scholarly journals A numerical study on dynamic shear rupture along frictional faults

2015 ◽  
Vol 25 (1) ◽  
pp. 69-86 ◽  
Author(s):  
Dandan Xu ◽  
Zhanli Liu ◽  
Xiaoming Liu ◽  
Zhuo Zhuang
Keyword(s):  
Stress State ◽  
Numerical Study ◽  
Economic Loss ◽  
Path Selection ◽  
Dynamic Shear ◽  
The Finite Element Method ◽  
Dynamic Rupture ◽  
Shear Rupture ◽  
Main Fault ◽  
Rupture Mechanism

The Wenchuan earthquake (Sichuan province, China, 2008) was caused by the dynamic rupture of Longmen Mountain fault. Such catastrophic disaster had led to a huge damage of life as well as major economic loss. The Longmen Mountain fault consisted of three faults with complex geometries, which gathered together as a main fault underground. The dynamic shear ruptures along the faults including bends and branches are frequently observed during earthquakes. In this study, the finite element method (FEM) is adopted to simulate the dynamic ruptures along both straight and branched faults, which are considered as frictional interfaces. A slip-weakening friction law is used to describe the interface behavior along faults. For the straight fault, the effects of pre-stress state and nucleation parameters on the dynamic shear rupture process are investigated; for the branched faults, the effects of pre-stress state and fault geometry on the rupture path selection are presented. The results are used to explain the rupture mechanism of Longmen Mountain fault during the earthquake.

scholarly journals Finite element simulations of dynamic shear rupture experiments and dynamic path selection along kinked and branched faults

2009 ◽  
Vol 114 (B8) ◽  
Author(s):  
Elizabeth L. Templeton ◽  
Aurélie Baudet ◽  
Harsha S. Bhat ◽  
Renata Dmowska ◽  
James R. Rice ◽  
...  
Keyword(s):  
Finite Element ◽  
Path Selection ◽  
Finite Element Simulations ◽  
Dynamic Shear ◽  
Shear Rupture ◽  
Dynamic Path

Fan-Hinged Shear as a Unique Mechanism of Dynamic Shear Ruptures

2016 ◽  
Vol 258 ◽  
pp. 165-168
Author(s):  
Boris Tarasov ◽  
Mikhail Guzev ◽  
Vladimir Sadovskiy ◽  
Alexander Losev
Keyword(s):  
Mathematical Model ◽  
Shear Resistance ◽  
Rupture Propagation ◽  
Dynamic Shear ◽  
Tensile Cracks ◽  
Frictional Strength ◽  
Shear Rupture ◽  
Rupture Mechanism ◽  
Unique Mechanism ◽  
Low Shear

Recently a new fan-hinged shear rupture mechanism has been identified as a unique mechanism of dynamic shear ruptures. In the fan-mechanism, the shear rupture propagation is driven by a fan-shaped rupture head consisting of an echelon of intercrack (domino-like) blocks formed due to the consecutive creation of small tensile cracks in the rupture tip. The fan-structure propagates through the intact material as a wave and has a number of extraordinary features, one of which is extremely low shear resistance of the rupture head (below the frictional strength). Here we present a mathematical model elucidating the principles of this new mechanism. The model will support comprehensive studies of unique features of the discovered phenomenon.

Numerical Study of the Flow Forming Process of AISI 630 Stainless Steel

2011 ◽  
Vol 264-265 ◽  
pp. 24-29 ◽  
Author(s):  
Seyed Mohammad Ebrahimi ◽  
Seyed Ali Asghar Akbari Mousavi ◽  
Mostafa Soltan Bayazidi ◽  
Mohammad Mastoori
Keyword(s):  
Feeding Rate ◽  
Surface Defects ◽  
Numerical Study ◽  
Internal Diameter ◽  
The Finite Element Method ◽  
Forming Process ◽  
Flow Forming ◽  
Cold Forming ◽  
External Variables ◽  
Experimental Process

Flow forming is one of the cold forming process which is used for hollow symmetrical shapes. In this paper, the forward flow forming process is simulated using the finite element method and its results are compared with the experimental process. The variation of thickness of the sample is examined by the ultrasonic tests for the five locations of the tubes. To simulate the process, the ABAQUS explicit is used. The effects of flow forming variables such as the angle of rollers and rate of feeding of rollers, on the external variables such as internal diameter, thickness of tube and roller forces are considered. The study showed that the roller force and surface defects were reduced with low feeding rate and low rollers attack angles. Moreover, the sample internal diameter increased at low feeding rate and low rollers attack angles. The optimum variables for flow forming process were also obtained.

