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...
Axial Force-Moment Interaction in System Reliability
For rigid-plastic structures with random resistances and loads, a technique is presented that identifies critical failure modes considering the effect of axial force-moment interaction...
An Efficient Algorithm for Second-Order Finite Element Reliability Analysis
A new, efficient algorithm for computing the principal curvatures of the limit-state surface at the design point, which are employed in second-order reliability analysis, is described....
An Adaptive Importance Sampling Strategy
An adaptive importance sampling scheme is presented. The scheme updates both the estimate of system failure probability and the importance sampling density. The sampling density used is...
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...
Two Dimensional Analysis of Strain Localization with Nonlocal Continuous Damage
This paper addresses the problem of damage localization from a theoretical stand point with a nonlocal model. Conditions for non uniqueness of the rate equations of equilibrium are derived...
Tensile Failure in Concrete by Spallation
Plate impact experiments were performed on concrete specimens to study tensile failure at high strain rates. For tensile stress pulse durations of 1.5 and 2.2 ms the threshold stress for...
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...
Computational Damage Modeling for Timber Reliability Analysis
Damage models for creep-rupture are used in conjunction with stochastic load models to evaluate lifetime failure probabilities of timber members and systems. This paper examines damage...
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...
Numerical Simulation of Dam-Breaking Waves
Recently, as a high-resolution numerical technique, the Total Variation Diminishing (TVD) method is applied to Aerodynamic shock problems successfully. In this paper, a Total Variation...
Parametric Excitation of Collapsible Latex Tubes
In 1985, Liu and Ding (1989) made an experiment of collapsible tubes containing a pulsatile flow. A latex tube is sealed up in a plexiglass chamber. If the transmural pressure (TP) 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...
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