scholarly journals Nonlinear Analysis of the Thaw Settlement in Ice-Rich Embankments

2021 ◽  
Vol 2021 ◽  
pp. 1-9
Author(s):  
Gaosheng Yang ◽  
Peipei Chen ◽  
Guoqing Cai
Keyword(s):  
Numerical Simulation ◽  
Pore Water ◽  
Nonlinear Theory ◽  
Large Strain ◽  
Interactive Effects ◽  
Thaw Consolidation ◽  
Nonlinear Stress ◽  
Operation Period ◽  
Thaw Settlement ◽  
The Law

In this paper, the law of ice-rich permafrost embankment thaw consolidation is studied based on three-dimensional nonlinear large strain thaw consolidation theory. To avoid problems associated with numerical simulation efficiency and stability when a nonlinear stress-strain relationship is employed, a segment interpolation function is used to implement the nonlinear relationship between the compression modulus and the void ratio, and the corresponding simulation strategy is proposed. Through a comparison of the monitoring and calculated results, it is indicated that the calculation accuracy on ice-rich embankment thaw settlement can be notably improved after nonlinear theory is implemented with the proposed numerical simulation method. A further analysis of the calculated results indicates that the interactive effects between the thermal and mechanical fields can be more reasonably described by nonlinear theory than by linear theory. It is also determined that the postthaw pore water in the shallow embankment dissipates in the early operation period, while in the following long operation period, the development of the permafrost embankment thaw settlement is mainly due to the dissipation of newly postthaw pore water at the thaw depth or the permafrost table. This is one of the main differences in the law of permafrost embankment thaw settlement compared with that of unfrozen embankments.

Continuum Description of the Time- and Strain-Dependent Poisson’s Ratio of Ligament Under Finite Deformation

2013 ◽  
Author(s):  
Aaron M. Swedberg ◽  
Shawn P. Reese ◽  
Steve A. Maas ◽  
Benjamin J. Ellis ◽  
Jeffrey A. Weiss
Keyword(s):  
Large Scale ◽  
Mechanical Response ◽  
Tensile Deformation ◽  
Large Strain ◽  
Fiber Direction ◽  
Strain Behavior ◽  
Nonlinear Stress ◽  
Poisson's Ratios ◽  
Poisson’S Ratios ◽  
Strain Dependent

Ligament volumetric behavior controls fluid and thus nutrient movement as well as the mechanical response of the tissue to applied loads. The reported Poisson’s ratios for tendon and ligament subjected to tensile deformation loading along the fiber direction are large, ranging from 0.8 ± 0.3 in rat tail tendon fascicles [1] to 2.98 ± 2.59 in bovine flexor tendon [2]. These Poisson’s ratios are indicative of volume loss and thus fluid exudation [3,4]. We have developed micromechanical finite element models that can reproduce both the characteristic nonlinear stress-strain behavior and large, strain-dependent Poisson’s ratios seen in tendons and ligaments [5], but these models are computationally expensive and unfeasible for large scale, whole joint models. The objectives of this research were to develop an anisotropic, continuum based constitutive model for ligaments and tendons that can describe strain-dependent Poisson’s ratios much larger than the isotropic limit of 0.5. Further, we sought to demonstrate the ability of the model to describe experimental data, and to show that the model can be combined with biphasic theory to describe the rate- and time-dependent behavior of ligament and tendon.

Test Analysis of MSD Crack Propagation Structure in 2524-T3 Aluminium Alloy

2014 ◽  
Vol 574 ◽  
pp. 386-390
Author(s):  
Jian Ping Zhang ◽  
Xiao Ling Zheng
Keyword(s):  
Numerical Simulation ◽  
Crack Propagation ◽  
Aluminium Alloy ◽  
Crack Growth ◽  
Growth Parameters ◽  
Interactive Effects ◽  
Aviation Industry ◽  
Test Analysis ◽  
Finite Element Software ◽  
Fast Prediction

The MSD phenomenon is an active research topic of the academic and the aviation industry. This paper puts emphasis on the multi-crack propagation with interactive effects of MSD structure in 2524-T3 aluminium alloy. Material tests were accomplished for the crack growth parameters. The multi-crack propagation tests were conducted on specimens containing 5-similar-details, and the corresponding fatigue crack growth analysis with a fast prediction of crack growth life method were accomplished with finite element software. The comparison of crack tip position vs. load cycling from the test and the numerical simulation shows that the numerical simulation can give a good agreement to the experiment result.

The Equivalent Numerical Simulation of Fractured-Vuggy Carbonate Reservoir

2011 ◽  
Vol 110-116 ◽  
pp. 3327-3331 ◽  
Author(s):  
X. Xu ◽  
S. S. Tian ◽  
T. Xu ◽  
Y. X. Su
Keyword(s):  
Numerical Simulation ◽  
Carbonate Reservoir ◽  
Simulation Methods ◽  
Equivalent Permeability ◽  
Numerical Simulation Methods ◽  
Multi Media ◽  
The Law ◽  
Computing Method ◽  
Equivalent Continuum ◽  
Porosity Model

The storage spaces of carbonate reservoir are complicated, matrix pores, vugs, fractures and large caves are coexistence. Traditional numerical simulation methods have harsh requirement for geology model and computing method, these methods are not suitable for carbonate reservoir. A comparatively perfect equivalent permeability and porosity model for multi-media reservoir was developed based on the theory of equivalent continuum media and the law of equivalent seepage resistance. The equivalent parameters of a practical reservoir were calculated by this model, and a numerical simulation was carried out by using these parameters, the results showed that the equivalent numerical simulation of fractured-vuggy carbonate reservoir was reasonable.