Numerical Study of Corrugated Metal Panels Subjected to Windborne Debris Impacts

2014 ◽  
Vol 626 ◽  
pp. 109-114
Author(s):  
Wen Su Chen ◽  
Hong Hao ◽  
Hao Du
Keyword(s):  
Extreme Event ◽  
Numerical Study ◽  
Numerical Models ◽  
Economic Loss ◽  
Wind Loading ◽  
Windborne Debris ◽  
Study Laboratory ◽  
The Impact ◽  
Metal Panels ◽  
Corrugated Metal

Hurricane, typhoon and cyclone take place more and more often around the world with changing climate. Such nature disasters cause tremendous economic loss and casualty. Various kinds of windborne debris such as compact-like, plate-like and rod-like objects driven by hurricane usually imposes localized impact loading on the structure envelopes such as cladding, wall or roof, etc. The dominant opening in the envelope might cause serious damage to the structures, even collapse. To withstand the impact of such extreme event, the requirements on panel capacity to resist windborne debris impact has been presented in the Australian Wind Loading Code (2011) [1]. Corrugated metal panels are widely used as building envelop. In a previous study, laboratory tests have been carried out to investigate the performance of corrugated metal panels subjected to a 4kg wooden projectile by considering various impact locations, impact velocities and boundary conditions. In this study, numerical models were developed to simulate the responses of the corrugated metal panels subjected to wooden debris impacts by using commercial software LS-DYNA. The predicted data from the numerical simulations were compared with the experimental results. The validated numerical model can be used to conduct intensive numerical simulation to study the failure probabilities of corrugated structural panels subjected to windborne debris impacts.

scholarly journals Modeling of Size Effects in Bending of Perforated Cosserat Plates

2017 ◽  
Vol 2017 ◽  
pp. 1-19 ◽  
Author(s):  
Roman Kvasov ◽  
Lev Steinberg
Keyword(s):  
Finite Element ◽  
Stress Concentration ◽  
Numerical Study ◽  
The Finite Element Method ◽  
Classical Elasticity ◽  
Element Analysis ◽  
Plate Deformation ◽  
The Finite Element Analysis ◽  
Circular Holes ◽  
Different Shapes

This paper presents the numerical study of Cosserat elastic plate deformation based on the parametric theory of Cosserat plates, recently developed by the authors. The numerical results are obtained using the Finite Element Method used to solve the parametric system of 9 kinematic equations. We discuss the existence and uniqueness of the weak solution and the convergence of the proposed FEM. The Finite Element analysis of clamped Cosserat plates of different shapes under different loads is provided. We present the numerical validation of the proposed FEM by estimating the order of convergence, when comparing the main kinematic variables with an analytical solution. We also consider the numerical analysis of plates with circular holes. We show that the stress concentration factor around the hole is less than the classical value, and smaller holes exhibit less stress concentration as would be expected on the basis of the classical elasticity.

Theoretical Study on Recombination Efficiency at S-DPVBi/Alq3 Interface in OLED

2012 ◽  
Vol 629 ◽  
pp. 44-48
Author(s):  
Young Wook Hwang ◽  
Kwang Sik Kim ◽  
Tae Young Won
Keyword(s):  
Indium Tin Oxide ◽  
Numerical Study ◽  
Organic Light Emitting Diodes ◽  
Transport Layer ◽  
Electron Transport Layer ◽  
The Finite Element Method ◽  
Light Emitting ◽  
Recombination Efficiency ◽  
Interface Barrier ◽  
Recombination Kinetics

In this paper, we report our numerical study on the electrical-optical properties of the organic light emitting diodes (OLEDs) devices with n-doped layer, which is inserted in an effort to reduce the interface barrier between the cathode and the ETL(electron transport layer). In order to anlayze the electrical and optical characteristics such as the transport behavior of carriers, recombination kinetics, and emission property, we undertake the finite element method (FEM) in OLEDs. Our model includes Poisson’s equation, continuity equation to account for behavior of electrons and holes and the exciton continuity/transfer equation to account for recombination of carriers. We employ the multilayer structure that consists of indium tin oxide (ITO); 2, 2’, 7, 7’ –tetrakis (N, N-diphenylamine) - 9, 9’- spirobi-fluorene (S-TAD); 4, 4’- bis (2,2’- diphenylvinyl) - 1,1’- spirobiphenyl (S-DPVBi); tris (8-quinolinolato) aluminium (Alq3); calsium(Ca).

Residual strength of underground structures in service

2016 ◽  
Vol 53 (6) ◽  
pp. 988-999 ◽  
Author(s):  
Taous Kamel ◽  
Ali Limam ◽  
Claire Silvani
Keyword(s):  
Stress State ◽  
Residual Strength ◽  
Underground Structure ◽  
Numerical Approach ◽  
The Finite Element Method ◽  
Underground Structures ◽  
Weathering Processes ◽  
Working Face ◽  
Metro Tunnel ◽  
Loss Of Strength

Old tunnels suffer from deterioration and it is necessary to assess their residual strength to properly organize their repair and strengthen them. The stress state of underground structures evolves over time, firstly because of the advancement of the working face during construction, then due to gradual changes in soil properties and mechanical properties of materials composing the infrastructures, such as reduction of cohesion, loss of strength and (or) stiffness, etc. These changes are caused by combined actions such as creep and (or) weathering processes as well as the appearance of cracks that induce redistribution of stresses and therefore strains. This study investigates tunnels and galleries of the Paris underground. Macromodeling based on the finite element method allows consideration of different scenarios of tunnel-lining deterioration, specifically at the extrados of the galleries or tunnels. To understand changes in the stress state, and also damage occurrence and associated redistributions (stress and strain), it is necessary to model the delayed deformations. To model the infrastructure behavior, a time-dependency approach has been chosen. This approach can quantify the damage and predict the residual strength of this type of underground structure. An elastic–viscoplastic constitutive model with strain-softening is used to reproduce the appearance of the degraded zones and their behavior. The results obtained with the numerical approach reproduce Paris metro tunnel behavior, corroborate geoendoscopy results, clarify their interpretation, and improve the management of infrastructure repairs.

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