构压弯耦合荷载导致的稳定性问题,主要采用2种方法进行结构分析,即特征值法和荷载-挠度法。由于实际桥梁构件存在一定的几何缺陷和材料刚度退化,采用忽略非线性的特征值法会高估承载能力。以任意截面形式组成的简支梁为例,基于Ritz法,并结合能量平衡条件,分别建立了考虑几何非线性和材料非线性的简支梁-柱结构在偏压荷载和多种竖向作用耦合作用下的第二类稳定解析分析模型,并建立了不同初始缺陷的变截约束混凝土柱有限元分析模型。研究结果表明:解析模型结果与有限元结果相比较,二者吻合良好。建立的解析模型可以精确考虑双重非线性的二阶效应。
The service load of the existing beam-column structure is mainly the partial load generated by axial force and the service load perpendicular to the axis of the beam-column structure.At present,two methods are mainly used to analyze the stability of slender structures caused by coupled flexural loads,that is,eigenvalue method and load-deflection method.Due to the geometric defects and material stiffness degradation of the actual bridge members,the bearing capacity will be overestimated by using the eigenvalue method which ignores the nonlinearity.Based on the Ritz method and combined with the energy balance condition,this paper established the second type of stability analytical analysis model of the simple supported beam-column structure with geometric and material nonlinearity under the coupling of biased load and multiple vertical actions.The finite element analysis models of concrete columns with different initial defects are established.By comparing the analytical model results with the finite element results,it is found that the above two model are in good agreement,and the established analytical model can accurately consider the double nonlinear second-order effect.
作者
韩旭
李万恒
李鹏飞
肖建宇
刘耀阳
HAN Xu;LI Wanheng;LI Pengfei;XIAO Jianyu;LIU Yaoyang(Research Institute of Highway Ministry of Transport,Beijing 100088,China;School of Civil Engineering,Beijing Jiaotong University,Beijing 100044,China)
出处
《铁道建筑》
北大核心
2024年第9期53-62,共10页
Railway Engineering
基金
国家重点研发计划(2021YFB3202900)。
关键词
梁-柱结构
双重非线性
服役性能
RITZ法
偏心受压荷载
荷载-变形曲线
beam-column structure
dual nonlinearity
service performance
Ritz method
eccentric compression load
load-deformation curve
