[Le comportement de la déformation plastique pour un oscillateur élastique-parfaitement-plastique excité par un bruit blanc]
Des résultats expérimentaux en sciences de lʼingénieur ont montré que, pour un oscillateur élasto-plastique-parfait excité par un bruit blanc, la déformation plastique et la déformation totale ont une variance, qui asymptotiquement, croît linéairement avec le temps avec le même coefficient. Dans ce travail, nous prouvons ce résultat et nous caractérisons le coefficient de dérive. Notre étude repose sur une inéquation variationnelle stochastique gouvernant lʼévolution entre la vitesse de lʼoscillateur et la force de rappel non-linéaire. Nous définissons alors le comportement en cycles longs du processus de Markov solution de lʼinéquation variationnelle stochastique qui est le concept clé pour obtenir le résultat. Une question importante en sciences de lʼingénieur est de calculer ce coefficient. Les résultats numériques confirment avec succès notre prédiction théorique et les études empiriques faites par les ingénieurs.
For decades, a vast amount of research effort in experimental engineering together with numerical simulations has been devoted to the study of the plastic deformation and total deformation of elasto-perfectly-plastic (EPP) oscillators. All of these results reveal that both the plastic and total deformations of an EPP oscillator, being excited by a white noise, have variances that increase linearly with time and share a common asymptotic growth rate. Before our present work, there was no apparent theoretical justification on this empirical observation. In this paper, we use a stochastic variational inequality (SVI) for the modeling of the evolution between the velocity of an EPP oscillator and its non-linear restoring force; and this modeling has already been justified in some previous works of the authors. By introducing the novel notion of long cycle behavior of the Markovian solution of the corresponding SVI, we first establish a mathematical explanation for the empirical observation and characterize the mentioned asymptotic growth rate in terms of certain stopping times read off from the trajectory; secondly, we show an effective method on computing this asymptotic growth rate, which has been a long lasting challenging question to engineers. Finally numerical simulation is provided to illustrate the notable agreement between our theoretical prediction and empirical studies in the engineering literature.
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@article{CRMATH_2012__350_17-18_853_0,
author = {Bensoussan, Alain and Mertz, Laurent and Yam, S.C.P.},
title = {Long cycle behavior of the plastic deformation of an elasto-perfectly-plastic oscillator with noise},
journal = {Comptes Rendus. Math\'ematique},
pages = {853--859},
publisher = {Elsevier},
volume = {350},
number = {17-18},
year = {2012},
doi = {10.1016/j.crma.2012.09.020},
language = {en},
url = {http://www.numdam.org/articles/10.1016/j.crma.2012.09.020/}
}
TY - JOUR AU - Bensoussan, Alain AU - Mertz, Laurent AU - Yam, S.C.P. TI - Long cycle behavior of the plastic deformation of an elasto-perfectly-plastic oscillator with noise JO - Comptes Rendus. Mathématique PY - 2012 SP - 853 EP - 859 VL - 350 IS - 17-18 PB - Elsevier UR - http://www.numdam.org/articles/10.1016/j.crma.2012.09.020/ DO - 10.1016/j.crma.2012.09.020 LA - en ID - CRMATH_2012__350_17-18_853_0 ER -
%0 Journal Article %A Bensoussan, Alain %A Mertz, Laurent %A Yam, S.C.P. %T Long cycle behavior of the plastic deformation of an elasto-perfectly-plastic oscillator with noise %J Comptes Rendus. Mathématique %D 2012 %P 853-859 %V 350 %N 17-18 %I Elsevier %U http://www.numdam.org/articles/10.1016/j.crma.2012.09.020/ %R 10.1016/j.crma.2012.09.020 %G en %F CRMATH_2012__350_17-18_853_0
Bensoussan, Alain; Mertz, Laurent; Yam, S.C.P. Long cycle behavior of the plastic deformation of an elasto-perfectly-plastic oscillator with noise. Comptes Rendus. Mathématique, Tome 350 (2012) no. 17-18, pp. 853-859. doi : 10.1016/j.crma.2012.09.020. http://www.numdam.org/articles/10.1016/j.crma.2012.09.020/
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☆ This research in the Note was supported by WCU (World Class University) program through the National Research Foundation of Korea funded by the Ministry of Education, Science and Technology (R31-20007) and by the Research Grants Council of HKSAR (PolyU 5001/11P). This research was partially supported by a grant from CEA, Commissariat à lʼénergie atomique and by the National Science Foundation under grant DMS-0705247. A large part of this work was completed while the second author was visiting the University of Texas at Dallas and the Hong-Kong Polytechnic University. We wish to thank warmly these institutions for the hospitality and support. The third author also expresses his gratitude to the generous support from HKGRF 502408.
