Jean-Pierre Lambelin - Academia.edu (original) (raw)
Papers by Jean-Pierre Lambelin
Journal of sound and vibration, May 1, 2024
Communications in Nonlinear Science and Numerical Simulation, Jul 1, 2019
This paper presents experiments and numerical simulations of a nonlinear clampedclamped beam subj... more This paper presents experiments and numerical simulations of a nonlinear clampedclamped beam subjected to Harmonic excitations and epistemic uncertainties. These uncertainties are propagated in order to calculate the dynamic response of the nonlinear structure via a coupling between the Harmonic Balance Method (HBM) and a nonintrusive Polynomial Chaos Expansion (PCE). The system studied is a clamped-clamped steel beam. First of all, increasing and decreasing swept sine experiments are performed in order to show the hardening effect in the vicinity of the primary resonance, and to extract the experimental multi-Harmonic frequency response of the structure. Secondly, the Harmonic Balance Method (HBM) is used alongside a continuation process to simulate the deterministic response of the nonlinear clamped-clamped beam. Good correlations were observed with the experiments, on the condition of updating the model for each excitation level. Finally, the effects of the epistemic uncertainties on the variability of the nonlinear response are investigated using a non-intrusive Polynomial Chaos Expansion (PCE) alongside the Harmonic Balance Method (HBM). A new methodology based on a phase criterion was developed in order to allow the PCE analysis to be performed despite the presence of bifurcations in the nonlinear response. The efficiency and robustness of the proposed methodology is demonstrated by comparison with Monte Carlo simulations. Then, the stochastic numerical results are shown to envelope the experimental responses for each excitation level without the need for model updating, validating the nonlinear stochastic methodology as a whole.
Mechanical Systems and Signal Processing, Oct 1, 2021
The structure Harmony-Gamma is a metallic assembly representative of an industrial structure for ... more The structure Harmony-Gamma is a metallic assembly representative of an industrial structure for which the vibratory response is influenced by the apparition of nonlinear phenomena within two specific types of joints, the first corresponding to friction joints and the second to elastomer joints. The present study extends the previous work based on experiments and numerical simulations of the structure Harmony-Gamma subjected to harmonic vibrations [1]. More specifically, the nonlinear vibrational behaviour of the assembly subjected to random broadband excitations is studied. Broadband excitations are performed experimentally, in order to provide a first understanding of the nonlinear effect of both the friction and elastomer joints. Additionally, a global numerical methodology based on finite-element modelling and the use of the Harmonic Balance Method for the prediction of the nonlinear response of the Harmony-Gamma structure subjected to stochastic excitation is proposed. It is demonstrated that the use of a numerical model that has been validated against experimental tests can furthermore be used to achieve a refined understanding of the nonlinear phenomena and their origin.
Mechanical Systems and Signal Processing, Sep 1, 2018
This paper presents experiments and numerical simulations of a nonlinear clamped-clamped beam sub... more This paper presents experiments and numerical simulations of a nonlinear clamped-clamped beam subjected to Harmonic excitations and epistemic uncertainties. These uncertainties are propagated in order to calculate the dynamic response of the nonlinear structure via a coupling between the Harmonic Balance Method (HBM) and a non-intrusive Polynomial Chaos Expansion (PCE). The system studied is a clampedclamped steel beam. First of all, increasing and decreasing swept sine experiments are performed in order to show the hardening effect in the vicinity of the primary resonance, and to extract the experimental multi-Harmonic frequency response of the structure. Secondly, the Harmonic Balance Method (HBM) is used alongside a continuation process to simulate the deterministic response of the nonlinear clamped-clamped beam. Good correlations were observed with the experiments, on the condition of updating the model for each excitation level. Finally, the effects of the epistemic uncertainties on the variability of the nonlinear response are investigated using a non-intrusive Polynomial Chaos Expansion (PCE) alongside the Harmonic Balance Method (HBM). A new methodology based on a phase criterion was developed in order to allow the PCE analysis to be performed despite the presence of bifurcations in the nonlinear response. The efficiency and robustness of the proposed methodology is demonstrated by comparison with Monte Carlo simulations. Then, the stochastic numerical results are shown to envelope the experimental responses for each excitation level without the need for model updating, validating the nonlinear stochastic methodology as a whole.
