装配式地铁车站结构接头非线性弯曲模式识别

Identification of Nonlinear Bending Modes in Joints of Assembled Subway Stations

摘要:

为了探究装配式结构环向接头在弯矩和轴力共同作用下产生的非线性特征，基于接头处的接触状态、受力特征和变形协调关系，提出了压弯、纯弯和拉弯受力状态下的力学模型，分析了弯曲变形发展过程的内力区域分布及其识别方法，并运用三维数值模型进行验证。研究发现，接头的主要变形历程可由4种弯曲模式进行表征，将具体构件尺寸和材料参数代入相关转角表达式中即可判断接头处于何种发展过程。通过现场实测弯矩值和轴力值可准确识别环向接头的弯曲模式，并给出接头随弯矩变化的力学特征及安全状态。

Abstract:

This paper investigated the nonlinear characteristics of the annular joints of assembled structures under the action of bending moment and axial force. Based on the contact state， force characteristics， and deformation coordination relationship at joints， a mechanical model was proposed for the stress states of compression-bending， pure bending， and tension-bending. The distribution of internal force regions in the development process of bending deformation and its identification method were analyzed. A three-dimensional numerical model was adopted to validate it. It is shown that the main deformation process of the joint can be characterized by four bending modes. The specific dimensions and material parameters of the components can be substituted into the relevant angle expressions to determine the development process of joints. On-site measurement of bending moment and axial force indicates that the bending modes of the annular joint can be accurately identified， and the mechanical characteristics and safety status of the joint can be provided.