Refined Analysis of Load Distribution Factors for Bridges
This paper presents a new approach for calculating the distribution factors for slab-on-girder bridges. This method considers the coupling of longitudinal and transverse effects. The governing...

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...

Soil Behavior from Unconventional Loading Conditions
Random and sinusoidal loading conditions were used in this study to determine the soil moduli and the damping ratios of cohesive soil samples. Test results showed some differences between...

Experimental Photoelastic Analysis of Tunnels Containing Cracks
Due to the presence of cracks the strength of the structure is decreased in the present paper an experimental two dimensional photoelastic technique has been developed to analyze the circular...

Instability of Slopes with Nonassociated Flow
Experimental investigations of the conditions for instability have shown that granular materials may become unstable inside the failure surface. For states of stress below the failure...

Analysis of Internal Discontinuities in Geo-Materials
A new approach for modeling localized deformations is proposed. This approach uses an interface element to model the shear band. A successful capture of the kinematics of a failure mechanism...

Dynamic Analysis of Sliding Seismic Isolators
The friction pendulum system (FPS) sliding seismic isolators are being used for the seismic isolation rehabilitation of the U.S. Court of Appeals Building, San Fransisco. This paper will...

Direct Tensile Test: Stability and Bifurcation
Unnotched specimens of quasibrittle materials that exhibit post-peak strain softening do not deform symmetrically in a direct tension test. The phenomenon (which is similar to the recently...

Determination of In-Situ Stresses From Acoustic Emissions
Acoustic emissions (AE) are microseismic activities that are generated in concrete by cracking and damage. The rate of Acoustic Emissions, called the 'Event Rate', can provide indication...

Evaluating Polymer Concrete Bridge Expansion Joints Using Acoustic Emission
This study is to simulate the acoustic emission (A/E) of polymer concrete bridge expansion joints subjected to controlled representative loads by a rotating test apparatus on a circular...

Micromechanical Simulation of Wave Propagation in Dense Granular Assemblies
Two-dimensional DEM with modified Mindlin's contact law has been used to study the load transfer mechanisms in 'consolidated' granular assemblies. Results of simulation are presented and...

Neural Network Modeling of the Mechanical Behavior of Sand
Given a set of triaxial test data, an artificial neural network (ANN) has been trained to model the mechanical behavior of a medium-to-fine sand. Once trained, the ANN was tested by simulating...

Computer Simulation of Direct Shear Test
This paper presents a pilot study of a computer simulation of direct shear test on sands using the Discrete Element Method. The numerical test setup is described first, which is followed...

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...

Constitutive Modeling for Material with Perfect Disordered Heterogeneity
Finite element analysis with large number of elements are performed to simulate perfect disordered heterogenous material. The probabilistic nature of the micromechanical behavior of the...

Vortex Suppression in Wet-Pit Pump Intakes
Two distinct examples to suppress both air-entraining and boundary-attached subsurface vortices in large vertical pump intakes are presented that were developed by means of hydraulic model...

Automated Identification of Compression-Induced Cracking in Cement Paste
The development of image analysis techniques to identify cracks using scanning electron microscope images of hydrated cement paste is described. Cracks are identified based on both the...

High-Resolution Interwell Seismic Experiments in Sedimentary Formations
High-frequency interwell seismic data were acquired to examine full waveforms recorded in the pulsed mode and in the swept mode as well as to perform traveltime inversion tomography for...

A Wax-Coupled Borehole Seismic Detector for High-Resolution Measurements
A triaxial borehole seismic detector was developed for high-resolution measurements at frequencies up to 2,000 Hz. Applications for this detector include three-component shallow reverse...

Ultrasonic Wave Scattering by a Crack in a Composite Plate
A hybrid method is presented for analyzing ultrasonic wave scattering of plane strain waves by a crack in a composite plate. The hybrid method combines a finite element formulation in...

 

 

 

 

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