Seismic Analysis of a Buried Operating Steel Pipeline with Emphasis on the Equivalent-Boundary Conditions

2018 ◽  
Vol 9 (3) ◽  
pp. 04018005 ◽  
Author(s):  
G. Banushi ◽  
N. Squeglia
2013 ◽  
Vol 459 ◽  
pp. 608-613 ◽  
Author(s):  
Joanna M. Dulinska ◽  
Dorota Jasinska

The paper presents the analysis of the dynamic response of a steel pipeline with concrete coating to a real earthquakeregistered in central Poland in 2012. The peak ground acceleration of the shock was scaled up to maximal values predicted for this seismic zone. To represent theinelastic behavior of the material of the concrete coating under dynamic loading, the concrete damaged plasticity constitutive model was assumed.The modelallows to describeplastic strains and irreversible tensile and compression damage that occurs during the cracking process.For seismic analysis two models (uniform and non-uniform) of kinematic excitation were applied. In the modelof uniform excitation it was assumed that the motion of all supports was identical. Inthe model of non-uniform excitation, typical for long structures, the wave passage along the pipelinewith different velocities (500, 400 and 300 m/s) was taken into account. It occurred that for the model of uniform excitation the concrete material of the coating remained elastic with no tensile damage. For the model of non-uniform excitation, inelastic behaviour of the coating was observed. The plastic strain areas appeared above all supports. The tensile damage (cracking) wasalso noticed in these areas: the lower wave velocity was assumed, the greater area of concrete coating was affected by plastic strains and tensile damage (cracking). It was the consequence of the quasi-static effects which resulted from ground deformations imposed on the pipeline during the seismic shock.


2020 ◽  
Vol 310 ◽  
pp. 00032
Author(s):  
Lubomir Prekop

The paper deals with dynamic analysis of a container. The analyzed structure consists of a steel support structure and a cylindrical container. The container is used for storage of road salt and other spreading materials during winter road maintenance. Three variants of support system of a structure have been analyzed. These have been introduced into the model as different boundary conditions. The modal analysis was performed, whose results are eigenfrequencies and eigenshapes of the structure. In the final part, the results obtained from the seismic analysis of the structure (displacements and internal forces) have been presented.


2016 ◽  
Vol 2016 ◽  
pp. 1-9
Author(s):  
Li Tian ◽  
Xia Gai

Nonlinear seismic behaviors of different boundary conditions of transmission line system under earthquake loading are investigated in this paper. The transmission lines are modeled by cable element accounting for the nonlinearity of the cable. For the suspension type, three towers and two span lines with spring model (Model 1) and three towers and four span lines’ model (Model 2) are established, respectively. For the tension type, three towers and two span lines’ model (Model 3) and three towers and four span lines’ model (Model 4) are created, respectively. The frequencies of the transmission towers and transmission lines of the suspension type and tension type are calculated, respectively. The responses of the suspension type and tension type are investigated using nonlinear time history analysis method, respectively. The results show that the responses of the transmission tower and transmission line of the two models of the suspension type are slightly different. However, the responses of transmission tower and transmission line of the two models of the tension type are significantly different. Therefore, in order to obtain accurate results, a reasonable model should be considered. The results could provide a reference for the seismic analysis of the transmission tower-line system.


2014 ◽  
Vol 15 (3) ◽  
pp. 301
Author(s):  
Manuela Longoni De Castro ◽  
Julien Diaz ◽  
Victor Perón

In this work, we have worked on possibilities to model artificial boundaries needed in the simulation of wave propagation in acoustic heterogeneous media.  Our motivation is to restrict the computational domain in the simulation of seismic waves that are propagated from the earth and transmitted to the stratified heterogeneous media composed by ocean and atmosphere. Two possibilities were studied and compared in computational tests: the use of absorbing boundary conditions on an artificial boundary in the atmosphere layer and the elimination of the atmosphere layer using an equivalent boundary condition that mimics the propagation of waves through the atmosphere. <br />


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