scholarly journals Implementation of a damage model in a finite element program for computation of structures under dynamic loading

2015 ◽  
Vol 10 (35) ◽  
pp. 278-284
Author(s):  
Nasserdine Oudni ◽  
Youcef Bouafia
Keyword(s):  
Finite Element ◽  
Dynamic Loading ◽  
Damage Model ◽  
Finite Element Program ◽  
Element Program

A MULTIPHASE ANALYSIS FOR ENVIRONMENTAL IMPACT ASSESSMENT WITH θ-STOCK FINITE ELEMENT PROGRAM

2010 ◽  
Vol 02 (01n02) ◽  
pp. 23-68 ◽  
Author(s):  
B. GATMIRI ◽  
S. HEMMATI ◽  
C. ARSON ◽  
E. AMIRZEHNI
Keyword(s):  
Finite Element ◽  
Thermal Loading ◽  
Damage Model ◽  
Degree Of Saturation ◽  
State Variables ◽  
Field Equations ◽  
Finite Element Program ◽  
Independent State ◽  
Brittle Rocks ◽  
Element Program

In the THM modeling of multiphase medium, the coupling effects of skeleton, suction, and temperature have been integrated via the concept of state surfaces of void ratio and degree of saturation. Based on proposed formulation, a fully coupled numerical model for the behavior of soil deformation, water flow, air flow, heat flow in unsaturated soil has been developed and integrated in a finite element code θ-Stock by the first author. This program is conceived with this idea that it will be able to analyze the response of a soil in different states of humidity to mechanical, thermal loading, and also damage phenomena. Damage model is dedicated to unsaturated brittle rocks. It mixes phenomenological and micromechanical concepts and is formulated based on the use of independent state variables. The expression of the liquid permeability is modified in order to represent the influence of fracturing on interstitial fluid flows. The final matrix form of established field equations of the proposed model for unsaturated case has been encoded for this particular purpose, in a finite element program which had been developed for dry and saturated soils previously.

scholarly journals The impact of drilling and slitting construction on damage field: evolution characteristics in low-permeability coal seam

2021 ◽  
Vol 37 ◽  
pp. 205-215
Author(s):  
Heng Chen ◽  
Hongmei Cheng ◽  
Aibin Xu ◽  
Yi Xue ◽  
Weihong Peng
Keyword(s):  
Finite Element ◽  
Rock Mass ◽  
Damage Mechanics ◽  
Effective Strain ◽  
Secondary Development ◽  
Distribution Area ◽  
Finite Element Program ◽  
Element Program ◽  
Mining Face ◽  
The Impact

ABSTRACT The fracture field of coal and rock mass is the main channel for gas migration and accumulation. Exploring the evolution law of fracture field of coal and rock mass under the condition of drilling and slitting construction has important theoretical significance for guiding efficient gas drainage. The generation and evolution process of coal and rock fissures is also the development and accumulation process of its damage. Therefore, based on damage mechanics and finite element theory, the mathematical model is established. The damage variable of coal mass is defined by effective strain, the elastoplastic damage constitutive equation is established and the secondary development of finite element program is completed by FORTRAN language. Using this program, the numerical simulation of drilling and slitting construction of the 15-14120 mining face of Pingdingshan No. 8 Mine is carried out, and the effects of different single borehole diameters, different kerf widths and different kerf heights on the distribution area of surrounding coal fracture field and the degree of damage are studied quantitatively. These provide a theoretical basis for the reasonable determination of the slitting and drilling arrangement parameters at the engineering site.

Finite Element Analysis on the Deformation of Energy-Saving Wire-Mesh Frame Wallboard

2014 ◽  
Vol 501-504 ◽  
pp. 731-735
Author(s):  
Li Zhang ◽  
Kang Li
Keyword(s):  
Finite Element ◽  
Energy Saving ◽  
Theoretical Basis ◽  
Steel Wire ◽  
Wire Mesh ◽  
Design Parameters ◽  
Element Analysis ◽  
Finite Element Program ◽  
Element Program ◽  
Influence Degree

This paper analyzes the influence degree of related design parameters of wire-mesh frame wallboard on deformation through finite element program, providing theoretical basis for the design and test of steel wire rack energy-saving wallboard.

Transferability of the Gurson Damage Model Parameters with Charpy and Tensile Tests with Different Constrain Level

2009 ◽  
Vol 65 ◽  
pp. 19-31
Author(s):  
Ruben Cuamatzi-Melendez ◽  
J.R. Yates
Keyword(s):  
Strain Rate ◽  
Damage Model ◽  
Rolling Direction ◽  
Fracture Initiation ◽  
Tensile Tests ◽  
Model Parameters ◽  
Gurson Model ◽  
Finite Element Program ◽  
Element Program ◽  
Gurson's Model

