履带式起重机的折线式臂架是典型的细长框架结构，臂架结构的稳定性是系统起重性能一个重要依据。以每个臂节为单位对臂架结构划分多个子结构，建立随子结构一起运动的随动坐标系。通过自由度凝聚，将子结构的内部位移凝聚到边界端面上。基于共旋坐标法，推导子结构单元的广义节点内力。考虑到臂架结构受到的机构约束和重物提升方式，给出由于机构位移和吊重附加在臂架结构上的广义节点外力及其对结构位移和机构位移的导数。对含载荷参数的臂架结构节点力平衡方程求导，得到一组微分方程，通过求解微分方程并结合失稳判断准则可以得到臂架结构的失稳载荷。通过数值算例，说明该方法在快速求解履带式起重机折线式臂架结构的失稳载荷方面具有很好的速度和精度。

The hinged boom structures of crawler cranes are typical slender frame structures, whose stability is an important basis for lifting performance. The boom structures are divided into several substructures by taking each section as an element, and an embedded coordinate system is defined. Internal displacements of each substructure are reduced to the displacements of its boundary ends through the condensation of degrees of freedom. Based on the co-rotational method, the generalized nodal internal forces for substructure elements are formulated. Considering the mechanism constraints for the boom structures and the load lifting ways, the additional nodal external forces and their derivatives on the structure and mechanism displacements are obtained. The equations by differentiating the equilibrium equations of generalized nodal forces for the boom structures of crawler cranes with respect to the load factor are obtained. The critical load can be obtained through solving the differential equations and considering the instability criterion. A numerical example of hinged boom structures for a kind of crawler crane is given, which proves the presented method to be quick and high accuracy.