At present, the main methods of simulating structural collapse can be summarized as follows. Therefore, the numerical simulation method is widely adopted for the collapse process of structures. In addition, conducting structural collapse tests is expensive and dangerous, and the experimental process is difficult to control. Given that the collapse process of structures involves many complicated nonlinear cases, theoretical analysis is difficult and cannot accurately evaluate the structural failure mechanisms. Three main methods can be used to analyze structural progressive collapse: theoretical analysis, experimental study, and numerical simulation. They concluded that the transmission tower was more prone to collapsing under three-dimensional earthquake action. The weak parts of transmission towers were analyzed.
used the finite element software ABAQUS, to develop a subroutine based on the idea of the birth-death element to simulate the progressive collapse of transmission towers subjected to one-dimensional and three-dimensional earthquake, respectively.
established a finite element model by using the beam element and the truss element and conducted a dynamic response analysis of self-supporting and guyed transmission towers induced by wind loads, respectively, and the quality of conductors and insulators was concentrated to arms or nodes of the finite element model. The results of numerical simulation were highly consistent with those of structural tests, and they significantly improved the computational efficiency. They deduced the element stiffness matrix by considering initial stress, initial deformation, and geometry. established a space rigid frame model to analyze the correlations of transmission towers. analyzed the structure of transmission towers by using the space frame model or the space truss model and discovered that the damping ratio of a 45 m high transmission tower varied between 0.015 and 0.04.
The seismic dynamic responses of transmission towers involve initially solving a mechanical model, and its analysis involves many nonlinear problems, such as dynamic nonlinearity, geometric nonlinearity, and material nonlinearity. Figure 1 depicts the collapse of transmission towers during the earthquake.Ĭollapse of transmission steel towers during Wenchuan earthquake in China (2008). Moreover, transmission lines also broke down in the Wenchuan earthquake in China in 2008. The Kocaeli earthquake in Turkey in 1999 also caused landslides, faulting, and ruptures of earth’s surface, thereby damaging a considerable number of transmission towers. The Kobe earthquake in Japan in 1955 resulted in the destruction of a large number of transmission towers whose main failure modes were the subsidence of foundation, the tilt of tower, and compressive yield of structural member.
In the United States, the Landers earthquake in 1992 and the Northridge earthquake in 1994 severely damaged the transmission system, respectively. The breakdown or collapse of transmission towers is common during an earthquake. The result indicates that the transmission steel tower has better seismic safety performance and anticollapse ability. Finally, the collapse simulation of the transmission steel towers subjected to unidirectional earthquake ground motion and the collapse seismic fragility analysis can be successfully carried out using the finite particle method. To simulate the collapse of the transmission steel tower, a failure criterion based on the ideal elastic-plastic model and a failure mode are proposed. And the static and elastic seismic response analyses indicate that the results of the FPM agree well with those of the FEM. This paper employs the finite particle method (FPM) to simulate the collapse of a transmission steel tower under earthquake ground motions the three-dimensional (3D) finite particle model using MATLAB and the 3D finite element model using ANSYS of the transmission steel tower are established, respectively.
Particles are free to separate from one another, which is advantageous in the simulation of the structural collapse. Simulation of the process of collapse is difficult using traditional finite element method (FEM), which is generated from continuum and variation principle, whereas the finite particle method (FPM) enforces equilibrium on each point.
The collapse of transmission towers involves a series of complex problems, including geometric nonlinearity, material nonlinearity, dynamic nonlinearity, and the failure of members.