Nonlinear Finite Element Analysis of Beam String Structure

Abstract

Beam string structure (BSS), which is a new kind of semi-rigid hybrid system, composed of arch, strut and string, has been developed rapidly in long-span steel structures in recent years. Based on the principle of virtual work and Updated Lagrange, the formulas of geometric nonlinear F.E.M. for spatial beam element, cable element and truss element are derived respectively in this paper. Taking the one-way BSS model of the steel roof in Guangzhou International Convention and Exhibition Center as a computational example by using both linear and nonlinear analysis method, the analytical results show that it is appropriate when adopting the straight truss element with two joints and equivalent elastic modulus to simulate the cable element with small sag. Although the linear analysis can meet the requirement of practical engineering due to its weak nonlinearity of BSS, the nonlinear method is also important to improve the precision theoretically. The conclusions obtained may be helpful for the designers in similar projects.

An Adaptive Operational Modal Analysis Method Using Encoder LSTM with Random Decrement Technique

“…Here, the encoder LSTM was established by repeatedly training with the iteration steps as 100 and the learning rate as 0.001. It is widely known that the finite element method can be directly used to solve the modal parameters of beam [28,29]. And the natural frequency equation can be determined by the vibration differential equation [30] and boundary conditions, and then, the natural frequencies of the beam can be obtained.…”

Comparisons of design methods for beam string structure based on reliability and progressive collapse analysis

“…dead load partial factor γg, live load partial factor γq, resistance partial factor γR) are used, then Eq. ( 12) can be rewritten as (13) In order to verify the accuracy of the simplified method, two typical cases (K=1.7, rn=4.0;…”

“…To improve the calculation efficiency, many analysis methods for BSS have also been proposed. For example, Thai et al [11] and Abad et al [12] proposed new elements for nonlinear finite element analysis of cables under static and dynamic loads, and also presented algorithms for calculating the stiffness matrix and internal force vector; Jiang et al [13] derived the formulas of geometric nonlinear FEM for spatial beam element, cable element and truss element, respectively. Wu et al [14,15] investigated the variation of the lateral buckling of the struts in the BSS for different string layouts, and deduced the formulas for calculating the critical buckling load of struts in the BSS.…”