A feasibility study for a Concrete Core Tomographer
This is a study of the feasibility of applying computer tomography in the study of concrete cores. A laboratory protocol is presented for testing concrete cores using a medical - grade...
Concrete Surface Characterization Using Optical Metrology
The displacement of the surface of a concrete specimen is measured as it cures using an optical method. This method, known as optical metrology, is one in which a line is projected onto...
On a Micromechanical Basis of Stochastic Constitutive Laws
A procedure for derivation of stochastic constitutive laws is outlined on the basis of graph-representable linear elastic microstructures. Central to the procedure is the concept of a...
Characterization of Granular Material Composite Structures Using Computerized Tomography
The behavior of particulate composites such as asphaltic concrete is controlled by microstructural features including particle and binder arrangements, interparticle contacts, and changes...
Densification/Creep Behavior of Experimental Glass-Ceramic Waste Forms for Immobilization of High-Level Calcined Waste at the Idaho Chemical Processing Plant
A mixture of simulated high-level calcined waste (HLW) and Frit additives was hot isostatically pressed (HIPed) to a dense glass-ceramic waste form. A densification mapping software was...
Stochastic Response of a Caster-Mounted System
The response statistics of a caster-mounted system with white noise excitation are estimated using the generalized equivalent linearization method. The displacement and velocity covariances...
Three-Dimensional Fracture Process Zone Detection in Concrete
Process zones in concrete have been under intensive investigations during the past several years. Techniques have successfully been used to detect and map the 2-D superficial process zone....
Stochastic Modeling of Fatigue Crack Growth with Retardation
This paper develops a new methodology for modeling fatigue crack growth accounting for both material inhomogeneity and the random nature of the loading process by modeling the crack growth...
Probabilistic Micromechanics in Constitutive Modeling of Granular Material
This paper gives a review of newly developed probabilistic methods for analysis of the effect of randomness in geometry and physical properties at the microscale on their macroscale response...
Modal Coupling Effect of Non-Classically Damping
The equations of motion of a structure in undamped modal coordinates may have non-zero off-diagonal terms in the damping matrix. Although these terms are commonly neglected, studies have...
On the Modelling of Damage Due to Volumic Variations in Cementitious Composites
Two kinds of volumic variations are considered. Those due to thermal gradients on hardened concrete and those due to hydration processes at early ages. Models based on damage mechanics...
Nonstationary Response Characteristics of Linear MDOF Systems
A new approximate methodology for nonstationary random vibration analysis of multi-degree-of-freedom linear systems is developed. Simple analytical expressions for the covariance response...
Analog Electronic Simulations of a Nonlinear System
We perform electronic analog simulations of a harmonically forced Duffing oscillator. The addition of noise perturbations of sufficient intensity is shown to induce transitions between...
Systolic Anterior Motion of the Mitral Valve: In Vitro Flow Studies
Using an in-vitro approach, the goal of this study was to determine and to characterize the mechanism of systolic anterior motion of the mitral valve in obstructive hypertrophic cardiomyopathy....
Flow Visualization Studies in the Novacor Left Ventricular Assist System
This paper discusses a series of experiments to visualize and measure flow fields in the Novacor left ventricular assist system (LVAS). The experiments utilize a multiple exposure, optical...
Computational Gradient Plasticity
The inclusion of higher-order deformation gradients is of paramount importance for properly describing strain localization within the framework of continuum mechanics. In this contribution...
Discrete Markov Process Approach to Fatigue Crack Growth
The discrete Markov approach considered herein is simple to implement and uses a two-dimensional stochastic model in conjunction with simulation to estimate model parameters. The possibility...
Stochastic Mixed Finite Difference Method
Some aspects of numerical solutions of stochastic mechanics problems are considered. The Finite Difference method for discretization of stochastic continuous media problems is discussed....
Structural Control Under Stochastic Seismic Loads
This paper presents a method of controlling nonlinear and hysteretic civil engineering structures subjected to stochastic earthquake ground excitations. Emphasis is placed on control of...
Pressure Losses Across Sequential Stenoses in Collapsible Tubing
The fluid dynamics of a model of a diseased artery with multiple stenoses were investigated in a recirculating steady-flow system over a range of Reynolds numbers (Re) from 30 to 1100....
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