Pore Water Pressure Distribution and Dissipation During Thaw Consolidation

2016 ◽  
Vol 116 (2) ◽  
pp. 435-451 ◽  
Author(s):  
Xiaoliang Yao ◽  
Jilin Qi ◽  
Mengxin Liu ◽  
Fan Yu
Keyword(s):  
Pressure Distribution ◽  
Pore Water ◽  
Pore Water Pressure ◽  
Water Pressure ◽  
Thaw Consolidation

Vocal Fold Tissue Failure: Preliminary Data and Constitutive Modeling†

2004 ◽  
Vol 126 (4) ◽  
pp. 466-474 ◽  
Author(s):  
Roger W. Chan
Keyword(s):  
Preliminary Data ◽  
Vocal Fold ◽  
Large Strain ◽  
Deformation And Failure ◽  
Rate Dependent ◽  
Nonlinear Stress ◽  
Tissue Specimens ◽  
Dependent Failure ◽  
Tissue Stresses

In human voice production (phonation), linear small-amplitude vocal fold oscillation occurs only under restricted conditions. Physiologically, phonation more often involves large-amplitude oscillation associated with tissue stresses and strains beyond their linear viscoelastic limits, particularly in the lamina propria extracellular matrix (ECM). This study reports some preliminary measurements of tissue deformation and failure response of the vocal fold ECM under large-strain shear. The primary goal was to formulate and test a novel constitutive model for vocal fold tissue failure, based on a standard-linear cohesive-zone (SL-CZ) approach. Tissue specimens of the sheep vocal fold mucosa were subjected to torsional deformation in vitro, at constant strain rates corresponding to twist rates of 0.01, 0.1, and 1.0 rad/s. The vocal fold ECM demonstrated nonlinear stress-strain and rate-dependent failure response with a failure strain as low as 0.40 rad. A finite-element implementation of the SL-CZ model was capable of capturing the rate dependence in these preliminary data, demonstrating the model’s potential for describing tissue failure. Further studies with additional tissue specimens and model improvements are needed to better understand vocal fold tissue failure.

Gurtin-Type Quasi-Variational Principle of Intelligent Structure Based on Nonlinear Theory

2010 ◽  
Vol 148-149 ◽  
pp. 1291-1295 ◽  
Author(s):  
Zong Min Liu ◽  
Hai Yan Song ◽  
Ji Ze Mao
Keyword(s):  
Variational Principle ◽  
Research And Development ◽  
Linear Theory ◽  
Nonlinear Theory ◽  
High Performance ◽  
Hot Spot ◽  
Large Strain ◽  
High Strength ◽  
Intelligent Structure ◽  
Intelligent Material

Intelligent structure is consistently identified as one of techniques getting much attention in the 21 century. With the research and development of intelligent material with large strain, high strength and high performance, the study on the non-linear theory of intelligent structure is a hot spot for research in the future. Based on nonlinear theory, Gurtin-type quasi-variational principle of nonlinear intelligent structure is established in this paper. Finally, some correlative problems are discussed.

Numerical Simulation of Stretchable and Foldable Silicon Integrated Circuits

2009 ◽  
Vol 74 ◽  
pp. 197-200
Author(s):  
Zhuang Jian Liu ◽  
Yong Wei Zhang ◽  
Ji Zhou Song ◽  
Dae Hyeong Kim ◽  
Yong Gang Huang ◽  
...  
Keyword(s):  
Thin Film ◽  
Numerical Simulation ◽  
Integrated Circuits ◽  
High Performance ◽  
Large Strain ◽  
Simulation Studies ◽  
Linear Elastic ◽  
Silicon Integrated Circuits ◽  
Elastic Responses ◽  
Principal Strains

This paper presents numerical simulation strategies for stretchable silicon integrated circuits that use stiff thin film on elastomeric substrates. Detailed numerical simulation studies reveal the key underlying aspects of these systems. The results indicate, as an example, optimized mechanics and materials for circuits that exhibit maximum principal strains less than 0.2% even for applied strains of up to ~90%. Simple circuits, including CMOS inverters provide an example that validates these designs. The results suggest practical routes to high performance electronics with linear elastic responses to large strain deformations, suitable for diverse applications that are not readily addressed with conventional wafer-based technologies.

scholarly journals One-dimensional large-strain thaw consolidation using nonlinear effective stress – void ratio – hydraulic conductivity relationships

2018 ◽  
Vol 55 (3) ◽  
pp. 414-426 ◽  
Author(s):  
Simon Dumais ◽  
Jean-Marie Konrad
Keyword(s):  
Heat Transfer ◽  
Hydraulic Conductivity ◽  
Effective Stress ◽  
Void Ratio ◽  
Moving Boundary ◽  
Initial Conditions ◽  
Large Strain ◽  
One Dimensional ◽  
Consolidation Theory ◽  
Thaw Consolidation

A one-dimensional model for the consolidation of thawing soils is formulated in terms of large-strain consolidation and heat-transfer equations. The model integrates heat transfer due to conduction, phase change, and advection. The hydromechanical behaviour is modelled by large-strain consolidation theory. The equations are coupled in a moving boundary scheme developed in Lagrangian coordinates. Finite strains are allowed and nonlinear effective stress – void ratio – hydraulic conductivity relationships are proposed to characterize the thawing soil properties. Initial conditions and boundary conditions are presented with special consideration for the moving boundary condition at the thaw front developed in terms of large-strain consolidation. The proposed model is applied and compared with small-strain thaw consolidation theory in a theoretical working example of a thawing fine-grained soil sample. The modelling results are presented in terms of temperature, thaw penetration, settlements, void ratio, and excess pore-water pressures.

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