HAL (Le Centre pour la Communication Scientifique Directe), May 15, 2017
-L'assemblage métallique étudié comprend neuf plots viscoélastiques en élastomère. La réponse vib... more -L'assemblage métallique étudié comprend neuf plots viscoélastiques en élastomère. La réponse vibratoire est influencée par le comportement non linéaire des plots. Un modèle élément fini de l'assemblage complet ainsi qu'un modèle de non-linéarité empirique issu d'essais unitaires sur des plots viscoélastiques seuls sont proposés. La méthode de simulation utilisée se base sur une réduction de modèle et une résolution par la méthode d'équilibrage harmonique incrémentale. Dans un second temps, la réponse dynamique non linéaire en présence d'incertitudes est proposée par l'intermédiaire du Chaos Polynomial non intrusif. Des comparaisons essais-calculs à l'échelle du plot et de l'assemblage sont présentées. Mots clefs-Dynamique non linéaire, équilibrage harmonique, essais vibratoires, chaos polynomial
Data in Brief, Apr 1, 2021
Procedia Engineering, 2017
In presence of friction, the frequency response function of a metallic assembly is strongly depen... more In presence of friction, the frequency response function of a metallic assembly is strongly dependent on the excitation level. The local stick-slip behavior at the friction interfaces induces energy dissipation and local stiffness softening. These phenomena are studied both experimentally and numerically on a test structure named "Harmony". Concerning the numerical part, a classical complete methodology from the finite element and friction modeling to the prediction of the nonlinear vibrational response is implemented. The well-known Harmonic Balance Method with a specific condensation process on the nonlinear frictional elements is achieved. Also, vibration experiments are performed to validate not only the finite element model of the test structure named "Harmony" at low excitation levels but also to investigate the nonlinear behavior of the system on several excitation levels. A scanning laser vibrometer is used to measure the nonlinear behavior and the local stick-slip movement near the contacts.
Journal of Sound and Vibration, Jul 1, 2019
This paper presents experiments and numerical simulations of a nonlinear rubber isolator subjecte... more This paper presents experiments and numerical simulations of a nonlinear rubber isolator subjected to both harmonic and broadband random excitations. Harmonic and broadband random excitations are performed experimentally in order to show the softening effect of the rubber isolator for high amplitudes of displacement and to show the temperature dependency of its mechanical properties. Firstly, the rubber isolator is modeled as a one degree-of-freedom system, whose stiffness and damping depend only on the amplitude of the relative displacement of the joint. The relationship between the stiffness and the damping versus the amplitude of the relative displacement of the rubber isolator is updated via experiments. Secondly, the Harmonic Balance Method (HBM) and the shooting method are presented and extended to take into account both harmonic and random excitations. A modification of the nonlinear methods is necessary in order to recover the information concerning the displacement amplitude. Moreover, for random excitations, a periodogram strategy is used to ensure a good estimate of the resulting Power Spectral Density (PSD). Finally, comparisons between experiments and simulations are undertaken. Good correlations are observed for harmonic and broadband random excitations, thus validating the modeling of the rubber isolator and the proposed nonlinear methodology.
