A Method to Calculate Pack Ice Driving Forces

1995 ◽  
Vol 117 (2) ◽  
pp. 145-150
Author(s):  
E. Evgin ◽  
C. Zhan ◽  
R. M. W. Frederking
Keyword(s):  
Driving Forces ◽  
Stress Distributions ◽  
Nonlinear Analyses ◽  
Creep Equation ◽  
Finite Element Program ◽  
Linear Elastic ◽  
Pack Ice ◽  
Short Period ◽  
Stress Levels ◽  
Element Program

A method is proposed to calculate pack ice driving forces. In order to develop the method, stress distributions in a circular ice floe are calculated for various boundary loading conditions. The analysis is carried out using a special-purpose finite element program in which Sinha’s creep equation is used to model the behavior of ice. Charts relating pack ice driving forces to stresses in the ice floe are produced for both linear elastic and creep equations for ice behavior. The results indicate that, for a short period of loading time and at low stress levels, a linear elastic analysis can be used to calculate the pack ice driving forces. However, when the stress levels in the ice floe are high or the time span of load application is long, linear and nonlinear analyses produce much different values for pack ice driving forces.

Elastic Analysis of Journal Bearings

Volume 1 ◽  
2004 ◽  
Author(s):  
M. M. Villar ◽  
M. M. Pe´rez
Keyword(s):  
Stress Distribution ◽  
General Purpose ◽  
Von Mises Stress ◽  
Elastic Analysis ◽  
Stress Distributions ◽  
Finite Element Program ◽  
Relative Significance ◽  
Element Program ◽  
Von Mises ◽  
Hoop Stresses

In this paper a numerical model is used to investigate the effect of the elasticity of the bearing in the pressure distribution in the lubricant and the stress distribution in the bearing. The lubricant film, as well as a bearing, including the lining and the backing of the insert, and the housing, are modeled using the general-purpose ANSYS®5.7 commercial Finite Element program. Results have been obtained for the pressure, radial displacement, hoop and von Mises stress distributions at the surface of the bearing, as well as for the shear stress distribution at the interface between the lining and the backing. A number of conclusions have been drawn regarding the relative significance of the steep pressure gradient at the end of the lubricated region on the hoop stresses that cause localized bending distortions at the surface of the lining. These localized bending distortions, in turn, are likely to cause fatigue failure of the lining.

Anisotropic Modeling of Granular Bases in Flexible Pavements

1997 ◽  
Vol 1577 (1) ◽  
pp. 18-26 ◽  
Author(s):  
Erol Tutumluer ◽  
Marshall R. Thompson
Keyword(s):  
Flexible Pavements ◽  
Triaxial Tests ◽  
Anisotropic Model ◽  
Wheel Load ◽  
Finite Element Program ◽  
Linear Elastic ◽  
Element Program ◽  
Stress Dependent ◽  
Repeated Load Triaxial ◽  
Simple Stress

A new cross-anisotropic model is proposed to predict the performance of granular bases in flexible pavements. A cross-anisotropic representation has different material properties (i.e., elastic modulus and Poisson’s ratio) assigned in the horizontal and vertical directions. Repeated-load triaxial tests with vertical and lateral deformation measurements can be used to establish these anisotropic properties. Simple stress-dependent granular material models, obtained from analysis of the laboratory test data, are used in a nonlinear finite element program, named GT-PAVE, to predict pavement responses. The horizontal and shear stiffnesses are typically found to be less than the vertical. The nonlinear anisotropic approach is shown to account effectively for the dilative behavior observed under the wheel load and the effects of compaction-induced residual stresses. The main advantage of using a cross-anisotropic model in the base is the drastic reduction or elimination of significant tensile stresses generally predicted by isotropic linear elastic layered programs.

A Material Model for Prediction of Fatigue Damage and Degradation of CFRP Materials

2017 ◽  
Vol 742 ◽  
pp. 740-744 ◽  
Author(s):  
Jörg Hohe ◽  
Monika Gall ◽  
Hannes Gauch ◽  
Sascha Fliegener ◽  
Zalkha Murni binti Abdul Hamid
Keyword(s):  
Fatigue Damage ◽  
Low Cycle Fatigue ◽  
Damage Model ◽  
Material Model ◽  
Finite Element Program ◽  
Damage Evolution Equation ◽  
Brittle Damage ◽  
Linear Elastic ◽  
Element Program ◽  
Definition Of

Objective of the present study is the definition of a material model accounting for fatigue damage and degradation. The model is formulated as a brittle damage model in the otherwise linear elastic framework. A stress driven damage evolution equation is derived from microplasticity considerations. The model is implemented as a user-defined material model into a commercial finite element program. In a comparison with experimental data in the low cycle fatigue regime, a good agreement with the numerical prediction is obtained.

