Numerical Integration of Transient Creep Constitutive Equations for Polycrystalline Ice
A numerical time integration algorithm is developed to solved the system of coupled, first-order differential equations characterizing the physically-based constitutive model of Shyam...
Improved Time-History Analysis for Structural Dynamics Calculations
Methods are developed to reduce the computational effort in time-history analysis of nonlinear structures. The methods permit use of much larger time intervals than are possible in conventional...
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...
Nonlinear Dynamic Response of Framed Structures Using the Mode Superposition Method
This paper describes a methodology for nonlinear dynamic response analysis of framed structures using the mode superposition method. A portal frame example is presented and compared to...
Free Vibration Analysis of Asymmetric Buildings
A simple procedure for free vibration analysis of asymmetric buildings is presented. This method assumes that each floor is a rigid diaphragm with three degrees of freedom (two lateral...
Resonant Column Testing of Dynamic Rock Properties
Critical parameters for geophysical wave propagation studies are the dynamic elastic properties (shear and Young's moduli, and Poisson's ratio) and the intrinsic material damping of rocks....
Response of Mono-Coupled Distributed Parameter Systems to Random Excitation
The random vibration of periodic structures consisting of a multiplicity of closely coupled distributed parameter substructures is addressed. The problem formulation is general, and the...
Dynamic Response Analysis of Pile Foundations by Using Variational Calculus
Various approaches have been developed for the frequency-domain dynamic response analysis. The one proposed by M. Novak (1974) is simplest of all and yet produces the results very close...
Experimental and Theoretical Dynamic Compliances of Foundations
An experimental study of the dynamic behavior of surface foundations on granular soils by centrifuge modeling is presented. The test method allows a direct measurement of the complex-valued...
Similarity Solutions of Starting Jets and Starting Plumes
Similarity solutions of the starting jets and the starting plumes are obtained using a one dimensional model based on the top-hat profiles and the symmetry assumption for the velocity...
Shear Flow Between Walls in Relative Motion
The paper reports on experiments on Couette flow, i.e., the shear-induced flow between surfaces which are in motion relative to each other. The novel aspect of the work is the appearance...
Harmonic Excitation of an Unconstrained Saturated Particle Bed
Past research on the flow of concentrated cohensinless mixtures have historically emphasized steady or quasi-steady motions while dynamic effects have received little attention in comparison....
Dynamic Stability of Composite-Material Circular Cylindrical Shells with Orthogonal Stiffeners
The governing equations are formulated for general (axisymmetric or unsymmetric) vibrations of thin circular cylindrical shells of composite material and reinforced with axial (stringer)...
Equivalence Between Motions with Noise-Induced Jumps and Chaos with Smale Horseshoes
For certain sets of parameters multi-stable oscillators excited by noise can exhibit irregular jumps. We consider one-degree-of-freedom near-integrable multi-stable systems whose unperturbed...
Bifurcations and Chaos in Structural Control
We study a harmonically forced oscillator with nonlinear soft spring subjected to a linear feedback control with time delay. This system can be written as a three dimensional dynamical...
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...
Updating Dynamic Models and Their Associated Uncertainties for Structural Systems
The problem of updating a structural model and its associated uncertainties using dynamic test data is addressed, considering uncertainties which arise from measurement noise, modeling...
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....
Leakage Characteristics of the St. Jude Heart Valve
The requirement for anticoagulant therapy in patients implanted with mechanical heart valve prostheses is well known. A plausible explanation for this requirement is that the leakage flow...
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...
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