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To understand and model the thermomechanical response of AL-6XN stainless steel, uniaxial compression tests are performed on cylindrical samples, using an Instron servohydraulic testing machine and UCSD's enhanced Hopkinson technique. True strains exceeding 40% are achieved in these tests, over the range of strain rates from 0.001=s to about 8000=s, and at(More)
The repeated fracture–healing characteristics of 2MEP4F polymer, a cross-linked polymer based on Diels–Alder cycloaddition, are systematically and quantitatively evaluated using a sample geometry that allows for controlled incremental crack growth so that the cracked sample remains in one piece after the test, improving our ability to realign the fracture(More)
A method for homogenization of an elastic composite with periodic microstructure is presented, focusing on the Floquet-type elastic waves. The resulting homogenized frequency-dependent elasticity and mass density then automatically satisfy the overall conservation laws and by necessity produce the exact dispersion relations. It is also shown that the(More)
An ionic polymer-metal composite (IPMC) consisting of a thin perfluorinated ionomer (usually, Nafion or Flemion) strip, platinum, and/or gold plated on both faces and neutralized by a certain amount of appropriate cations undergoes large bending motion when, in a hydrated state, a small electric field is applied across its thickness. When the same membrane(More)
To characterize the thermomechanical response, especially the superelastic behavior of NiTi shape-memory alloys (SMAs) at various temperatures and strain rates, we have performed a series of both quasi-static and dynamic uniaxial compression tests on cylindrical samples, using an Instron servohydraulic testing machine and UCSD's enhanced Hopkin-son(More)
The minimization of the radial release effects in the recovery configurations of plate impact experiments is essential for accurate postmortem microstructural investigations. The present study evaluates the results of several three-dimensional finite-element simulations involving different plate geometries. The study examines combinations of circular,(More)
a r t i c l e i n f o a b s t r a c t Stress-wave propagation in solids can be controlled through imposing a gradual change of anisotropy in the material elasticity tensor. In this study, a transversely isotropic material is incorporated with a smoothly varying axis of anisotropy. It is shown that if this axis initially coincides with the stress-wave(More)
Ionic polymer-metal composites (IPMCs) consist of a perfluorinated ionomer membrane (usually Nafion ® or Flemion ®) plated on both faces with a noble metal such as gold or platinum and neutralized with a certain amount of counterions that balance the electrical charge of anions covalently fixed to the membrane backbone. IPMCs are electroactive materials(More)
A method for the homogenization of a layered elastic composite is presented. It allows direct, consistent, and accurate evaluation of the averaged overall frequency-dependent dynamic material constitutive relations without the need for a point-wise solution of the field equations. When the spatial variation of the field variables is restricted by Bloch-form(More)