scholarly journals Spherical-Earth finite element model of short-term postseismic deformation following the 2004 Sumatra earthquake

2012 ◽  
Vol 117 (B5) ◽  
pp. n/a-n/a ◽  
Author(s):  
Yan Hu ◽  
Kelin Wang
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Element Model ◽  
Postseismic Deformation ◽  
Sumatra Earthquake ◽  
Short Term ◽  
2004 Sumatra Earthquake ◽  
Spherical Earth

Short-Term Mechanical Analysis of Polyethylene Pipe Reinforced by Winding Steel Wires Using Steel Wire Spiral Structural Finite Element Model

2017 ◽  
Author(s):  
Jun Shi ◽  
Jianfeng Shi ◽  
Hanxin Chen ◽  
Yibin He ◽  
Qingjun Wang ◽  
...  
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Nonlinear Model ◽  
Steel Wire ◽  
Element Model ◽  
Experimental Result ◽  
Short Term ◽  
Polyethylene Pipe ◽  
Steel Wires ◽  
Calculation Results

Polyethylene pipe reinforced by winding steel wires (PSP) is new type of polymer-matrix composite pipe, which is widely used in petroleum, chemical engineering, and water supply, etc. PSP is composed of a thermoplastic core pipe (HDPE), an outer cover layer (HDPE), and steel wire skeleton sandwiched in the middle. The steel wire skeleton is formed by crossly winding steel wires integrated with HDPE matrix by cohesive resin. In traditional analysis models of PSP, components of PSP were considered linear elastic, and steel wire skeleton was assumed to be orthotropic composite layer based on the classical laminated plate theory. Although achieving good results in engineering applications, traditional models neglected the material nonlinearity of steel wires and HDPE matrix, which was significant to failure analysis. In the present paper, a new finite element model was constructed using commercial software ABAQUS[1], based on the actual steel wire spiral structure of PSP. Steel wires and HDPE matrix were modeled separately, which were both represented by solid elements, and the interaction between steel wires and HDPE was characterized by tie interaction. Experimental result of short-term burst pressure of PSP was used to validate the nonlinear model. Compared with the experimental result, the calculation results of the nonlinear model agreed well. Furthermore, the effect of the nonlinear material property of components on the calculation results were investigated, and the short-term mechanical responses of PSP were determined and analyzed through the nonlinear model.

scholarly journals Probing afterslip and viscoelastic relaxation following the 2015 Mw 7.8 Gorkha earthquake based on the 3-D Finite Element Model

2020 ◽  
Author(s):  
Lina Su ◽  
Fuqiang Shi ◽  
Weijun Gan ◽  
Xiaoning Su ◽  
Junyi Yan
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Material Properties ◽  
Element Model ◽  
Postseismic Deformation ◽  
Earth Model ◽  
Viscoelastic Relaxation ◽  
Gorkha Earthquake ◽  
2015 Gorkha Earthquake ◽  
Continuous Gps

Abstract We analyzed GPS coordinate time series from 34 continuous GPS stations in Nepal and 5 continuous GPS stations in South Tibet of China, and extracted the first 4.8 years postseismic displacements after the 2015 Mw7.8 Gorkha earthquake. With the longer duration GPS observations, we found that postseismic displacements mainly exhibit the southward and uplift movement at the epcientral area. To study the postseismic afterslip and viscoelastic relaxation, we then built 3-D spherical finite element model (FEM) with heterogeneous material properties and surface topography across the Himalayan range, accounting for the strong variations of material properties and surface elevation along central Himalayan arc. The sophisticated FEM is more realistic and perform better than the flat layered earth model. On the basis of it, we reveal that the predicted viscoelastic relaxation of cm level is opposite to the observed postseismic deformation; the postseismic deformation with viscoelastic relaxation deducted is well explained by afterslip downdip of coseismic rupture, which indicates the afterslip is still dominant during 4.8 years postseismic deformation after the 2015 Mw7.8 Gorkha earthquake; The lack of slip on a shallow portion and western segment of the MHT during and after the 2015 Gorkha earthquake implies continued seismic hazard in the future.

scholarly journals Probing time-dependent afterslip and viscoelastic relaxation following the 2015 Mw 7.8 Gorkha earthquake based on the 3-D Finite Element Model