Journal of Sound and Vibration, Oct 1, 2019
The structure Harmony-Gamma is a metallic assembly representative of an industrial structure for ... more The structure Harmony-Gamma is a metallic assembly representative of an industrial structure for which the vibratory response is influenced by the apparition of nonlinear phenomena within two specific types of joints, the first corresponding to friction joints and the second to elastomer joints. Firstly, the paper presents the experimental procedure and results obtained for this structure. Secondly, a global methodology for modeling and simulation of the nonlinear vibrational response is set up. The experiments are performed for longitudinal and transverse swept sine experiments. First of all, swept sine experiments are performed at low excitation levels on the structure in order to update a linear finiteelement model. Then, the evolution of the frequency response function is studied at increasing excitation levels in order to identify the contribution of the nonlinear effects on the global vibrational response of the system. The methodology for modeling and simulation consists of five steps. Firstly, a finite-element model of the structure is presented and updated in order to be representative of the structure when it is excited at low excitation levels. This model is then reduced using a hybrid sub-structuring technique. Thirdly, the nonlinear models of the friction and elastomer joints are added. The resulting optimization problem is solved by means of the Harmonic Balance Method (HBM) coupled with a Newton-Raphson continuation and a condensation process. Lastly, the simulation results are compared to the experimental results in order to validate the development of the finite element model for the nonlinear industrial structure Harmony-Gamma with nonlinear joints of different natures and to achieve a refined understanding of the nonlinear phenomena and their origin.
European Journal of Mechanics A-solids, Nov 1, 2022
Data in Brief, Aug 1, 2022
Data in Brief, Dec 1, 2019
Communications in Nonlinear Science and Numerical Simulation, Jul 1, 2022
This paper presents experiments and numerical simulations of a nonlinear clampedclamped beam subj... more This paper presents experiments and numerical simulations of a nonlinear clampedclamped beam subjected to Harmonic excitations and epistemic uncertainties. These uncertainties are propagated in order to calculate the dynamic response of the nonlinear structure via a coupling between the Harmonic Balance Method (HBM) and a nonintrusive Polynomial Chaos Expansion (PCE). The system studied is a clamped-clamped steel beam. First of all, increasing and decreasing swept sine experiments are performed in order to show the hardening effect in the vicinity of the primary resonance, and to extract the experimental multi-Harmonic frequency response of the structure. Secondly, the Harmonic Balance Method (HBM) is used alongside a continuation process to simulate the deterministic response of the nonlinear clamped-clamped beam. Good correlations were observed with the experiments, on the condition of updating the model for each excitation level. Finally, the effects of the epistemic uncertainties on the variability of the nonlinear response are investigated using a non-intrusive Polynomial Chaos Expansion (PCE) alongside the Harmonic Balance Method (HBM). A new methodology based on a phase criterion was developed in order to allow the PCE analysis to be performed despite the presence of bifurcations in the nonlinear response. The efficiency and robustness of the proposed methodology is demonstrated by comparison with Monte Carlo simulations. Then, the stochastic numerical results are shown to envelope the experimental responses for each excitation level without the need for model updating, validating the nonlinear stochastic methodology as a whole.
HAL (Le Centre pour la Communication Scientifique Directe), 2008
L’assemblage metallique etudie comprend des liaisons constituees de pieces en contact. La reponse... more L’assemblage metallique etudie comprend des liaisons constituees de pieces en contact. La reponse vibratoire est influencee par l’apparition de frottement dans ces liaisons. Elle est observee experimentalement et simulee numeriquement. La methode de simulation se base sur un modele element fini de l’assemblage, une reduction de modele, l’introduction d’un modele de frottement non-lineaire et enfin la resolution par la methode de balance harmonique avec continuation. Des comparaisons essaicalcul globales et locales sont presentees
Journal of Sound and Vibration, 2016
The nonlinear vibration response of an assembly with friction joints-named "Harmony"-is studied b... more The nonlinear vibration response of an assembly with friction joints-named "Harmony"-is studied both experimentally and numerically. The experimental results exhibit a softening effect and an increase of dissipation with excitation level. Modal interactions due to friction are also evidenced. The numerical methodology proposed groups together well-known structural dynamic methods, including finite elements, substructuring, Harmonic Balance and continuation methods. On the one hand, the application of this methodology proves its capacity to treat a complex system where several friction movements occur at the same time. On the other hand, the main contribution of this paper is the experimental and numerical study of evidence of modal interactions due to friction. The simulation methodology succeeds in reproducing complex form of dynamic behavior such as these modal interactions.
