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...
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...
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...
Stress Relaxation Analysis for Sealants
A solution method for stress relaxation analysis of systems composed linear viscoelastic material in a state of plane strain is presented. The incremental, finite element method takes...
Nonisothermal Viscoplasticity
A nonisothermal theory of viscoplasticity is formulated for a medium subjected to finite deformation. The basic system of equations consists of the laws of conservation of linear and angular...
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...
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...
Relationships Between Error Estimation and Adaptive Computations in Strain Localization
In this work, the a posteriori error estimates and the h mesh refinement techniques using hierarchical finite element shape functions are tailored for numerical simulations of strain localization...
On the Bifurcation of Elasto-Plastic Crystals During Multiple Slip
Conditions for the localization of deformation in elasto-plastic crystals experiencing multiple slip are discussed using multisurface plasticity theory. In particular, some important characteristics...
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