Wyniki wyszukiwania - BazTech

Ograniczanie wyników

2 Archives of Civil and Mechanical Engineering

Znaleziono wyników: 2

Liczba wyników na stronie

Wyniki wyszukiwania

Sortuj według:

Ogranicz wyniki do:

Special kind of multimaterial topology optimization

Kutyłowski R., Szwechłowicz M.

Archives of Civil and Mechanical Engineering

2013

Vol. 13, no. 3

334--344

Topology optimization provides an answer to the question how to distribute the available material in a design domain. The optimization process (usually aided by postprocessing) results in a material-void distribution, also called (in terms of relative density) a 0/1 distribution, which is graphically represented as a black-and-white distribution. Assuming that the optimum solution is such for which the energy accumulated in the construction is minimum, an optimum construction topology was arrived at. In this solution the material is in the same areas in which it would be for a 0/1 solution, however the relative density in the design domain is not only equal to zero or one, but also assumes values between zero and one (the values are closer to one than to zero). In this way a construction whose material properties vary from point to point in a way directly dependent on the effort of the material, i.e. adequately to the needs arising from the necessity of carrying the load by the construction, was obtained. Thus through the use of a proper optimization approach and the proposed algorithm a construction built from a material with graded mechanical properties was obtained.

Topology optimisation as a tool for obtaining a multimaterial structure

Kutyłowski R., Rasiak B., Szwechłowicz M.

Archives of Civil and Mechanical Engineering

2011

Vol. 11, no 2

391-409

Topology optimisation problem solutions are generally presented in such a way that ultimately a material/ void (1/0) distribution is obtained in the design domain. For this purpose, filtering techniques are usually used or post-processing is applied in the optimisation process. As a rule, the result is quasi-optimal since no minimum value of the objective functional is then obtained. In this study an optimal body topology is determined. Its characteristic feature is that besides normal material and voids there is a material with poorer and varied parameters in the design domain. The latter material is often distributed in the form of a layer around the axis of each member of the construction and gets weaker with the distance from the axis. This means that the construction is multimaterial and individual layers can be distinguished in its members. In this sense, the construction is a layered one. The compliance functional is minimized under constraints imposed on the body mass, which means that the initially available mass is kept constant throughout the optimisation process. Looking for the functional stationary point one gets the following dependence: material density in a particular material point for the considered iteration is proportional to the strain energy accumulated in this point. A discretely updated Young modulus is used in the successive steps in the construction of stiffness matrices. The update for the individual material points in the successive iterations is based on the strain energy distribution in the previous step. The problem was solved numerically using FEM and identifying body material points with finite elements.

Rozwiązania problemu optymalizacji topologii są najczęściej przedstawiane w ten sposób, że ostatecznie w obszarze projektowym mamy do czynienie z rozkładem typu materiał - pustka. W pracy wykazano, że rzeczywista optymalna konstrukcja to konstrukcja warstwowa składająca się z różnych materiałów, w której twardy rdzeń pręta otoczony jest coraz słabszymi warstwami. Zastosowano podejście energetyczne minimalizując funkcjonał podatności przy więzach nałożonych na masę ciała. Implementację numeryczną wykonano przy wykorzystaniu metody elementów skończonych.