Mechanical Systems and Signal Processing, 2016
HAL is a multidisciplinary open access archive for the deposit and dissemination of scientific re... more HAL is a multidisciplinary open access archive for the deposit and dissemination of scientific research documents, whether they are published or not. The documents may come from teaching and research institutions in France or abroad, or from public or private research centers. L'archive ouverte pluridisciplinaire HAL, est destinée au dépôt et à la diffusion de documents scientifiques de niveau recherche, publiés ou non, émanant des établissements d'enseignement et de recherche français ou étrangers, des laboratoires publics ou privés.
Essais Industriels, 2001
La norme incendie fixant l'essai a 800 °C pendant une 1/2 h ou 1 h ne couvre pas tout le spec... more La norme incendie fixant l'essai a 800 °C pendant une 1/2 h ou 1 h ne couvre pas tout le spectre des accidents constates. Il est apparu necessaire d'affiner les connaissances theoriques et experimentales dans les conditions hors normes qui peuvent se produire lors d'un sinistre et ainsi de savoir les modeliser.
Ce document présente l'étude de la réponse vibratoire non-linéaire d'une poutre en acier encastré... more Ce document présente l'étude de la réponse vibratoire non-linéaire d'une poutre en acier encastrée à ses deux extrémités et soumise à des excitations harmoniques. Un modèle analytique non-linéaire de la poutre prenant en compte des conditions d'encastrement non-idéales est développé. La détermination de la réponse dynamique non-linéaire est alors traitée par deux approches non-linéaires : une méthode de développement multi-échelles et une technique de balance harmonique. Après un recalage du modèle physique vis-à-vis d'un nombre restreint de paramètres, les résultats théoriques sont comparés à des résultats expérimentaux.
Journal of sound and vibration, May 1, 2024
Communications in Nonlinear Science and Numerical Simulation, Jul 1, 2019
This paper presents experiments and numerical simulations of a nonlinear clampedclamped beam subj... more This paper presents experiments and numerical simulations of a nonlinear clampedclamped beam subjected to Harmonic excitations and epistemic uncertainties. These uncertainties are propagated in order to calculate the dynamic response of the nonlinear structure via a coupling between the Harmonic Balance Method (HBM) and a nonintrusive Polynomial Chaos Expansion (PCE). The system studied is a clamped-clamped steel beam. First of all, increasing and decreasing swept sine experiments are performed in order to show the hardening effect in the vicinity of the primary resonance, and to extract the experimental multi-Harmonic frequency response of the structure. Secondly, the Harmonic Balance Method (HBM) is used alongside a continuation process to simulate the deterministic response of the nonlinear clamped-clamped beam. Good correlations were observed with the experiments, on the condition of updating the model for each excitation level. Finally, the effects of the epistemic uncertainties on the variability of the nonlinear response are investigated using a non-intrusive Polynomial Chaos Expansion (PCE) alongside the Harmonic Balance Method (HBM). A new methodology based on a phase criterion was developed in order to allow the PCE analysis to be performed despite the presence of bifurcations in the nonlinear response. The efficiency and robustness of the proposed methodology is demonstrated by comparison with Monte Carlo simulations. Then, the stochastic numerical results are shown to envelope the experimental responses for each excitation level without the need for model updating, validating the nonlinear stochastic methodology as a whole.
