Responses of Bilinear and Impacting Systems Subjected to Regular Waves
The dynamic responses of bilinear and impacting oscillators subjected to harmonic loadings are investigated. Differing from previous studies in which bifurcation diagrams were developed...
Mechanical Response of Cellular Materials Used in Waste Shipping Containers
Material behavior of impact limiters such as aluminum honeycombs and polyurethane foams has been studied experimentally. Four densities of aluminum honeycombs were tested: 3, 8, 12, and...
Multiple Modes of Steady-State Slide-Rock Response
The dynamic response of free standing rigid bodies to base excitation can be quite complex, as evidenced by the five motions or modes to be considered in a two-dimensional analysis: rest,...
Dynamic Effect of Sediment on Dam Hydrodynamics
The dynamic behavior of reservoir sediment during earthquakes is important to an analysis of dam safety when the depth of the water is seriously reduced by the sediment. While the dynamic...
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...
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...
Sensitivity of Lifeline Response to Models for the Spatial Incoherence of the Seismic Ground Motions
The sensitivity of the response of above-ground and buried lifelines to different models describing the spatial variability of the seismic ground motions is examined. It is shown that...
First-Passage Failure Predictions for Yielding Primary-Secondary Systems
Approximate methods are used to investigate the effect of nonnormality (non-Gaussianity) on the time of first-passage failure for a linear secondary system mounted on a yielding primary...
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...
Wave Propagation in a Nonlocal Strain-Softening Continuum
The problem of wave propagation in a nonlocal strain softening solid is first discussed analytically. It is demonstrated that 'loading' waves can still propagate in the strain softening...
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...
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...
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....
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...
Modeling the Chaotic Behavior in Simple Shear Granular Flows
Simple shear granular flows have demonstrated a variety of puzzling phenomena. Both computer simulations and physical experiments have discovered particle grouping, layering and shear...
Tripod Crane Concept for Lunar Surface Construction
A construction scheme using three integrated cranes is proposed. Mikulas proposed a lunar crane concept which introduces a set of three cables in order to stabilize the payload. This paper...
Cargo Transport to the Lunar Surface Using a Three Rotor Sling
The three rotor sling, a momentum transfer device, is described. The dynamics of multi-rotor systems are explained, and the three rotor system is shown to be favored over one and two rotor...
Principles of Control for Robotic Excavation
Excavation can be considered one of the most unstructured problems in the construction environment. On one hand, many technologies have been developed in the past to build shelters using...
An Analysis of Human Performance in Simulated Partial-Gravity Environments
Three unique partial gravity test environments; parabolic flight, water immersion and a mechanical-relief device provide the environment to evaluate human locomotion, reach sweeps, and...
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