We review the classical theory of static and quasi-static plasticity in an abstract framework of convex analysis. It can be shown that the extended use of orthogonal projections onto closed convex sets simplifies the analysis substantially. We present new characterizations of the primal problem in plasticity. The abstract setting is applied to problems in perfect plasticity and to plasticity wi...

Invisible cloaking is one of the major outcomes of the metamaterial research, but the practical potential, in particular for high frequencies (for example, microwave to visible light), is fatally challenged by the complex material properties they usually demand. On the other hand, it will be advantageous and also technologically instrumental to design cloaking devices for applications at low fr...

The paper presents a numerical implementation of a novel approximation scheme for Griffith’s theory of brittle fracture recently proposed in [1]. The total potential energy of a brittle body (including bulk and surface terms) is variationally approximated by a family of functionals, depending on a small penalty parameter ε. The (two-field) approximating functionals have as arguments the displac...

This paper considers the performance analysis of coded OFDM systems over frequency-selective fading channels. It is shown that both the random coding upper bounds and the strong converse lower bounds of a coded OFDM system converge to the channel outage probability for large OFDM block lengths. Thus primary attention is given to the analysis of the outage probability, which is taken as the opti...

An instrumental electrode model (IEM) capable of describing the performance of electrical impedance tomography (EIT) systems in the MHz frequency range has been proposed. Compared with the commonly used Complete Electrode Model (CEM), which assumes ideal front-end interfaces, the proposed model considers the effects of non-ideal components in the front-end circuits. This introduces an extra bou...

To solve the problem of resonance during quasi-static calibration of high-g accelerometers, we deduce the relationship between the minimum excitation pulse width and the resonant frequency of the calibrated accelerometer according to the second-order mathematical model of the accelerometer, and improve the quasi-static calibration theory. We establish a quasi-static calibration testing system, ...

Assessing the behavior of composite structures which are subjected to impact loads is one of the important subjects in the field of mechanical sciences. Using thin-walled tubes which collapsed and absorbed the impact energy is a well-known method to prevent damages to the other parts of the structures. In this paper, deformations, crushing length, peak load, mean force and energy absorption cap...

We investigate classes of shear-free cosmological dust models with irrotational fluid flows within the framework $f(T)$ gravity. In particular, we use $1 + 3$ covariant formalism and present linearised evolution constraint equations describing such models. then derive integrability conditions a consistent field these quasi-Newtonian universes in gravitational theory. Finally, for density veloci...

Most of the existing literature on performance evaluation of fading channels is concentrated on either the symbol error rate of the links, or the outage capacity. We present in this technical report approximation techniques for the packet error rate of quasi-static fading channels. This model applies when the channel coherence time is larger than the signaling time and leads to multiple symbols...