scholarly journals Hypoplastic Interface Model considering Plane Strain Condition and Surface Roughness

2021 ◽  
Vol 2021 ◽  
pp. 1-13
Author(s):  
Yong-Gwang Jong ◽  
Yang Liu ◽  
Zixuan Chen ◽  
Pieride Mabe Fogang
Keyword(s):  
Experimental Data ◽  
Mechanical Properties ◽  
Plane Strain ◽  
Contact Surface ◽  
Soil Structure ◽  
Dimensional Space ◽  
Three Dimensional ◽  
Interface Problem ◽  
Hypoplastic Model ◽  
Improved Model

The soil-structure interface problem is an important part of soil-structure interaction research. These problems are mostly three-dimensional space problems, which is more complex to solve. In this paper, reduced stress and strain rate vectors are incorporated into the explicitly granular hypoplastic model by considering the plane strain state precisely. In addition, considering the important influence of roughness on the mechanical properties of contact surface, an improved hypoplastic model is established by incorporating the influence of roughness into the hypoplastic model, and the applicability of the new improved model is validated by comparing with the simulation results of the Mohr–Coulomb model, the explicitly granular hypoplastic models, and the experimental data. The results indicate that the improved model can be utilized to reflect the nonlinearity of the mechanical properties of the contact surface, which is in good agreement with the experimental data.

An efficient three-dimensional soil–structure interaction model for analysis of earth retaining structures

1992 ◽  
Vol 29 (4) ◽  
pp. 529-538 ◽  
Author(s):  
H. H. Vaziri ◽  
V. M. Troughton
Keyword(s):  
Soil Structure ◽  
Dimensional Space ◽  
Retaining Wall ◽  
Three Dimensional ◽  
Soil Structure Interaction ◽  
Predictive Tool ◽  
Soil System ◽  
Soil Medium ◽  
Structure Interaction ◽  
Stress Changes

Using the integrated form of Mindlin's equations that relate the stress and displacement field anywhere within a three-dimensional space in an isotropic and elastic soil medium, a boundary-element-based numerical model is presented for analyzing soil–structure interaction problems involving excavations around embedded structures. The solution procedure involves combining the stiffness matrix of the wall and soil system and computing the displacements from a knowledge of the stress changes due to excavation. An interative approach is adopted to apply the correcting forces at locations that reach active or passive states, thus resulting in correct displacements for plastic conditions that cannot be accounted for by the Mindlin's elastic solutions. The model is shown to provide matching results against a finite-element model under plane-strain conditions. Application of the proposed model within the context of a practical project has demonstrated its role both as a predictive tool and as a theoretical model for performing sensitivity analysis and establishing practical guidelines to control magnitude and mode of wall deflections, which are important design considerations in excavations close to movement-sensitive structures. Key words : numerical modelling, elasticity, three-dimensional effects, soil–structure interaction, retaining wall, excavation.

scholarly journals Design and construction of a continuous impregnation apparatus of woven fibres, using non-meshing double-sinusoidal toothed rollers

2020 ◽  
Vol 317 ◽  
pp. 01006
Author(s):  
G. Vasileiou ◽  
C. Vakouftsis ◽  
N. Rogkas ◽  
S. Tsolakis ◽  
P. Zalimidis ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Theoretical Calculations ◽  
Dimensional Space ◽  
Continuous Production ◽  
Three Dimensional ◽  
Industrial Applications ◽  
Three Dimensions ◽  
Main Challenge ◽  
Complete Failure ◽  
As Stress

Resin-impregnated fibres are extensively used in a variety of industrial applications as is demonstrated in the literature. Resin-fibre impregnation techniques are used in order to create homogeneous macro – materials and to take full advantage of the mechanical properties of the fibrous reinforcement (i.e. carbon, glass, organic or ceramic fibres). However, achieving highly impregnated fibres is proven quite challenging especially in continuous production techniques that are required for large production rates. The main challenge lies in achieving complete impregnation of the tightly arranged fibres mainly referring to the formed yarns containing multiple fibres, sometimes even twisted. This results in partially impregnated materials containing cavities that tend to exhibit inferior mechanical properties compared to the theoretical calculations, which assume fully impregnated materials. These cavities often lead to crack generation, acting as stress concentration sites, resulting in complete failure of the material at macro-level. In this paper a novel technique for continuous production of fully impregnated woven fibres is presented using non – meshing, co – rotating rollers. A laboratory-scale apparatus is designed and described thoroughly in the context of this work. The method resembles pultrusion in the sense that a reinforcement plain fibre mesh (glass) is co–processed with the liquid resin through a pair of co–rotating toothed rollers to produce a continuously reinforced 3D tape. The surface of the rollers is produced from a double-sinusoidal toothed surface (rack) using the Theory of Gearing in three-dimensions, which imposes significant differential sliding of the fibres without differential tension and facilitates fibre wetting. The geometry of the rollers is calculated not to damage the unprocessed fibres, while facilitating local widespreading of the stranded fibres in the three – dimensional space leading to the resin being able to fully penetrate the reinforcing fibre material.

