Protective ultra-thin barrier lms gather increasing economic interest for controlling permeation and di usion from the biological surrounding in implanted sensor and electronic devices in future medicine. Thus, the aim of this work was the investigation of the lm thickness in uence on the gas permeation barrier of ultra-thin, cytocompatible tetrahedral amorphous carbon (ta-C:H) lms on polyimide...

We employ a genetic algorithm to maximize the energy dissipated per unit areal density in laminates composed of layers of poly-methyl-metha-acrylate (PMMA), adhesive and polycarbonate (PC) impacted at low velocity by a rigid hemi-spherical nosed cylinder. Sources of energy dissipation considered are plastic deformations of the PC and the PMMA, cracking of the PMMA, viscous deformations of the a...

A new approach for generating stress-constrained topological designs in continua is presented. The main novelty is in the use of elasto-plastic modeling and in optimizing the design such that it will exhibit a linear-elastic response. This is achieved by imposing a single global constraint on the total sum of equivalent plastic strains, providing accurate control over all local stress violation...

Background: An electronic device consists of electronic components attached on a circuit board. Reliability of such a device is limited to fatigue properties of the components as well as of the board. Printed circuit board (PCB) consists of conducting traces and vertical interconnect access (via) out of copper embedded in a composite material. Usually the composite material is fiber reinforced ...

in this research a new approach is proposed for elasto-plastic analysis of structures with truss elements. this method covers both perfectly plastic and hardening properties. the proposed technique uses substituting virtual loads instead of modifying the stiffness matrix. to solve this kind of problems, complementary programming is utilized. numerical examples demonstrate that elastoplastic ana...

Designing the microstructure of Fe-Ni permalloy by additive manufacturing (AM) opens new avenues to tailor materials' magnetic properties. Yet, AM-produced parts suffer from spatially inhomogeneous thermal-mechanical and responses, which are less investigated in terms process simulation modeling schemes. Here we present a powder-resolved multiphysics-multiscale scheme for describing hysteresis ...

In this note we investigate the question of higher regularity up to the boundary for quasilinear elliptic systems which origin from the time-discretization of models from infinitesimal elasto-plasticity. Our main focus lies on an elasto-plastic Cosserat model. More specifically we show that the time discretization renders H-regularity of the displacement and H-regularity for the symmetric plast...

The stress integration procedure proposed by Eterovic and Bathe [Inr. J. numer. Merh. Engng 30, 1099-l 114 (1990).] is studied in detail. The elasto-plasticity formulation is based on the use of the total logarithmic strains and Cauchy stresses, and the Euler backward method of time integration. The accuracy of the procedure is assessed in the solution of various analysis problems and is compar...

We analyze the initiation and development of a shear band in a thermo-elasto-viscoplastic body deformed in simple shear by tangential velocity and heat flux prescribed at the outer bounding surfaces. Unlike previous studies no defect is introduced to initiate a shear band. The prescribed heat flux acts as a defect, and the shear band initiation time depends upon it. 2005 Elsevier Ltd. All right...

In this Part I, of a two-part paper, we present a detailed continuum-mechanical development of a thermomechanically coupled elasto-viscoplasticity theory to model the strain rate and temperature dependent largedeformation response of amorphous polymeric materials. Such a theory, when further specialized (Part II) should be useful for modeling and simulation of the thermo-mechanical response of ...