We study three-dimensional finite transient deformations of transparent poly-methyl-methacrylate (PMMA)/adhesive/polycarbonate (PC) laminates impacted at low speed by a hemispherical nosed rigid cylinder using the commercial finite element (FE) software LS-DYNA. The two glassy polymers PMMA and PC are modeled as thermo-elasto-visco-plastic materials by using the constitutive relation proposed b...

The viscoelastic behavior of polymer composites decreases the deployment force and the postdeployment shape accuracy of composite deployable space structures. This paper presents a viscoelastic model for single-ply cylindrical shells (tape springs) that are deployed after being held folded for a given period of time. The model is derived from a representative unit cell of the compositematerial,...

Negative characteristics are given throughout for the logarithms of the trigonometric functions, when the corresponding numbers are less than unity. This departure from the usual custom of increasing the logarithms by 10 can hardly be regarded as an improvement. The greatest possible care has been taken to secure the accuracy of the tables ; and in this respect they may be greatly commended. Th...

In this paper a Prony-like method for non-uniform sampling is proposed. The unknown parameters are estimated on the base of a new linear regression equation which uses filtered signals obtained directly from the measurements. The approach uses the derivative method in the frequency domain yielding exact formula in terms of multiple integrals of the signal, when placed in the time domain. These ...

Prony 's method is employed in spectral domain estimation to model epilepsy seizure from human 's Electroencephalograph (EEG).This method assumes that the original signal is a sum of damped complex exponential sinusoids. The method has the best frequency resolution compared to Auto Regression (AR) parametric methods. Modeling of the ictal EEG Epilepsy signal is based on the poles of the signal....

In this paper we develop rational discrete-time approximations (IIR filters) to continuous fractional-order integrators and differentiators of type sα, α ∈ R. For that, it is proposed the adoption of the techniques of Padé, Prony and Shanks usually applied in the signal modelling of deterministic signals. These methods yield suboptimal solutions to the problem which only requires finding the so...

A dynamic equivalent black-box model, based on Prony analysis is presented in this paper. The proposed model is suitable for dynamic studies of microgrids, considering changes in the active and reactive power, bus voltages, currents and frequency. The developed model is evaluated using simulation results obtained from a medium voltage microgrid and test measurements recorded in a low voltage mi...

Biological tissues often experience drastic changes in their microstructure due to their pathophysiological conditions. Such microstructural changes could result in variations in mechanical properties, which can be used in diagnosing or monitoring a wide range of diseases, most notably cancer. This paves the avenue for non-invasive diagnosis by instrumented palpation although challenges remain ...

We propose a constitutive relation for finite deformations of nearly incompressible isotropic viscoelastic rubbery adhesives assuming that the Cauchy stress tensor can be written as the sum of elastic and viscoelastic parts. The former is derived from a stored energy function and the latter from a hereditary type integral. Using Ogden’s expression for the strain energy density and the Prony ser...