scholarly journals Numerical Study of Stresses around Holes Drilled and Filled by Expansive Cement: Case of Isotropic Linear Elastic Block of Rock

2018 ◽  
Vol 2018 ◽  
pp. 1-14
Author(s):  
Mambou Ngueyep Luc Leroy ◽  
Gael Nkenwoum Chebou
Keyword(s):  
Finite Element ◽  
Elastic Properties ◽  
Numerical Study ◽  
Hole Diameter ◽  
Finite Element Code ◽  
Normal Stresses ◽  
Linear Elastic ◽  
Diameter Hole ◽  
Essential Problem ◽  
Expansive Cement

This work dealt with an essential problem of fragmentation of rocks with expansive cement. The redistribution and magnitude of stresses and displacement generated around holes were done by using Ansys Inc. Code which is based on finite element code. Blocks of rock with one hole, two holes, and nine holes drilled in square mesh and staggered mesh have been considered. Numerical results reveal that many factors can influence the mechanism of fragmentation of a rock by using expansive cement: hole diameter, hole spacing, panel mesh, expansive pressure applied, and the elastic properties of the massif. Stresses and displacements generated globally decrease when spacing holes increase. Normal stresses allow a better stress interaction between holes in the case of square mesh disposition. Staggered mesh disposition generates higher stresses than the square mesh disposition. But the square mesh disposition can be useful for controlled fragmentation in order to obtain block of rock with square geometry. For each expansive cement and rock, there exist suitable range of diameter and spacing hole which can generate high stresses for breaking the rock.

scholarly journals Finite Element Analysis Of Airfield Flexible Pavement

2014 ◽  
Vol 60 (3) ◽  
pp. 323-334 ◽  
Author(s):  
G. Leonardi
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
3D Model ◽  
Numerical Study ◽  
Permanent Deformation ◽  
Flexible Pavement ◽  
Finite Element Code ◽  
Element Analysis ◽  
Pavement Response ◽  
The Impact

Abstract The paper presents a numerical study of an aircraft wheel impacting on a flexible landing surface. The proposed 3D model simulates the behaviour of flexible runway pavement during the landing phase. This model was implemented in a finite element code in order to investigate the impact of repeated cycles of loads on pavement response. In the model, a multi-layer pavement structure was considered. In addition, the asphalt layer (HMA) was assumed to follow a viscoelastoplastic behaviour. The results demonstrate the capability of the model in predicting the permanent deformation distribution in the asphalt layer.

Part-Elliptical Cracks Emanating From Open and Loaded Holes in Plates

1979 ◽  
Vol 101 (1) ◽  
pp. 12-17 ◽  
Author(s):  
T. E. Kullgren ◽  
F. W. Smith
Keyword(s):  
Finite Element ◽  
Stress Intensity ◽  
Stress Intensity Factors ◽  
Crack Opening ◽  
Plate Thickness ◽  
Hole Diameter ◽  
Elastic Analysis ◽  
Intensity Factors ◽  
Linear Elastic ◽  
Elliptical Cracks

A linear elastic analysis using the finite element-alternating method is conducted for problems of single semi-elliptical and double quarter-elliptical cracks near fastener holes. Mode-one stress intensity factors are presented along the crack periphery for cases of open and loaded holes and crack opening displacements are calculated. Results are shown for a variety of crack geometries and loading conditions and for two ratios of hole diameter to plate thickness.

scholarly journals Numerical modelling of large landslides stability and runout

2003 ◽  
Vol 3 (6) ◽  
pp. 523-538 ◽  
Author(s):  
G. B. Crosta ◽  
S. Imposimato ◽  
D. G. Roddeman
Keyword(s):  
Finite Element ◽  
Mass Movements ◽  
Large Displacements ◽  
Finite Element Code ◽  
Development Models ◽  
Linear Elastic ◽  
Elastic Part ◽  
Flow Development ◽  
Elasto Plasticity ◽  
Landslide Runout

Abstract. Modelling of flow-like landslides is one of the possible approaches that can be used to simulate landslide instability and flow development. Models based on continuum mechanics and associated with a versatile rheological model are usually preferred to predict landslide runout and relevant parameters. A different approach has been used in this research. We have developed a 2-D/3-D finite element code to analyse slope stability and to model runout of mass movements characterised by very large displacements. The idea was to be able to use different material laws already known, tested and verified for granular materials. The implemented materials laws include classical elasto-plasticity, with a linear elastic part and different applicable yield surfaces with associated and non-associated flow rules. The application of Finite Element methods to model landslide run-out, contrasts previous research where typically depth-averaged equivalent-fluid approaches were adopted. The code has been applied to the simulation of large rock avalanches and rapid dry flows in different materials and under different geological and geomorphological conditions.