Mechanical Systems and Signal Processing, Oct 1, 2021
The structure Harmony-Gamma is a metallic assembly representative of an industrial structure for ... more The structure Harmony-Gamma is a metallic assembly representative of an industrial structure for which the vibratory response is influenced by the apparition of nonlinear phenomena within two specific types of joints, the first corresponding to friction joints and the second to elastomer joints. The present study extends the previous work based on experiments and numerical simulations of the structure Harmony-Gamma subjected to harmonic vibrations [1]. More specifically, the nonlinear vibrational behaviour of the assembly subjected to random broadband excitations is studied. Broadband excitations are performed experimentally, in order to provide a first understanding of the nonlinear effect of both the friction and elastomer joints. Additionally, a global numerical methodology based on finite-element modelling and the use of the Harmonic Balance Method for the prediction of the nonlinear response of the Harmony-Gamma structure subjected to stochastic excitation is proposed. It is demonstrated that the use of a numerical model that has been validated against experimental tests can furthermore be used to achieve a refined understanding of the nonlinear phenomena and their origin.
Mechanical Systems and Signal Processing, Sep 1, 2018
This paper presents experiments and numerical simulations of a nonlinear clamped-clamped beam sub... more This paper presents experiments and numerical simulations of a nonlinear clamped-clamped beam subjected to Harmonic excitations and epistemic uncertainties. These uncertainties are propagated in order to calculate the dynamic response of the nonlinear structure via a coupling between the Harmonic Balance Method (HBM) and a non-intrusive Polynomial Chaos Expansion (PCE). The system studied is a clampedclamped steel beam. First of all, increasing and decreasing swept sine experiments are performed in order to show the hardening effect in the vicinity of the primary resonance, and to extract the experimental multi-Harmonic frequency response of the structure. Secondly, the Harmonic Balance Method (HBM) is used alongside a continuation process to simulate the deterministic response of the nonlinear clamped-clamped beam. Good correlations were observed with the experiments, on the condition of updating the model for each excitation level. Finally, the effects of the epistemic uncertainties on the variability of the nonlinear response are investigated using a non-intrusive Polynomial Chaos Expansion (PCE) alongside the Harmonic Balance Method (HBM). A new methodology based on a phase criterion was developed in order to allow the PCE analysis to be performed despite the presence of bifurcations in the nonlinear response. The efficiency and robustness of the proposed methodology is demonstrated by comparison with Monte Carlo simulations. Then, the stochastic numerical results are shown to envelope the experimental responses for each excitation level without the need for model updating, validating the nonlinear stochastic methodology as a whole.
HAL (Le Centre pour la Communication Scientifique Directe), May 15, 2017
-L'assemblage métallique étudié comprend neuf plots viscoélastiques en élastomère. La réponse vib... more -L'assemblage métallique étudié comprend neuf plots viscoélastiques en élastomère. La réponse vibratoire est influencée par le comportement non linéaire des plots. Un modèle élément fini de l'assemblage complet ainsi qu'un modèle de non-linéarité empirique issu d'essais unitaires sur des plots viscoélastiques seuls sont proposés. La méthode de simulation utilisée se base sur une réduction de modèle et une résolution par la méthode d'équilibrage harmonique incrémentale. Dans un second temps, la réponse dynamique non linéaire en présence d'incertitudes est proposée par l'intermédiaire du Chaos Polynomial non intrusif. Des comparaisons essais-calculs à l'échelle du plot et de l'assemblage sont présentées. Mots clefs-Dynamique non linéaire, équilibrage harmonique, essais vibratoires, chaos polynomial
Data in Brief, Apr 1, 2021
Procedia Engineering, 2017
In presence of friction, the frequency response function of a metallic assembly is strongly depen... more In presence of friction, the frequency response function of a metallic assembly is strongly dependent on the excitation level. The local stick-slip behavior at the friction interfaces induces energy dissipation and local stiffness softening. These phenomena are studied both experimentally and numerically on a test structure named "Harmony". Concerning the numerical part, a classical complete methodology from the finite element and friction modeling to the prediction of the nonlinear vibrational response is implemented. The well-known Harmonic Balance Method with a specific condensation process on the nonlinear frictional elements is achieved. Also, vibration experiments are performed to validate not only the finite element model of the test structure named "Harmony" at low excitation levels but also to investigate the nonlinear behavior of the system on several excitation levels. A scanning laser vibrometer is used to measure the nonlinear behavior and the local stick-slip movement near the contacts.
