Development of a Constitutive Model for Impact Limiters
A constitutive model is being developed for 'impact limiter' materials such as aluminum honeycombs and polyurethane foams. Among other applications, these materials...
Localized Collapse of Shells of Revolution
A local-global methodology is presented to treat the problems of localized collapse of shells of revolution. The strategy consists of employing two dimensional general shell elements in...
Finite Element Stress Analysis of a Spinal Segment
A large number of factors need to be determined to understand the biomechanics of a surgical procedure about the lumbar spine. Some of these factors are amenable to experimental investigations...
A Theory of Porous Plasticity at Low Triaxiality
A simple multiaxial theory of plasticity which is capable of taking into account the influence of pore shape at low concentration is developed for an isotropic porous material at a triaxiality...
Influence of Finite Deformations in the Stress-Strain Modelling of Granular Media
An incremental formulations of the stress-strain law is presented for quasi-static deformation of granular solids. The stress-strain relationship is derived for an element of granular...
Three-Dimensional Finite Element Analysis of Stress and Activation in the Heart
A finite element (FE) method has been developed for three-dimensional (3D) analysis of stress distributions and activation patterns in the left and right ventricles of the canine heart....
Penetration Tests in a Particulate Calibration Chamber
A numerical technique which couples discrete element method with boundary element method has been developed to simulate a two dimensional particulate assembly. Soil particles in the near...
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...
Stochastic Strain-Displacement Matrices for Finite Elements with Random Constitution
A prescribed correlated random field for elastic moduli furnishes an associated population of stochastic shape functions at the element level. The principle of deterministic tractions,...
Earth Pressure Acting on Buried Flexible Pipes in Centrifuged Models
Distributions of both normal and tangential earth pressures acting on three flexible model pipes having different wall thicknesses were successfully measured in centrifuge model tests....
Impact Strain Investigations on Tetrapods: Results of Dry and Hydraulic Tests
Development of a Plane-Strain Device for Soft Rock
Work is now in progress to build a plane-strain apparatus for 'soft' (unconfined compressive strenghts below 35 MPa) rock and concrete, based upon a passive,...
Field Installation of Strain Gaged Geotextiles
High-strength polyester geotextiles were used in two major Corps of Engineers projects: Wilmington Harbor, Del. and New Bedford, Mass. To verify design assumptions and as part of monitoring...
A Microplane Constitutive Model for Soils
A microplane model for the inelastic behavior of soils is presented. The microscopic constitutive equations are defined independentely for a set of microplanes covering all possible orientations,...
Rate Effects on Fracture of Concrete
An analytical and experimental investigation of mode I (tensile and mixed mode (combined tensile and shear) fracture of concrete subjected to impact loading was conducted. The rate of...
Geocomposite Waste Cell Capping System for Steep Slopes
Several geosynthetics manufacturers have developed new products with high surface friction characteristics for capping steep slopes. One such product has been developed that will satisfy...
Drying and Shrinkage of Concrete: The Case of Massive Parts
The natural drying of concrete induces a number of intense mechanical effects on the structures. These various effects are of importance to engineers: in the design stage (estimate of...
Localization Instabilities Due to Damage and Fracture Propagation: Application to Tensile Specimens
In recent research it has become clear that localization of damage due to strain softening as well as propagation of interactive cracks can result in bifurcations of the loading path characterized...
A Hardening/Softening Model of Snow for Snow-Working Processes
Optimization of Cable Prestresses of Cable Stayed Bridges Based on Minimum Strain Energy Criterion
In this study, an attempt is made to determine the optimum cable prestresses based on the strain energy criterion. The validity of the strain energy criterion on the optimum cable prestresses...
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