Wyniki wyszukiwania - BazTech

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Consideration of the uncertainty in the dimensioning of a gearbox of a wind turbine

Trabelsi Hassen, Guizani Amir, Barkallah Maher, Hammadi Moncef, Hadrich Ayman

Journal of Theoretical and Applied Mechanics

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2021

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Vol. 59 nr 1

67--79

EN

The paper deals with the design approach of a subdefinite mechatronic system and focuses on the sizing stage of a gearbox of a wind turbine based on the interval computation method. Indeed, gearbox design variables are expressed by intervals to take into account the uncertainty in the estimation of these parameters. The application of the interval computation method allows minimizing the number of simulations and enables obtaining a set of solutions instead of a single one. The dynamic behavior of the gearbox is obtained using the finite element method. The challenge here is to get convergent results with intervals that reflect the efficiency of the applied method. Thus, several mathematical formulations have been tested in static study and evaluated in the case of a truss. Then the interval computation method was used to simulate the behavior of the wind turbine gearbox.

2

Consideration of uncertainties in the preliminary design case of an electromagnetic spindle

Trabelsi Hassen, Guizani Amir, Tounsi Dhouha, Hammadi Moncef, Barkallah Maher, Haddar Mohamed

Journal of Theoretical and Applied Mechanics

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2019

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Vol. 57 nr 4

821--832

EN

Modeling and evaluation of uncertainties constitute indeed one of the key points when making any decision. For this, designers have to compare the measured or calculated value with a range of permissible values in order to obtain a guaranteed design process. Thus, in this work, simulation of the dynamic behavior of an electromagnetic spindle was done based on the interval computation technique. Indeed, the use of this technique makes it possible to obtain a set of values for different design parameters of the spindle and, consequently, to avoid making several simulations which could make the system useless, expensive or ineffective. The proposed model is based on the combination of Matlab with ModelCenter. Matlab was used to model and simulate the system and ModelCenter to perform parametric studies to verify the influences of uncertainty on the dynamic behavior of the electromagnetic spindle and to determine the optimal design parameters.

3

Implementacja arytmetyki przedziałowej z wykorzystaniem rozszerzeń multimedialnych SSE oraz zmodyfikowanej metody dzielenia przedziałowego

Pilarek M.

Metody Informatyki Stosowanej

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2010

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nr 2 (23)

127-135

PL

Otrzymane wyniki badań potwierdzają, że zastosowanie rozszerzeń multimedialnych SSE w zagadnieniach związanych z arytmetyka˛ przedziałową znacznie skraca czas wykonywania obliczeń. Biblioteki Profil/BIAS oraz Boost, które zostały zaimplementowane z pominięciem rozszerzeń multimedialnych wykonują. obliczenia zdecydowanie dłużej. Zastosowanie innego formatu przechowywania przedziałów w pamięci ([a --- a]) oraz odpowiednie zmodyfikowanie operacji arytmetycznych pozwoliło na wykonywanie obliczeń bez ciągłej zmiany trybu zaokrąglania, co nie spowodowało utraty wydajności. Ponadto zastosowana w naszej implementacji zmodyfikowana metoda dzielenia bazująca na koncepcji metody "rozszerzonego przedziałowego zero" pozwala na uzyskiwanie znacznie węższych przedziałów, bez utraty wydajności.

EN

The aim of this paper is to show interval arithmetics implementation using single-instructionmultiple- data (SIMD) SSE (Streaming SIMD Extensions) multimedia instructions, and register set extensions. It was proven previously that SSE extensions can increase performance of interval calculations, since both interval bounds can be kept in one SSE register and all arithmetic operations can be done in parallel. In this work a new approach to the modified interval division is proposed based on the concept of “interval extended zero” method which is a part of this implementation. This method allows us to reduce the undesirable excess width effect. We show the results obtained for several randomly generated matrices using different algorithms (matrix-matrix multiplication, Gauss elimination) and compare them also with results obtained using other interval libraries.