Journal of Sound and Vibration, Jul 1, 2019
This paper presents experiments and numerical simulations of a nonlinear rubber isolator subjecte... more This paper presents experiments and numerical simulations of a nonlinear rubber isolator subjected to both harmonic and broadband random excitations. Harmonic and broadband random excitations are performed experimentally in order to show the softening effect of the rubber isolator for high amplitudes of displacement and to show the temperature dependency of its mechanical properties. Firstly, the rubber isolator is modeled as a one degree-of-freedom system, whose stiffness and damping depend only on the amplitude of the relative displacement of the joint. The relationship between the stiffness and the damping versus the amplitude of the relative displacement of the rubber isolator is updated via experiments. Secondly, the Harmonic Balance Method (HBM) and the shooting method are presented and extended to take into account both harmonic and random excitations. A modification of the nonlinear methods is necessary in order to recover the information concerning the displacement amplitude. Moreover, for random excitations, a periodogram strategy is used to ensure a good estimate of the resulting Power Spectral Density (PSD). Finally, comparisons between experiments and simulations are undertaken. Good correlations are observed for harmonic and broadband random excitations, thus validating the modeling of the rubber isolator and the proposed nonlinear methodology.
Journal of Sound and Vibration, Oct 1, 2019
The structure Harmony-Gamma is a metallic assembly representative of an industrial structure for ... more The structure Harmony-Gamma is a metallic assembly representative of an industrial structure for which the vibratory response is influenced by the apparition of nonlinear phenomena within two specific types of joints, the first corresponding to friction joints and the second to elastomer joints. Firstly, the paper presents the experimental procedure and results obtained for this structure. Secondly, a global methodology for modeling and simulation of the nonlinear vibrational response is set up. The experiments are performed for longitudinal and transverse swept sine experiments. First of all, swept sine experiments are performed at low excitation levels on the structure in order to update a linear finiteelement model. Then, the evolution of the frequency response function is studied at increasing excitation levels in order to identify the contribution of the nonlinear effects on the global vibrational response of the system. The methodology for modeling and simulation consists of five steps. Firstly, a finite-element model of the structure is presented and updated in order to be representative of the structure when it is excited at low excitation levels. This model is then reduced using a hybrid sub-structuring technique. Thirdly, the nonlinear models of the friction and elastomer joints are added. The resulting optimization problem is solved by means of the Harmonic Balance Method (HBM) coupled with a Newton-Raphson continuation and a condensation process. Lastly, the simulation results are compared to the experimental results in order to validate the development of the finite element model for the nonlinear industrial structure Harmony-Gamma with nonlinear joints of different natures and to achieve a refined understanding of the nonlinear phenomena and their origin.
European Journal of Mechanics A-solids, Nov 1, 2022
Data in Brief, Aug 1, 2022
Data in Brief, Dec 1, 2019
Communications in Nonlinear Science and Numerical Simulation, Jul 1, 2022
This paper presents experiments and numerical simulations of a nonlinear clampedclamped beam subj... more This paper presents experiments and numerical simulations of a nonlinear clampedclamped beam subjected to Harmonic excitations and epistemic uncertainties. These uncertainties are propagated in order to calculate the dynamic response of the nonlinear structure via a coupling between the Harmonic Balance Method (HBM) and a nonintrusive Polynomial Chaos Expansion (PCE). The system studied is a clamped-clamped steel beam. First of all, increasing and decreasing swept sine experiments are performed in order to show the hardening effect in the vicinity of the primary resonance, and to extract the experimental multi-Harmonic frequency response of the structure. Secondly, the Harmonic Balance Method (HBM) is used alongside a continuation process to simulate the deterministic response of the nonlinear clamped-clamped beam. Good correlations were observed with the experiments, on the condition of updating the model for each excitation level. Finally, the effects of the epistemic uncertainties on the variability of the nonlinear response are investigated using a non-intrusive Polynomial Chaos Expansion (PCE) alongside the Harmonic Balance Method (HBM). A new methodology based on a phase criterion was developed in order to allow the PCE analysis to be performed despite the presence of bifurcations in the nonlinear response. The efficiency and robustness of the proposed methodology is demonstrated by comparison with Monte Carlo simulations. Then, the stochastic numerical results are shown to envelope the experimental responses for each excitation level without the need for model updating, validating the nonlinear stochastic methodology as a whole.