Analysis of Ultimate Load-Bearing Capacity of Long-Span CFST Arch Bridges

2011 ◽  
Vol 90-93 ◽  
pp. 1149-1156 ◽  
Author(s):  
Yang Liu ◽  
Da Wang ◽  
Yi Zhou Zhu
Keyword(s):  
Bearing Capacity ◽  
Failure Modes ◽  
Ultimate Load ◽  
Elastic Buckling ◽  
Load Bearing Capacity ◽  
Finite Element Program ◽  
Load Bearing ◽  
Linear Elastic ◽  
Long Span ◽  
Element Program

In order to study the ultimate load-bearing capacity of the long-span concrete-filled steel tubular (CFST) arch bridge with fly-bird-type, the ANSYS finite element program was used to establish its special model, and to study ultimate load-bearing capacity of this bridge with three different methods. The constitutive relation factors of concrete-filled steel tubular was taken into consideration including confining effect ultimate load coefficients, failure modes, and load-displacement curves of this bridge under different cases. The result indicate that the ultimate load-bearing capacity of the bridge can meet the requirement, all of its failure modes is out-plane, the two methods, linear elastic buckling analysis and only geometric nonlinearity analysis, will over high estimate ultimate load-bearing capacity of this bridge, and linear elastic buckling method cannot reflect real failure mode of this structure. In order to correctly estimate the ultimate load-bearing capacity of the bridge structure, the effect of geometric and material double nonlinearity couldn’t be neglected.

Stress Singularity at the Free Surface of a Dynamically Growing Crack

1990 ◽  
Vol 57 (1) ◽  
pp. 112-116 ◽  
Author(s):  
Peter Gudmundson ◽  
So¨ren O¨stlund
Keyword(s):  
Free Surface ◽  
Crack Front ◽  
Isotropic Material ◽  
Stress Singularity ◽  
Crack Tip ◽  
Finite Element Program ◽  
Linear Elastic ◽  
Growing Crack ◽  
Element Program ◽  
Tip Velocity

The stress singularity at the intersection between the crack front and the free surface of a dynamically growing crack in a linear elastic isotropic material has been numerically evaluated by an especially developed finite element program. The singularity parameter (λ), defined by σ ~ Rλ−1, is presented as a function of the crack-tip velocity and the angle (β) between the crack front and the free surface. The angle (β) at which the singularity (λ) equals 0.5 was found to be 101 deg almost independently of the crack-tip velocity.

Analysis of a Caisson Retained Island

1988 ◽  
Vol 110 (2) ◽  
pp. 68-76
Author(s):  
E. Evgin ◽  
S. Lord ◽  
I. Konuk
Keyword(s):  
Finite Element ◽  
Dimensional Analysis ◽  
Three Dimensional ◽  
General Purpose ◽  
Two Dimensional ◽  
Nonlinear Analyses ◽  
Stress Strain ◽  
Finite Element Program ◽  
Stress Strain Relation ◽  
Element Program

The results of the two and three-dimensional, nonlinear analyses of a caisson retained island in the Beaufort Sea are presented. A hyperbolic stress-strain relation for soils has been implemented in a general purpose finite element program, ADINA, to carry out the analysis. Based on the comparisons of the results, conclusions were drawn about whether a two-dimensional analysis can be safely used to replace a three-dimensional analysis.

scholarly journals Application of Fracture Mechanics to Cracking Problems in Soils

2014 ◽  
Vol 8 (1) ◽  
pp. 1-8 ◽  
Author(s):  
G. Juárez-Luna ◽  
G. Ayala
Keyword(s):  
Fracture Mechanics ◽  
Numerical Models ◽  
Practical Interest ◽  
Critical Stress Intensity Factor ◽  
Critical Conditions ◽  
Finite Element Program ◽  
Linear Elastic ◽  
Element Program ◽  
Elastic Fracture ◽  
Geotechnical Studies

This paper analyzes the problem of fracture in soils using the linear elastic fracture mechanics theory. Six cases of practical interest are investigated where the soil is subjected to different critical conditions that may produce cracks. To model the phenomenon of crack propagation, a two-dimensional fracture mechanics finite element program is used. In all cases, the properties of clays in the Valley of Mexico was used. The self-weight of the soil is considered as the main cause of geostatic stresses in the medium. Based on results from previous studies, the value of the critical stress intensity factor is calculated and validated. It is assumed that, only mode I fracture occurs. The crack depths obtained with the numerical models are congruent with the field data of existing geotechnical studies in the Valley of Mexico.

Friction Force and Stresses Analysis for Contact of Assembled Details

2006 ◽  
Vol 113 ◽  
pp. 334-338
Author(s):  
Z. Dreija ◽  
O. Liniņš ◽  
Fr. Sudnieks ◽  
N. Mozga
Keyword(s):  
Mechanical Properties ◽  
Surface Roughness ◽  
Plastic Deformation ◽  
Friction Force ◽  
Sliding Friction ◽  
Friction Model ◽  
Contact Interface ◽  
Finite Element Program ◽  
Elastic Plastic ◽  
Element Program

The present work deals with the computation of surface stresses and deformation in the presence of friction. The evaluation of the elastic-plastic contact is analyzed revealing three distinct stages that range from fully elastic through elastic-plastic to fully plastic contact interface. Several factors of sliding friction model are discussed: surface roughness, mechanical properties and contact load and areas that have strong effect on the friction force. The critical interference that marks the transition from elastic to elastic- plastic and plastic deformation is found out and its connection with plasticity index. A finite element program for determination contact analysis of the assembled details and due to details of deformation that arose a normal and tangencial stress is used.

Sign in / Sign up

Export Citation Format

Share Document