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...
Routes to Chaos of a Vertically Rotating Pendulum
Each blade of a mechanical shredder may be modeled by a pendulum whose pivot rotates in a vertical circle. The transition to chaos of small periodic motion about radial lines us the driving...
Regularization Methods for Identification of Structural Damage
Generally, various non-unique solutions may be obtained from ill-conditioned equations. Several methods are available to obtain a unique (minimum energy) solution to a modified and thus...
Applications of Viscoelastic Damper to Jointed Structures for Seismic Mitigation
Some structures, such as dams, are built with contraction joints that might carry some small tensile stresses. Such joints are expected to open and close during an earthquake. That will...
Effect of Active Control on Closely Spaced Natural Frequencies
Current problems in structural control involve structures with closely spaced natural frequencies (M.J. Balas, 1983). The purpose of this paper is to show how control affects a structure...
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...
An Evaluation Study of Modified Mohr-Coulomb and Cap Models
Two failure criteria, namely Mohr-Coulomb and cap models, are considered in this paper with some modifications. Mohr-Coulomb theory is applied to concrete after stress and strain cut-offs...
Seismic Stability Analysis of Landfill
The failure mechanism of a waste containment system is not well understood due to the complexity and the heterogeneity of the system. The recent slope failure of the Kettleman Hills waste...
Computer Simulation of Granular Flows
Discrete-particle computer simulations using up to 15,000 identical spheres reproduce particle-scale information obtained from high-speed motion picture observations of disperse, collision-dominated...
Computer Simulation of Dry Layered Granular Flow Down an Incline Composed of Grains
Experiments show that gravity-driven dry granular flows are essentially layered for smooth spheres. This paper describes layer-to-layer interaction in the flow. Assuming two-dimensional...
Numerical Simulation of a Sphere Moving Down an Incline with Identical Spheres Placed Equally Apart
This paper describes a numerical study of an elastic sphere moving down an incline with a string of identical spheres placed equally apart. Two momentum equations and a moment equation...
A Sphere Moving Down an Inclined Bumpy Surface
A sphere moving down a bumpy incline in the air is studied theoretically and experimentally. A method based on the principle of energy conservation is used to express the average velocity...
Distributed Failure Analysis, Fallacies and Remedies
In the past, two distinctly different approaches - smeared and discrete failure descriptions have been utilised to capture failure mechanisms in solids and structures. These two approaches...
Failure Analysis of Masonry Structures
The use of smeared-crack and interface elements for the analysis of masonry structures is investigated. While a variety of structural problems can be solved with a combination of both...
Numerical Analysis of Discrete Nonlinear Fracture Mechanics
Because cementitious materials tend to fail by fracture along discrete interfaces, it makes sense to analyze this behavior with discrete nonlinear fracture mechanics. Using the finite...
Computational Framework for 3D Nonlinear Discrete Crack Analysis
Under contract from the Electric Power Research Institute (EPRI) to investigate the applicability of fracture mechanics to concrete dams, the authors are involved in the development of...
Frequency Response of Disordered Periodic Structures
A computational procedure is given for calculating the frequency response of disordered periodic structures based on wave propagation theory. An ideal periodic structure is composed of...
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