A Mixture Finite Element for Reinforced Concrete
A semi-analytical finite element is presented for analyses of cracked reinforced concrete (RC) structures including bond action between rebar and concrete, and crack-face shear transfer....
Thermal Effects in a Transient Study of Fracture
Studies, e.g. Zehnder and Rosakis (1989), indicate that fracture is associated with temperature rises in inelastic zones near the crack edge. To gain more insight into this phenomenon,...
Analysis of Delamination Onset and Growth in Curved Laminates
This paper details an analysis to characterize delamination onset and growth from a matrix crack in a curved composite laminate. Finite element analysis was used to determine values of...
Analysis of a CMC Compact Tension Specimen
A cohesive force model is applied to study the stability of fiber failure in a ceramic matrix composite compact tension specimen. By controlling the length of the bridged crack results...
Interlaminar Fracture Toughness Test: Traditional and Modified
For brittle, transversely isotropic, composite materials we have developed an alternative Mode II interlaminar fracture toughness test (GIIc) that...
Characterization of Acoustic Emission Signals
Separation of crack growth signals is of fundamental importance for detecting, locating and determining the significance of an internal flaw using acoustic emission techniques. An analytical...
Use of Laser Holography and Image Analysis for Crack Measurement and Determination of Strain Fields in Cement Based Materials
The authors have successfully used laser holographic interferometry to measure various parameters, such as crack size, crack spacing, crack opening displacement, surface displacements...
Observations of Microcracking and Pore Collapse in Limestone Using Liquid Metal Porosimetry
A technique has been developed to preserve and observe the microstructure of rock or other porous material, as they exist under stresses, using liquid metal porosimetry. Cylindrical specimens...
Fracture Response of Cement Matrices Reinforced with High Volume Fiber Fraction
Toughening mechanisms of cement matrices reinforced with high volume fiber fraction have been experimentally studied by quantitative image analysis and laser holographic interferometry....
Bond Strength of Reinforcing Bars in SIFCON
This paper presents a brief summary of an ongoing investigation on the bond characteristics of deformed reinforcing bars embedded in a SIFCON matrix. A significant increase in bond strength,...
Experimental Techniques to Study the Microstructure of Cement-Based Materials
Techniques to identify phases and changes in microstructure within cement paste, mortar, and concrete using a scanning electron microscope and image analysis system are described. Backscattered...
Theoretical and Experimental Mechanisms of Toughening in Multi-phase Materials
Multi-phase materials are an important class of materials being developed for aerospace primary structural applications. Multi-phase materials are those materials consisting of two or...
On Statistical Micromechanical Process Damage Models for Brittle Solids with Interacting Microcracks
Two-dimensional micromechanical damage models with strongly interacting microcracks are presented to investigate the overall nonlinear mechanical responses of microcrack-weakened brittle...
Nonlocality of Continuum Approximation of Microcracked Materials
A continuum with nonlocal damage has recently been shown to be an effective approach for the analysis of strain-softening structures. The basic idea is that only the damage, normally caused...
Micro-Damage Process Model for Polycrystalline Ice
This paper presents a micro-damage process model for freshwater polycrystalline ice deforming at the high end of the ductile-to-brittle transitional domain of strain rated. Damage is attributed...
Crack Growth Stability in Ice
The mechanics of stable, time dependent crack growth as a function of geometry and increasing crack length in saline an freshwater columnar ice are examined in this paper. Experimental...
Moisture Diffusion in Concrete and Mechanisms of Drying Creep
The Pickett effect is the excess of creep at drying over the sum of shrinkage and basic creep. Several theoretical models have been presented to speculate on the mechanisms of this effect,...
A Model to Predict Restrained Shrinkage Cracking of Fiber Reinforced Concrete
Cracking due to restrained shrinkage occurs very often in an engineering practice, causing serious problems such as increased water permeability of the structure and corrosion of the reinforcement....
A Micromechanics Model for Rough Interfaces
A new constitutive model for transfer of interfacial tractions along rough cracks in strain softening composites is presented. The model relates the normal and shearing stresses on the...
Safeguarding History
Even monolithic marble monuments, such as the Thomas Jefferson Memorial, fall prey to materials deterioration. Now, sensitive instrumentation systems can document and analyze even the...
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