SPONTANEOUS FISSION HALF LIVES OF Z = 112 ISOTOPES

2008 ◽  
Vol 17 (01) ◽  
pp. 253-258 ◽  
Author(s):  
Z. ŁOJEWSKI ◽  
A. BARAN
Keyword(s):  
Experimental Data ◽  
Spontaneous Fission ◽  
Dimensional Space ◽  
Three Dimensional ◽  
Minimization Method ◽  
Macroscopic Models ◽  
Deformation Parameters ◽  
State Dependent ◽  
Three Dimensional Space

Barriers and spontaneous fission half lives of superheavy isotopes of Z = 112 (N = 150–190) nucleus are calculated using state dependent δ-pairing and both BCS or Lipkin-Nogami (LN) approach. Four different models of macroscopic part of Strutinsky energy are probed. Results for different macroscopic models combined with δ+ LN approach give the half lives well compared to experimental data. The calculations are performed in three dimensional space of deformation parameters β = {β2, β4, β6}. The probability of spontaneous fission has been obtained by dynamical action minimization method.

Numerical Simulation and Experimental Research on Fatigue Strength of the Injector Guide Pillar under Complex Loads

2010 ◽  
Vol 118-120 ◽  
pp. 196-200
Author(s):  
Jin Guo Li ◽  
Xiao Gui Wang ◽  
Zeng Liang Gao
Keyword(s):  
Experimental Data ◽  
Mechanical Properties ◽  
Numerical Simulation ◽  
Experimental Study ◽  
Fatigue Life ◽  
Fatigue Strength ◽  
Numerical Analysis ◽  
Experimental Research ◽  
Contact Surface ◽  
Electronic Measurement

Under the complex loads, the injector guide pillar (IGP) used in injection machine was failure only after 1.5-year-service. In order to determine the cause of the fracture, the numerical simulation technology was applied to analyze the mechanical properties of the IGP. The contact between the mating surfaces of the clamping mechanism was modeled; nonlinear multi-region contact of surface-surface was applied to establish the contact model of FEA. The constraint of tie was used for modeling thread joint. The simulated results indicated that the smaller area of contact surface, the higher value of stress in the neck of IGP. Electronic measurement was also used to check the results of stress in IGP obtained by FEA. It was found that the experimental data agreed well with simulated results. Based on the numerical analysis and experimental study, the structure of IGP was improved by adopting a smoother double-round neck. The fatigue life of the improved structure was longer than that of the original machine.

Stresses in Nonhomogeneous Cylindrically Anisotropic Elastic Cylinder

1977 ◽  
Vol 44 (4) ◽  
pp. 774-776
Author(s):  
Subhas Chandra Roy
Keyword(s):  
Mechanical Properties ◽  
Plane Strain ◽  
Linear Theory ◽  
Radial Displacement ◽  
Three Dimensional ◽  
Elastic Cylinder ◽  
Theory Of Elasticity ◽  
Cylindrical Anisotropy ◽  
Anisotropic Elastic ◽  
Cylindrically Anisotropic

The object of this Note is to determine the radial displacement and relevant stresses in a cylinder (plane strain) on the basis of three-dimensional linear theory of elasticity. The material of the structure is orthotropic with cylindrical anisotropy and, in addition, is continuously inhomogeneous with mechanical properties varying along the radius.

SOUND SOURCE LOCALIZATION IN THREE-DIMENSIONAL SPACE IN REAL TIME WITH REDUNDANCY CHECKS

2012 ◽  
Vol 20 (01) ◽  
pp. 1250007 ◽  
Author(s):  
NA ZHU ◽  
SEAN F. WU
Keyword(s):  
Source Localization ◽  
Signal To Noise Ratio ◽  
Dimensional Space ◽  
Broad Band ◽  
Three Dimensional ◽  
Sound Sources ◽  
Detection Range ◽  
Basic Model ◽  
Improved Model ◽  
Three Dimensional Space

Triangulation is commonly used for source localization and most triangulation applications are based on intersection of the bearing direction to locate a source on a two-dimensional plane. In this paper, two new mathematical models (a basic model and an improved one) that expands the traditional triangulation concept to three-dimensional space are developed to locate multiple incoherent sound sources. The basic model uses four microphones and concentrates on solving a set of three quadratic equations simultaneously. The improved model requires more than four microphones and uses the solution from the basic model, as well as analyzing the intersection of bearing angles. Redundancy checks on the time differences of arrival are added to further reduce the source localization error in the improved model. Moreover, the input data are pre-processed and de-noised through filtering and windowing to enhance the effective signal to noise ratio. Various sound sources are tested, including transient, impulsive, continuous, broad-band, and narrow-band sounds. Numerical simulations and experimental validation using the real world sound sources are conducted. The impacts of the source direction/source detection range on the accuracy of source localization results are examined and discussed.

