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...
Softening Models for Concrete: Stability and Uniqueness
A microstructurally-based, numerically oriented, fracture-induced softening model for concrete is presented. Rate-dependent evolution equations for microcrack nucleation, growth, and coalescence...
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...
Strain-Based Damage Deactivation in Concrete
Motivated by the 'mode I' microcrack opening and closing mechanism, a procedure for the deactivation of the damage is developed. Strain based projection operators are used to negate the...
Nonlinear Analysis of Strain-Softening Damage under Monotonic and Cyclic Loading
The paper reviews the modeling of damage by the microplane model and presents extensions required for cyclic loading. The general microplane constitutive model is implemented in a three-dimensional...
Mechanics of Growing Deformable Solids: A Review
An attempt is undertaken to summarize the contemporary knowledge in mechanics of deformable solids of accruing mass. A general mathematical model of an abstract growing deformable solid...
Estimating Damage and its Influence on Fracture Toughness
To estimate damage in a quantitative manner, a technique used whereby six values of linear strain are measured on a material element as a function of hydrostatic pressure. The high precision...
Nonlinear Geometric and Material Considerations in Shell Structures
A geometrically and materially nonlinear static shell theory allowing large displacements, rotations, and strains with parabolic shear is developed. The theory is cast into a total Lagrangian...
Wave Propagation in a Nonlocal Strain-Softening Continuum
The problem of wave propagation in a nonlocal strain softening solid is first discussed analytically. It is demonstrated that 'loading' waves can still propagate in the strain softening...
On the Role of Dispersive Waves in Strain-Softening Media
Wave propagation in strain-softening continua is investigated numerically and analytically. It is argued that localisation which typically acts as a precursor of failure, can only be described...
Applications of Viscoelastic Damper to Jointed Structures for Seismic Mitigation
Some structures, such as dams, are built with contraction joints that might carry some small tensile stresses. Such joints are expected to open and close during an earthquake. That will...
An Evaluation Study of Modified Mohr-Coulomb and Cap Models
Two failure criteria, namely Mohr-Coulomb and cap models, are considered in this paper with some modifications. Mohr-Coulomb theory is applied to concrete after stress and strain cut-offs...
Micromechanics Based Design for Pseudo Strain-Hardening in Cementitious Composites
Micromechanical model constructed on the basis of fracture mechanics and fiber bridging provides a means of selection of fiber, matrix and interface property combinations for which short...
Computational Gradient Plasticity
The inclusion of higher-order deformation gradients is of paramount importance for properly describing strain localization within the framework of continuum mechanics. In this contribution...
Stochastic Mixed Finite Difference Method
Some aspects of numerical solutions of stochastic mechanics problems are considered. The Finite Difference method for discretization of stochastic continuous media problems is discussed....
A Cumulative Failure Criterion of Concrete Under Uniaxial Dynamic Compressive Loading
It has been previously reported that the strength and critical strain of concrete under impact increase with strain rate, but neither of them can predict failure. A cumulative damage parameter...
Mechanical Properties of High Performance Concretes
This paper presents some of the initial results of a 4-year research project on mechanical properties of high performance concretes with particular reference to highway applications. High...
Stochastic Finite and Boundary Elements
The random coefficients in partial differential equations, which govern the responses of stochastic thermo-mechanical systems, (Dasgupta, 1991), pose a computational challenge. The large...
Finite/Macroelement Meshes in Neural Rat Growth
The well known attributes of neural rat growth during 7 to 14 days postnatally are used to demonstrate the decrease in calculated growth discontinuities with macro, as opposed to finite,...
Form Comparison Without Anatomical Landmarks
The mathematical basis for various morphometric interpolating techniques is discussed. A technique, which enables analysis of biological forms without homologous anatomical landmarks,...
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