Maks Oblak

TL;DR: In this article, the mathematical model of calculation of thermophysical properties for nanofluids on the basis of statistical nanomechanics is presented, and the analytical results obtained by statistical mechanics are compared with the experimental data and show relatively good agreement.

TL;DR: In this article, the authors developed a mathematical model where fundamental thermomechanical properties of state are functions of temperature such as modulus of elasticity, Poisson number, linear expansion coefficient, shear modulus and some other important thermodynamic properties.

TL;DR: In this paper, the incremental harmonic balance method with multiple time variables is developed for analysis of almost periodic oscillations in multi-degree-of-freedom dynamical systems with cubic nonlinearities, subjected to the external multi-tone excitation.

TL;DR: The paper presents an extended approach to non-linear first-order approximation of non- linear programming problems and it explains how to transform an approximate problem into a strictly convex one.

Abstract: The paper presents an approach to shape optimization of proportionally loaded elastic shell structures under stability constraints. To reduce the stability-related problems, a special technique is utilized, by which the response analysis is always terminated before the first critical point is reached. In this way, the optimization is always related to a precritical structural state. The necessary load-carrying capability of the optimal structure is assured by extending the usual formulation of the optimization problem by a constraint on an estimated critical load factor. Since limit points are easier to handle, the possible presence of bifurcation points is avoided by introducing imperfection parameters. They are related to an asymmetric shape perturbation of the structure. During the optimization, the imperfection parameters are updated to get automatically the ‘worst-case’ pattern and amplitude of the imperfection. Both, the imperfection parameters and the design variables are related to the structural shape via the design element technique. A gradient-based optimizer is employed to solve the optimization problem. Three examples illustrate the proposed approach. Copyright © 2007 John Wiley & Sons, Ltd.