research
Article: Viscous Theory for the Vibrations of Coaxial Cylinders: Analytical Formulas for the Fluid Forces and the Modal Added Coefficients
This article addresses the small-amplitude forced beam vibrations of two coaxial finite-length cylinders separated by a viscous Newtonian fluid. A new theoretical approach based on an Helmholtz expansion of the fluid velocity vector is carried out, leading to a full analytical expression of the fluid forces and subsequently of the modal added mass and damping coefficients. Our theory shows that the fluid forces are linear combinations of the Fourier harmonics of the vibration modes.
Distal and non-symmetrical crack nucleation in delamination of plates via dimensionally-reduced peridynamics
R Cavuoto, A Cutolo, K Dayal, L Deseri *, M Fraldi*, Journal of the Mechanics and Physics of Solids 172 (2023) 105189 https://doi.org/10.1016/j.jmps.2022.105189
Abstract
Exploiting the framework of peridynamics, a dimensionally-reduced formulation for plates is developed that allows for the through-thickness nucleation and growth of fracture surfaces,
Dynamic Hardness Evolution in Metals from Impact Induced Gradient Dislocation Density
Dear Colleagues,
I invite you to read our recent publication on Acta Materialia on the dynamic hardness evolution in metals.
Finite Extension of Accreting Nonlinear Elastic Solid Circular Cylinders
In this paper we formulate and solve the initial-boundary value problem of accreting circular cylindrical bars under finite extension. We assume that the bar grows by printing stress-free cylindrical layers on its boundary cylinder while it is undergoing a time-dependent finite extension. Accretion induces eigenstrains, and consequently residual stresses. We formulate the anelasticity problem by first constructing the natural Riemannian metric of the growing bar. This metric explicitly depends on the history of deformation during the accretion process.
PhD position at Uppsala University: Elasto-hydro-dynamic analysis of architectured materials
CIM (Centre for Interdisciplinary Mathematics) at Uppsala University in Sweden is recruiting PhD students for three of the seventeen projects announced. One of the announced projects are proposad by us to address elasto-hydro-dynamic analysis of architectured materials. If interested, please consider applying:
https://www.uu.se/en/about-uu/join-us/details/?positionId=596823
Reconfigurable enhancement of actuation forces by engineered losses in non-Hermitian metamaterials
Dear Colleagues,
I invite you to read our recent Extreme Mechanics Letters paper presenting a novel viewpoint on enhancing emissivity near exceptional point singularities in a non-Hermitian metamaterial. We present the experiments and numerical modeling in an elastodynamic framework--where the actuation forces from an actuator are enhanced by coupling to a passive dissipative non-Hermitian metamaterial--and present the theory further generalized and applicable to other physical frameworks from acoustics to optics and microwaves.
Modeling SEBM Process of Tantalum Lattices
Selective electron beam melting (SEBM) is one of the popular powder-bed additive manufacturing (AM) technologies, of which there have been extensive studies employing numerical simulations to investigate the thermo-physical phenomena. A procedure for deducing thermo-physical properties of powders from bulk properties of tantalum is presented.