HAL (Le Centre pour la Communication Scientifique Directe), 2008
L’assemblage metallique etudie comprend des liaisons constituees de pieces en contact. La reponse... more L’assemblage metallique etudie comprend des liaisons constituees de pieces en contact. La reponse vibratoire est influencee par l’apparition de frottement dans ces liaisons. Elle est observee experimentalement et simulee numeriquement. La methode de simulation se base sur un modele element fini de l’assemblage, une reduction de modele, l’introduction d’un modele de frottement non-lineaire et enfin la resolution par la methode de balance harmonique avec continuation. Des comparaisons essaicalcul globales et locales sont presentees
Journal of Sound and Vibration, 2016
The nonlinear vibration response of an assembly with friction joints-named "Harmony"-is studied b... more The nonlinear vibration response of an assembly with friction joints-named "Harmony"-is studied both experimentally and numerically. The experimental results exhibit a softening effect and an increase of dissipation with excitation level. Modal interactions due to friction are also evidenced. The numerical methodology proposed groups together well-known structural dynamic methods, including finite elements, substructuring, Harmonic Balance and continuation methods. On the one hand, the application of this methodology proves its capacity to treat a complex system where several friction movements occur at the same time. On the other hand, the main contribution of this paper is the experimental and numerical study of evidence of modal interactions due to friction. The simulation methodology succeeds in reproducing complex form of dynamic behavior such as these modal interactions.
Mechanical Systems and Signal Processing, 2016
HAL is a multidisciplinary open access archive for the deposit and dissemination of scientific re... more HAL is a multidisciplinary open access archive for the deposit and dissemination of scientific research documents, whether they are published or not. The documents may come from teaching and research institutions in France or abroad, or from public or private research centers. L'archive ouverte pluridisciplinaire HAL, est destinée au dépôt et à la diffusion de documents scientifiques de niveau recherche, publiés ou non, émanant des établissements d'enseignement et de recherche français ou étrangers, des laboratoires publics ou privés.
Essais Industriels, 2001
La norme incendie fixant l'essai a 800 °C pendant une 1/2 h ou 1 h ne couvre pas tout le spec... more La norme incendie fixant l'essai a 800 °C pendant une 1/2 h ou 1 h ne couvre pas tout le spectre des accidents constates. Il est apparu necessaire d'affiner les connaissances theoriques et experimentales dans les conditions hors normes qui peuvent se produire lors d'un sinistre et ainsi de savoir les modeliser.
Ce document présente l'étude de la réponse vibratoire non-linéaire d'une poutre en acier encastré... more Ce document présente l'étude de la réponse vibratoire non-linéaire d'une poutre en acier encastrée à ses deux extrémités et soumise à des excitations harmoniques. Un modèle analytique non-linéaire de la poutre prenant en compte des conditions d'encastrement non-idéales est développé. La détermination de la réponse dynamique non-linéaire est alors traitée par deux approches non-linéaires : une méthode de développement multi-échelles et une technique de balance harmonique. Après un recalage du modèle physique vis-à-vis d'un nombre restreint de paramètres, les résultats théoriques sont comparés à des résultats expérimentaux.