Quarter Elliptical Cracks Emanating From Holes in Plates

1978 ◽  
Vol 100 (2) ◽  
pp. 144-149 ◽  
Author(s):  
T. E. Kullgren ◽  
F. W. Smith ◽  
G. P. Ganong
Keyword(s):  
Finite Element ◽  
Analytic Solution ◽  
Plate Thickness ◽  
Hole Diameter ◽  
Solution Technique ◽  
Element Solution ◽  
Intensity Factors ◽  
Flat Plates ◽  
Linear Elastic ◽  
Elliptical Cracks

The finite element-alternating method, a linear elastic solution technique, is refined and applied to problems of quarter-elliptical cracks in irregular bodies. The method involves the iterative superposition of a finite element solution for stresses in an unflawed body and an analytic solution for stresses in an infinite solid containing a flat elliptical crack. Mode-one stress intensity factors are presented along the periphery of quarter-elliptical cracks emanating from open fastener holes in flat plates. Results are shown for a variety of crack geometries and two hole-diameter to plate-thickness ratios. Comparisons are made with experimental results of other authors.

scholarly journals Numerical Investigation of Blast Performance of Plate-Reinforced Moment-Resisting Connection Using Large Concrete Filled Tubular Section

2020 ◽  
Vol 10 (11) ◽  
pp. 3700
Author(s):  
Jinwon Shin ◽  
Seong-Hoon Hwang ◽  
Jinkyu Kim
Keyword(s):  
Finite Element ◽  
Failure Modes ◽  
Numerical Study ◽  
Blast Resistance ◽  
Finite Element Code ◽  
Moment Connection ◽  
Moment Resisting ◽  
Cft Column ◽  
Improvised Explosive ◽  
Blast Performance

This paper presents a numerical study to investigate the blast performance of a plate-reinforced moment-resisting connection using a large concrete filled tubular (CFT) column with dimensions of 1000 × 1000 mm and a thickness of 40 mm. A steel H-section with dimensions of 700 × 300 × 13 × 24 mm is used for beam. The plate-reinforced large CFT connection is analyzed numerically using a finite element code to evaluate its blast resistance. The methodology of modeling the connection is validated based on a past experimental study and verified using an alternate finite element code. Five improvised explosive devices (IED) are considered as blast loadings. The blast resistance of the proposed connection against the IED attacks is investigated based on the design criteria specified in the U.S. government document, UFC 3-340-02, and in comparison to that of a widely used through-diaphragm moment connection. Local failure modes in the vicinity of the connections are also examined. Recommendation is provided for design practice.

Application of the finite element method to prediction of onset of delamination growth

2002 ◽  
Vol 55 (2) ◽  
pp. 89-106 ◽  
Author(s):  
Antonio Miravete ◽  
Miguel A Jime´nez
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Numerical Study ◽  
Dissimilar Materials ◽  
3D Analysis ◽  
The Finite Element Method ◽  
Delamination Growth ◽  
Linear Elastic ◽  
Elastic Fracture ◽  
Element Method

The present article is concerned with the application of the finite element method to the analysis of the onset of delamination growth in composites by means of the virtual crack closure technique (VCCT). The article reviews first the application of linear elastic fracture mechanics (LEFM) to the analysis of delamination, as well as the reasons why the VCC technique is the standard method of combining LEFM and the finite element method to predict onset of delamination growth. The article also reviews the different solutions proposed in the literature to deal with the oscillatory singularity associated with a crack between two dissimilar materials (as is the case for a delamination) and the practical details of the VCCT application in a general 3D analysis. Finally, the results of a numerical study of the mixed mode bending (MMB) interlaminar fracture test are shown. The study applies the concepts reviewed along the rest of this article and presents some practical recommendations for the analysis of a delamination front using finite elements. This review article includes 77 references.

scholarly journals Finite Element Modelling and Mechanical Characterization of Graphyne

2016 ◽  
Vol 2016 ◽  
pp. 1-15 ◽  
Author(s):  
Ricardo Couto ◽  
Nuno Silvestre
Keyword(s):  
Finite Element ◽  
Elastic Properties ◽  
Density Functional ◽  
Computational Models ◽  
Mechanical Characterization ◽  
Computational Simulation ◽  
Md Simulations ◽  
Small Strain ◽  
Fe Model ◽  
Linear Elastic

Graphyne is an allotrope of carbon with excellent mechanical, electrical, and optical properties. The scientific community has been increasingly interested in its characterization and computational simulation, using molecular dynamics (MD) simulations and density functional theory (DFT). The present work presents, for the first time (to the authors’ knowledge), a finite element (FE) model to evaluate the elastic properties of graphyne. After presenting a brief literature review on the latest developments of graphyne and its mechanical characterization through computational methods, the FE model of graphyne sheet is presented in detail and the calculation of its elastic properties described. The linear elastic properties (Young’s modulus, Poisson’s ratio, bulk modulus, and shear modulus) obtained from the proposed FE models are in general agreement with those previously obtained by other authors using more complex computational models (MD and DFT). The influence of van der Waals (vdW) interatomic forces on the linear elastic properties of planar graphyne is negligible and can be disregarded if small strain hypothesis is adopted. The FE models also show that graphyne exhibits marginal orthotropic behavior, that is, “quasi-isotropic” behavior, a fact that agrees with the conclusions reported by other researchers.

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