Foreign Investment in Latin America: A Second Look
It has become common to hear that Latin America has emerged from the lost decade of the 1980s, a period when virtually every country in the region suffered from high debt, high inflation...
Roller Compacted Concrete Tailing Retention Dam
A roller compacted concrete (RCC) dam has been designed for gold tailing impoundment in southeast Alaska. To minimize up front capital costs, the curved gravity dam with multiple outlet...
Passive Acoustic Emission for Quantitative Evaluation of Freeze Thaw and Alkali Aggregate Reaction in Concretes
Several experiments are reported in which the progression of freeze thaw (FT), alkali-aggregate reaction (AAR), and internal cracking caused by mechanical loading were monitored using...
Damage Assessment in Concrete Using Acoustic Emission
An acoustic emission (AE) is a localized rapid release of strain energy in a stressed material. This energy release causes stress waves to propagate through the specimen. These acoustic...
Study of Three Dimensional Crack Tip Location of Mortar by Acoustic Emission
Plain mortar specimens were tested under three-point bending. Experimental variables include the width of the specimen and the notch-to-depth ratio. The experimental results of 12 specimens...
Sonic NDE of Structural Concrete
Case histories are presented to illustrate applications of nondestructive evaluation (NDE) methods that use stress waves to characterize the conditions of concrete construction. The case...
Nondestructive Crack Identification by Acoustic Emission Analysis and Ultrasonic Frequency Response
Nondestructive evaluation (NDE) by the acoustic emission (AE) analysis and the ultrasonic testing (UT) on the spectral (frequency) response is studied to identify crack geometry. AE waveform...
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...
Geomechanics of Subsidence Due to Pumping of Groundwater
In this talk we describe a nonlinear theory for the classical problem of pumping of groundwater from a layered soil. The model soil system consists of three horizontal layers where a very...
On the Influence of Seismically Induced Residual Forces on Bridge Abutment Design
The seismic design of bridge abutments depend on the anticipated movement of the abutment during the design earthquake. For seat-type abutments in which the backfill resistance can be...
Damage Dependent Micromechanics in Metal Matrix Composites
A computational approach is used herein to model the effects of processing induced thermal residual stresses on radial, hoop, and shear stresses at the fiber/matrix interface in a continuous...
Behaviour of Prestressed Concrete End Blocks
This paper briefly reports on a series of experiments carried out on strip-loaded prestressed concrete end blocks. The results show that corresponding design methods presently used in...
Large Deformation Elastic Behavior of Low-Density Solid Foams
A strain energy function that describes the nonlinear elastic response of a three-dimensional open-cell foam is developed. A tetrahedral unit cell containing four half-struts that join...
Rate-Dependent Plasticity Representation for Energy-Absorbing Materials
A three dimensional rate-dependent plasticity constitutive model is developed for rigid polyurethane foams. In the model, the material is decomposed into skeleton and solid matrix from...
Constitutive Modeling and Simulation of Energy Absorbing Polyurethane Foam Under Impact Loading
The compressive-stress strain response of polyurethane foam under uniaxial compressive impact loading has been studied. The development of a uniaxial constitutive model from strain rate...
Random Aspect of the Stress Inside Granular Media
Micromechanics of granular media arose from the necessity of a better understanding of the relationship between the global behaviour of such materials and the physical phenomena which...
Use of Hierarchical Lattices for Predicting the Fluid or Stress Transfer in Concrete
Hierarchical lattices are used to study the influence of local disorder on the transfer of properties (stresses, strains, permeability) from the micro-scale to the macro-scale. They are...
On the Diffusional Stress Transmission
A probabilistic diffusional mechanism for the propagation of intergranular forces has been formulated as a set of three mathematical assumptions. The equilibrium equations are complemented...
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...
Comparative Evaluation of Plasticity Theories Against Tension-Torsion Test at Finite Strain
This paper investigates and evaluates three hardening theories against a variety of nonproportional loading experiments on tubes made of annealed copper. It was concluded that the isotropic...
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