Nonlinearities and Imperfections in Creep Stability
The effects of material and geometric nonlinearities and imperfections on the 'safe-load-limit' and the 'safe-service-period' of structures...

Propagating Buckles in Deep-Water Pipelines
A procedure is presented for the analysis of propagating buckles in deep-water pipelines. Results pertaining to quasistatic and dynamic buckles are summarized and compared with available...

Perplexing Issues in Concrete Softening
We explore some of the proposed techniques for modeling 'softening' via the constitutive model. We seek a framework which is both theoretically sound and physically...

On Isotropic and Anisotropic Damage Variables in Continuum Damage Mechanics
The present work analyzes the implication and limitation of some 'scalar damage' models. In particular, the elastic-damage thermodynamic potential and the 'effective...

A Kinematic Hardening and Softening Model of Concrete
In the present paper, a new loading surface calibrated by several typical uni- and multi-axial test curves is proposed. Following the associated flow rule, a relatively simple constitutive...

Inelastic Mechanisms in Dynamically Loaded Ceramics
The dynamic response of ceramic materials has been the subject of intense research in the past decade. In this paper, we succinctly describe a plate impact experiment of a star-shaped...

Healing or Negative Damage in Concrete
The deformation of concrete may be attributed to damage or the evolution of microcracks and to mechanical healing or the closing of microcracks. For damage, dissipation is positive but...

One Surface Model for Concrete with Non-Associated Damage Rule
The general formulation of a continuum theory for the inelasticity of concrete is derived. The internal theory of thermodynamics is used and the dissipation inequality is established....

Cooperative Fracture?Statistical Models
The brittle failure of certain engineering materials represents but an ultimate phase in a process characterized by an evolving system of microdefects distributed over a large part of...

Large Deformation Analysis of Cardiac Structures
The finite element technique can be used to simulate the response of the cardiac structures that have complex shape and geometry and nonlinear material properties. This paper enumerates...

Non-Linear Passive Elastic Properties of the Left Ventricular Myocardium: Application of Finite Element Analysis to 3-D Geometry Obtained from Ultrasound Images
A finite element (FE) analysis and an optimization algorithm were employed to assess the nonlinear passive elastic properties of left ventricular myocardium in a canine mode. The three-dimensional...

Effect of Stenotic Geometry on Blood Flow Behavior
The dynamic characteristics of the blood flow is affected by the area reduction of stenosis. To estimate the severity of stenosis, the information about the geometry should also be accounted....

Three-Dimensional Blood Flows Associated with Intra-Aortic Balloon Counterpulsation
Three-dimensional blood flow processes associated with intra-aortic balloon counterpuslation (IABP) are calculated using a Cray YMP supercomputer. The mathematical model incorporates a...

Effects of Artificial Heart Pumping on Hemorheology
Alterations in hemorheology were studied in 19 patients supported by the Jarvik-7 total artificial heart (TAH) anywhere from 1 to 48 days as a bridge-to-cardiac transplantation. Abnormally...

Structural Aspects of Femoral Head Osteonecrosis
Orthopaedic management of early stage osteonecrosis (ON) of the femoral head is aimed at delaying or preventing collapse of structurally weakened regions of repairing dead bone. The advent...

Contact Problems in Cell Adhesion
Adhesion of biological cells plays an important role in many physiological processes. For instance, the adhesion of killer T-lymphocyte to its target cell is an essential step in cytolysis,...

Computational Mechanics: Constitutive Modeling and Performance Analysis
The availability of supercomputers in the 80's has brought about a revolution in the analysis and design of complex structures. Parallel with this, computers have played a...

Optical Performance Predictions and Testing of a Composite Reflector
This paper describes the structural analysis and the experimental performance evaluation of advanced composite mirror designs for future NASA astrophysics missions. An interdisciplinary...

Modelling of Tubes with Large Plastic Deformation
A thin circular tube laterally compressed between two rigid plates is investigated for its load(P)-displacement(?) behaviour. The moving hinge concept yields a good prediction compared...

Using a Linearized Yield Surface in Dynamic Analysis
This paper describes an application of the finite element method to dynamic analysis of systems which exhibit material nonlinearity. A time history approach is used with a central difference...

 

 

 

 

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