Perplexing Issues in Concrete Softening
We explore some of the proposed techniques for modeling 'softening' via the constitutive model. We seek a framework which is both theoretically sound and physically...
Two Dimensional Analysis of Strain Localization with Nonlocal Continuous Damage
This paper addresses the problem of damage localization from a theoretical stand point with a nonlocal model. Conditions for non uniqueness of the rate equations of equilibrium are derived...
Tensile Failure in Concrete by Spallation
Plate impact experiments were performed on concrete specimens to study tensile failure at high strain rates. For tensile stress pulse durations of 1.5 and 2.2 ms the threshold stress for...
Healing or Negative Damage in Concrete
The deformation of concrete may be attributed to damage or the evolution of microcracks and to mechanical healing or the closing of microcracks. For damage, dissipation is positive but...
Computational Damage Modeling for Timber Reliability Analysis
Damage models for creep-rupture are used in conjunction with stochastic load models to evaluate lifetime failure probabilities of timber members and systems. This paper examines damage...
One Surface Model for Concrete with Non-Associated Damage Rule
The general formulation of a continuum theory for the inelasticity of concrete is derived. The internal theory of thermodynamics is used and the dissipation inequality is established....
Diastolic Function Using 3-D Echo Reconstruction and Finite Element Analysis: Applications for Study in Animal Models and Patients
We have initiated animal experiments using three-dimensional reconstruction of echocardiographic recordings and finite element analysis to evaluate the effects of alterations in preload,...
R/C Columns Under Axial and Bi-Directional Lateral Loads
The reliability of a model, called a multi-spring model, was examined to simulate the observed response of reinforced concrete columns subjected to varying high axial loads and bi-directional...
Using a Linearized Yield Surface in Dynamic Analysis
This paper describes an application of the finite element method to dynamic analysis of systems which exhibit material nonlinearity. A time history approach is used with a central difference...
Computational Failure Analysis of Reinforced Concrete Plate Structures
The paper summarizes our recent effort in developing a suitable finite element code for the failure prediction of reinforced concrete structures. The basis of the development is a plasticity...
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....
Nonlinear Response of Ground Supported Slabs
Refined techniques for the structural analysis of ground supported concrete slabs are presented. The principles of limit state design in terms of strength and serviceability are implemented....
Characterizing Mode I Fatigue Delamination of Composite Materials
Evaluation of two techniques to characterize fatigue delamination using the double cantilever beam (DCB) specimen are presented. The two techniques were the delamination growth onset (G-N)...
Acoustic Emission Source Locations in Concrete
The location of acoustic emission (AE) sources can potentially provide information on the fracture process zone in brittle materials such as concrete. Typical AE experiments generate very...
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,...
Cement and Concrete Characterization by Scanning Electron Microscopy
The scanning electron microscope (SEM) is a powerful tool for the microstructural and chemical characterization of cement and concrete. Imaging techniques such as secondary electron, 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...
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,...
Deformation of Concrete Due to Drying
The deformation of drying concrete is numerically investigated considering the effect of random arrangement of coarse aggregates. The result indicates that a part of the statistical variation...
A Phenomenological Approach to Physico Chemical Phenomena Coupled with Damage in Massive Concrete
This paper presents the first experiments which have been done to support the bases of a thermomechanical model coupled with damage and to identify the characteristics parameters needed...
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