A Mathematical Model for the Morphology of the Pulmonary Acinus

1996 ◽  
Vol 118 (2) ◽  
pp. 210-215 ◽  
Author(s):  
E. Denny ◽  
R. C. Schroter
Keyword(s):  
Experimental Data ◽  
Mathematical Model ◽  
Dimensional Space ◽  
Three Dimensional ◽  
Computational Method ◽  
Published Data ◽  
Space Filling ◽  
Pulmonary Acinus ◽  
Path Lengths ◽  
Three Dimensional Space

A computational method is proposed for the construction of a three-dimensional space-filling model of an acinar ventilatory unit. Its geometry consists of truncated octahedra arranged in a cuboidal block. The ducts and alveoli are formed by opening specific common faces between polyhedra. The branching structure is automatically computed using algorithms solely to maximise the number of alveoli and minimise the average path lengths; it is not formed with reference to published experimental data. Properties of the model such as the total alveolar and ductal volumes, the distribution of individual path lengths to the alveolar sacs, and the average number of ducts per generation are calculated. The predicted morphology of the model compares well with published data for rat lungs.

scholarly journals Finite Element Simulation of Multipass Welding: Full Three-Dimensional Versus Generalized Plane Strain or Axisymmetric Models

2005 ◽  
Vol 40 (6) ◽  
pp. 587-597 ◽  
Author(s):  
W Jiang ◽  
K Yahiaoui ◽  
F R Hall ◽  
T Laoui
Keyword(s):  
Experimental Data ◽  
Finite Element ◽  
Plane Strain ◽  
Three Dimensional ◽  
Welding Process ◽  
Fe Model ◽  
Multipass Welding ◽  
Numerical Predictions ◽  
Material Deposition ◽  
Generalized Plane Strain

A full three-dimensional (3D) thermo-mechanical finite element (FE) model has been developed to simulate the step-by-step multipass welding process. Non-linearities associated with welding, such as a moving heat source, material deposition, temperature-dependent material properties, latent heat, and large deformations, were taken into account. The model was applied to multipass butt-welded mild steel plate and girth butt-welded stainless steel pipe for validation. The simulation results were compared with independently obtained experimental data and numerical predictions from two-dimensional (2D) generalized plane strain and axisymmetric models. Good agreements between the 3D predictions and experimental data have been obtained. The computational model has the potential to be applied to multipass welded complex geometries for residual stress prediction.

Three Dimensional structure and organization of diploid chromosomes by optical section microscopy

1987 ◽  
Vol 45 ◽  
pp. 633-635
Author(s):  
David A. Agard ◽  
Yasushi Hiraoka ◽  
John W. Sedat
Keyword(s):  
Dimensional Space ◽  
Three Dimensional ◽  
Developmental State ◽  
Mitotic Cell ◽  
Biological Properties ◽  
Dimensional Structure ◽  
Specific Gene ◽  
Three Dimensional Structure ◽  
Complementary Techniques ◽  
Dynamic Structures

In an effort to understand the complex relationship between structure and biological function within the nucleus, we have embarked on a program to examine the three-dimensional structure and organization of Drosophila melanogaster embryonic chromosomes. Our overall goal is to determine how DNA and proteins are organized into complex and highly dynamic structures (chromosomes) and how these chromosomes are arranged in three dimensional space within the cell nucleus. Futher, we hope to be able to correlate structual data with such fundamental biological properties as stage in the mitotic cell cycle, developmental state and transcription at specific gene loci.Towards this end, we have been developing methodologies for the three-dimensional analysis of non-crystalline biological specimens using optical and electron microscopy. We feel that the combination of these two complementary techniques allows an unprecedented look at the structural organization of cellular components ranging in size from 100A to 100 microns.

Diffraction contrast of dislocations in icosahedral quasicrystals

1990 ◽  
Vol 48 (4) ◽  
pp. 454-455
Author(s):  
K. Urban ◽  
Z. Zhang ◽  
M. Wollgarten ◽  
D. Gratias
Keyword(s):  
Dimensional Space ◽  
Three Dimensional ◽  
Complete Characterization ◽  
Extinction Condition ◽  
Burgers Vector ◽  
Diffraction Contrast ◽  
Lattice Geometry ◽  
Reference Space ◽  
Icosahedral Quasicrystals ◽  
The One

Recently dislocations have been observed by electron microscopy in the icosahedral quasicrystalline (IQ) phase of Al65Cu20Fe15. These dislocations exhibit diffraction contrast similar to that known for dislocations in conventional crystals. The contrast becomes extinct for certain diffraction vectors g. In the following the basis of electron diffraction contrast of dislocations in the IQ phase is described. Taking account of the six-dimensional nature of the Burgers vector a “strong” and a “weak” extinction condition are found.Dislocations in quasicrystals canot be described on the basis of simple shear or insertion of a lattice plane only. In order to achieve a complete characterization of these dislocations it is advantageous to make use of the one to one correspondence of the lattice geometry in our three-dimensional space (R3) and that in the six-dimensional reference space (R6) where full periodicity is recovered . Therefore the contrast extinction condition has to be written as gpbp + gobo = 0 (1). The diffraction vector g and the Burgers vector b decompose into two vectors gp, bp and go, bo in, respectively, the physical and the orthogonal three-dimensional sub-spaces of R6.

Sign in / Sign up

Export Citation Format

Share Document