Now showing items 1-20 of 26

• #### Calibration Procedures for a Computational Model of Ductile Fracture ﻿

(Elsevier, 2010)
A recent extension of the Gurson constitutive model of damage and failure of ductile structural alloys accounts for localization and crack formation under shearing as well as tension. When properly calibrated against a ...
• #### Cohesive Traction-Separation Laws for Tearing of Ductile Metal Plates ﻿

(Elsevier, 2012)
The failure process ahead of a mode I crack advancing in a ductile thin metal plate or sheet produces plastic dissipation through a sequence of deformation steps that include necking well ahead of the crack tip and shear ...
• #### Comparison of Mechanical Properties of Ni[sub]3Al Thin Films in Disordered FCC and Ordered L1[sub]2 Phases ﻿

(Elsevier Science B.V., Amsterdam, 2001)
We report the results of several experiments isolating the effect of long-range order on mechanical properties of intermetallic compounds. Kinetically disordered FCC Ni<sub>3</sub>Al (Ni 76%) thin films were produced by ...
• #### Concepts for Enhanced Energy Absorption Using Hollow Micro-Lattices ﻿

(Elsevier, 2010)
We present a basic analysis that establishes the metrics affecting the energy absorbed by multilayer cellular media during irreversible compaction on either a mass or volume basis. The behaviors at low and high impulse ...
• #### A Critical Assessment of Theories of Strain Gradient Plasticity ﻿

(Elsevier, 2009)
Theories to extend plasticity to the micron scale have been in existence for over a decade, complemented by a growing body of experimental data. Here, materials and mechanics aspects of two prominent strain gradient theories ...
• #### Crossover Patterning by the Beam-Film Model: Analysis and Implications ﻿

(Public Library of Science, 2014)
Crossing-over is a central feature of meiosis. Meiotic crossover (CO) sites are spatially patterned along chromosomes. CO-designation at one position disfavors subsequent CO-designation(s) nearby, as described by the ...
• #### Deformation and Fracture of Impulsively Loaded Sandwich Panels ﻿

(Elsevier, 2013)
Light metal sandwich panel structures with cellular cores have attracted interest for multifunctional applications which exploit their high bend strength and impact energy absorption. This concept has been explored here ...
• #### From Wrinkles to Creases in Elastomers: The Instability and Imperfection-Sensitivity of Wrinkling ﻿

(The Royal Society, 2012)
The stability of the wrinkling mode experienced by a compressed half-space of neo-Hookean material is investigated using analytical and numerical methods to study the post-bifurcation behaviour of periodic solutions. It ...
• #### Generalizing $J_2$ Flow Theory: Fundamental Issues in Strain Gradient Plasticity ﻿

(Springer Verlag, 2012)
It has not been a simple matter to obtain a sound extension of the classical $J_2$ flow theory of plasticity that incorporates a dependence on plastic strain gradients and that is capable of capturing size-dependent ...
• #### The Influence of Transient Thermal Gradients and Substrate Constraint on Delamination of Thermal Barrier Coatings ﻿

(American Society of Mechanical Engineers, 2013)
A systematic study of factors affecting the delamination energy release rate and mode mix of a thermal barrier coating attached to a substrate is presented accounting for the influence of thermal gradients combined with ...
• #### Knockdown Factors for Buckling of Cylindrical and Spherical Shells Subject to Reduced Biaxial Membrane Stress ﻿

(Elsevier, 2010)
Cylindrical shells under uniaxial compression and spherical shells under equi-biaxial compression display the most extreme buckling sensitivity to imperfections. In engineering practice, the reduction of load carrying ...
• #### Lifetime Assessment for Thermal Barrier Coatings: Tests for Measuring Mixed Mode Delamination Toughness ﻿

(John Wiley & Sons, 2011)
Mechanisms leading to degradation of the adherence of thermal barrier coatings (TBC) used in aircraft and power generating turbines are numerous and complex. To date, robust methods for the lifetime assessment of coatings ...
• #### Localized Ridge Wrinkling of Stiff Films on Compliant Substrates ﻿

(Elsevier, 2012)
Wrinkling of thin stiff films on thick compliant elastomeric substrates subject to plane strain compression is considered for cases in which the substrate is pre-stretched prior to film attachment. Advanced wrinkling modes ...
• #### Nanopore Fabrication in Amorphous Si: Viscous Flow Model and Comparison to Experiment ﻿

(American Institute of Physics, 2010)
Nanopores fabricated in free-standing amorphous silicon thin films were observed to close under 3 keV argon ion irradiation. The closing rate, measured in situ, exhibited a memory effect: at the same instantaneous radius, ...
• #### Necking Modes in Multilayers and their Influence on Tearing Toughness ﻿

(SAGE Publications, 2013)
Periodic bifurcation modes that occur in ductile multilayered plates or sheets stretched in plane strain tension are analyzed to reveal whether necks are likely to localize at the scale of the thickness of individual layers ...
• #### Numerical Simulation of Cropping ﻿

(ASME International, 2014)
Cropping is a cutting process whereby opposing aligned blades create a shearing failure by exerting opposing forces normal to the surfaces of a metal sheet or plate. Building on recent efforts to quantify cropping, this ...
• #### Periodic Patterns and Energy States of Buckled Films on Compliant Substrates ﻿

(Elsevier, 2011)
Thin stiff films on compliant elastic substrates subject to equi-biaxial compressive stress states are observed to buckle into various periodic mode patterns including checkerboard, hexagonal and herringbone. An experimental ...
• #### Response of Metallic Pyramidal Lattice Core Sandwich Panels to High Intensity Impulsive Loading in Air ﻿

(Elsevier, 2011)
Small scale explosive loading of sandwich panels with low relative density pyramidal lattice cores has been used to study the large scale bending and fracture response of a model sandwich panel system in which the core has ...
• #### Ridge Localizations and Networks in Thin Films Compressed by the Incremental Release of a Large Equi-biaxial Pre-stretch in the Substrate ﻿

(Wiley-Blackwell, 2014)
Two-dimensional ridge structures are induced by equi-biaxial compression with large equi-biaxial pre-stretch in a thin film by using a micro-fluidics technique. Whereas wrinkles tend to be uniformly distributed, ridges are ...
• #### The Role of Nonlinear Substrate Elasticity in the Wrinkling of Thin Films ﻿

(The Royal Society, 2013)
The role of substrate nonlinearity on the stability of wrinkling of thin films bonded to compliant substrates is investigated within the initial post-bifurcation range when wrinkling first emerges. A fully nonlinear ...