Little work has been published concerning the transferability of Gurson’s ductile damage model parameters in specimens tested at different strain rates and in the rolling direction of a Grade A ship plate steel. In order to investigate the transferability of the damage model parameters of Gurson’s model, tensile specimens with different constraint level and impact Charpy specimens were simulated to investigate the effect of the strain rate on the damage model parameters of Gurson model. The simulations were performed with the finite element program ABAQUS Explicit [1]. ABAQUS Explicit is ideally suited for the solution of complex nonlinear dynamic and quasi–static problems [2], especially those involving impact and other highly discontinuous events. ABAQUS Explicit supports not only stress–displacement analyses but also fully coupled transient dynamic temperature, displacement, acoustic and coupled acoustic–structural analyses. This makes the program very suitable for modelling fracture initiation and propagation. In ABAQUS Explicit, the element deletion technique is provided, so the damaged or dead elements are removed from the analysis once the failure criterion is locally reached. This simulates crack growth through the microstructure. It was found that the variation of the strain rate affects slightly the value of the damage model parameters of Gurson model.

scholarly journals Numerical Analyses of Earthquake Induced Liquefaction and Deformation Behaviour of an Upstream Tailings Dam

2017 ◽  
Vol 2017 ◽  
pp. 1-12 ◽  
Author(s):  
Muhammad Auchar Zardari ◽  
Hans Mattsson ◽  
Sven Knutsson ◽  
Muhammad Shehzad Khalid ◽  
Maria V. S. Ask ◽  
...  
Keyword(s):  
Finite Element ◽  
Seismic Event ◽  
Deformation Behaviour ◽  
Ground Surface ◽  
Tailings Dam ◽  
Limited Extent ◽  
Northern Sweden ◽  
Finite Element Program ◽  
Dynamic Analyses ◽  
Element Program

Much of the seismic activity of northern Sweden consists of micro-earthquakes occurring near postglacial faults. However, larger magnitude earthquakes do occur in Sweden, and earthquake statistics indicate that a magnitude 5 event is likely to occur once every century. This paper presents dynamic analyses of the effects of larger earthquakes on an upstream tailings dam at the Aitik copper mine in northern Sweden. The analyses were performed to evaluate the potential for liquefaction and to assess stability of the dam under two specific earthquakes: a commonly occurring magnitude 3.6 event and a more extreme earthquake of magnitude 5.8. The dynamic analyses were carried out with the finite element program PLAXIS using a recently implemented constitutive model called UBCSAND. The results indicate that the magnitude 5.8 earthquake would likely induce liquefaction in a limited zone located below the ground surface near the embankment dikes. It is interpreted that stability of the dam may not be affected due to the limited extent of the liquefied zone. Both types of earthquakes are predicted to induce tolerable magnitudes of displacements. The results of the postseismic slope stability analysis, performed for a state after a seismic event, suggest that the dam is stable during both the earthquakes.

A preprocessor for the finite element program SAP IV

1981 ◽  
Vol 17 (12) ◽  
pp. 1779-1789
Author(s):  
E. Haugeneder ◽  
W. Prochazka ◽  
P. Tavolato
Keyword(s):  
Finite Element ◽  
Finite Element Program ◽  
Element Program

Abstract 2871: Saddle-Shaped Annuloplasty Reduces Mitral Leaflet Stress: A Real-Time 3D Echocardiographic Study

Circulation ◽  
2008 ◽  
Vol 118 (suppl_18) ◽  
Author(s):  
Aaron S Blom ◽  
Chun Xu ◽  
Liam P Ryan ◽  
Benjamin Jackson ◽  
Landi M Parish ◽  
...  
Keyword(s):  
Finite Element ◽  
Real Time ◽  
Stress Reduction ◽  
Heart Association ◽  
Posterior Leaflet ◽  
Volume Data ◽  
Medical Systems ◽  
Annuloplasty Ring ◽  
Finite Element Program ◽  
Element Program

Objectives: High leaflet and chordal stresses contribute to recurrent mitral regurgitation after repair procedures. We hypothesized that a saddle-shaped annuloplasty ring would reduce leaflet stress compared to a similarly sized flat annuloplasty ring. To test this hypothesis we used a novel 3D echocardiographically-based finite element modeling (FEM) technique for quantifying regional mitral valve stress. Methods: Real-time 3D echocardiography was performed in 8 sheep before and after placement of either a 30mm flat annuloplasty (n=4) or a 30mm saddle-shaped annuloplasty. Full-volume data sets of the MV were obtained using an IE33 platform(Philips Medical Systems, Andover, Massachusetts) and exported to Cardio-View (Tomtec Imaging Systems, Munich, Germany) for image analysis. Individual leaflet data were then interpolated using Matlab (The Mathworks, Natick, Massachusetts). Triangulated leaflet surfaces were extracted and the data imported into a commercial finite element program (ABAQUS/Explicit 6.3, HKS Inc. Pawtucket, RI) to quantify regional stress distributions in all segments (P1, P2, P3 and A1, A2, A3) of the MV. Results: Peak anterior and posterior leaflet stresses after flat annuloplasty placement were 0.20±0.001MPa and 21±0.02MPa. Peak anterior and posterior leaflet stress after saddle-shaped annuloplasty placement was 0.19±0.02MPa and 13±0.01MPa (p<0.05 for the posterior leaflet stresses) Conclusions: Saddle-shaped annuloplasty design results in greater stress reduction in the posterior leaflet than standard flat annuloplasty rings and may, therefore, result in more durable repairs. This research has received full or partial funding support from the American Heart Association, AHA Great Rivers Affiliate (Delaware, Kentucky, Ohio, Pennsylvania & West Virginia).

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