Modeling of connections in the analyses of thin-walled space frames

Nonlinear Analysis of RC Box Culverts Resting on a Linear Elastic Soil

“…To this purpose, the efficient procedure proposed by Hasan et al (2002) for pushover analysis of framed structures is modified by adopting the semi-rigid joint model proposed by Shakourzadeh et al (1999). The resulting procedure allows to account for structural nonlinear behavior by placing potential plastic el.…”

“…In particular, the rotational stiffness of a semi-rigid connection at the kth node (Chen and Lui, 2005) is substituted by the postelastic bending stiffness R k = dM k /dθ k of the crosssection (Hasan et al, 2002). Moreover, the simple procedure proposed by Shakourzadeh et al (1999) is adopted for taking account of the plastic hinge M-θ relation. Consequently, considering a beam FE with flexural plastic hinges located at the end nodes only and introducing the vector of post-elastic nodal displacements q j = {w 1 , θ 1 , w 2 , θ 2 } T , the joint constitutive relation may be written in the form:…”

“…where, correction matrix C (Shakourzadeh et al, 1999;Minghini et al, 2009;2010) depends on the stiffness matrix of the element and on the plastic hinge stiffnesses collected in K j :…”

“…They considered potential plastic hinge sections in frame members as semirigid connections with predefined load-deformation characteristics; then, the stiffness matrix of the member was modified without adding further elements and degrees of freedom to the discrete model of the structure. Furthermore, Shakourzadeh et al (1999) defined a procedure for taking account of the semi-rigid joint deformation of threedimensional thin-walled frames considering membrane, shear, bending, torsion and warping effects. Minghini et al (2009;2010) adopted Shakourzadeh et al's (1999) model for the buckling and vibration analyses of pultruded frames with semi-rigid connections.…”

“…To this aim, the method proposed by Hasan et al (2002) is modified by incorporating the model of Shakourzadeh et al (1999). For simplicity, a rigid-perfectly-plastic relation is adopted to describe the moment-rotation relationship of plastic hinges.…”