2020 ◽  
Author(s):  
Lina Su ◽  
Fuqiang Shi ◽  
Weijun Gan ◽  
Xiaoning Su ◽  
Junyi Yan
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Material Properties ◽  
Heterogeneous Material ◽  
Element Model ◽  
Postseismic Deformation ◽  
Viscoelastic Relaxation ◽  
Gorkha Earthquake ◽  
2015 Gorkha Earthquake ◽  
Continuous Gps

Abstract We analyzed daily displacement time series from 34 continuous GPS stations in Nepal and 5 continuous GPS stations in South Tibet, China, and extracted the first 4.8 years of postseismic motion after the 2015 Mw7.8 Gorkha earthquake. With the longer duration GPS observations, we find that postseismic displacements mainly exhibit southward and uplift motion. To study the postseismic afterslip and viscoelastic relaxation, we built a 3-D spherical finite element model (FEM) with heterogeneous material properties and surface topography across the Himalayan range, accounting for the strong variations in material properties and surface elevation along central Himalayan arc. On the basis of the FEM, we reveal that the predicted viscoelastic relaxation of cm level moves southward to the north of the Gorkha earthquake rupture, but in an opposite direction to the observed postseismic deformation in the south; the postseismic deformation excluding viscoelastic relaxation is well explained by afterslip downdip of the coseismic rupture. The afterslip is dominant during 4.8 years after the 2015 Mw7.8 Gorkha earthquake; the contribution by the viscoelastic relaxation gradually increases slightly. The lack of slip on a shallow portion and western segment of the MHT during and after the 2015 Gorkha earthquake implies continued seismic hazard in the future.

scholarly journals Probing afterslip and viscoelastic relaxation following the 2015 Mw 7.8 Gorkha earthquake based on the 3-D Finite Element Model

2020 ◽  
Author(s):  
Lina Su ◽  
Fuqiang Shi ◽  
Weijun Gan ◽  
Xiaoning Su ◽  
Junyi Yan
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Material Properties ◽  
Heterogeneous Material ◽  
Element Model ◽  
Postseismic Deformation ◽  
Viscoelastic Relaxation ◽  
Gorkha Earthquake ◽  
2015 Gorkha Earthquake ◽  
Continuous Gps

Abstract We analyzed daily displacement time series from 34 continuous GPS stations in Nepal and 5 continuous GPS stations in South Tibet, China, and extracted the first 4.8 years of postseismic motion after the 2015 Mw7.8 Gorkha earthquake. With the longer duration GPS observations, we find that postseismic displacements mainly exhibit southward and uplift motion. To study the postseismic afterslip and viscoelastic relaxation, we built a 3-D spherical finite element model (FEM) with heterogeneous material properties and surface topography across the Himalayan range, accounting for the strong variations in material properties and surface elevation along central Himalayan arc. On the basis of the FEM, we reveal that the predicted viscoelastic relaxation of cm level moves southward to the north of the Gorkha earthquake rupture, but in an opposite direction to the observed postseismic deformation in the south; the postseismic deformation with viscoelastic relaxation is well explained by afterslip downdip of the coseismic rupture, which is still dominant 4.8 years after the 2015 Mw7.8 Gorkha earthquake. The lack of slip on a shallow portion and western segment of the MHT during and after the 2015 Gorkha earthquake implies continued seismic hazard in the future.

scholarly journals A global,spherical,finite-element model for postseismic deformation using ABAQUS

2020 ◽  
Author(s):  
Grace A. Nield ◽  
Matt A. King ◽  
Rebekka Steffen ◽  
Bas Blank
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Active Regions ◽  
Element Model ◽  
Postseismic Deformation ◽  
Multiple Sources ◽  
Rheological Models ◽  
Tectonically Active ◽  
Self Gravity ◽  
Lateral Variations

Abstract. We present a finite-element model of postseismic solid Earth deformation built in the software package ABAQUS (version 2018). The model is global and spherical, and includes self-gravitation and is built for the purpose of calculating postseismic deformation in the far-field (> ~ 300 km) of major earthquakes. An earthquake is simulated by prescribing slip on a fault plane in the mesh and the model relaxes under the resulting change in stress. Both linear Maxwell and biviscous (Burgers) rheological models have been implemented and the model can be easily adapted to include different rheological models and lateral variations in Earth structure, a particular advantage over existing models. We benchmark the model against an analytical coseismic solution and an existing open-source postseismic model, demonstrating good agreement for all fault geometries tested. Due to the inclusion of self-gravity the model has the potential for predicting deformation in response to multiple sources of stress change, for example, changing ice thickness in tectonically active regions.

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