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Nonlinear modal interactions are frequently encountered in the dynamic responses of aerospace structures due to the activation of nonlinearities when submitted to large amplitudes of excitation. These peculiar nonlinear interactions create internal resonances, leading to an increase in the response amplitude not predicted by the linear theory. While modal interactions have been studied on numerical models and reported on real-life structures, no algorithm for their automatic detection has been proposed so far. In this context, the present work aims at developing an algorithm for the automatic detection of modal interactions, based on experimental time series recorded during industrial test campaigns. The proposed algorithm focuses on the analysis of structural responses to sinesweep excitations, which are commonly used in the industry.

The detection algorithm is based, on the one hand, on the study of the frequency content of the responses with an adaptive filter; and, on the other hand, on the assessment of the correlation between the phases and deflection shapes of higher harmonics and linear modes. The linear modal shapes are approximated by their deflection shapes at resonance during low-energy testing.

The algorithm is first discussed and validated on simulated data, using a nonlinear mass-spring system and the finite element model of a spacecraft with strong nonlinearities and high non-proportional damping. The performance of the algorithm is then demonstrated using experimental data from the spacecraft shaker test campaign.

This automatic method is fast and robust to detect the presence of modal interactions during spacecraft shaker test or aircraft ground vibration test. Therefore, it paves the way for broadening the scope of modal interaction study to industrial applications, and can be used in the design stage of mechanical structures to avoid unexpected failures during their operational lifespan.

Nonlinear vibrations --- Modal interactions --- Detection algorithm --- Nonlinear normal modes --- Experimental modal analysis --- Shaker testing --- Ingénierie, informatique & technologie > Ingénierie aérospatiale

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This is a collection of 18 papers, two of which are reviews and seven are invited feature papers, that together form the Photonics Special Issue “Semiconductor Laser Dynamics: Fundamentals and Applications”, published in 2020. This collection is edited by Daan Lenstra, an internationally recognized specialist in the field for 40 years.

History of engineering & technology --- injection locking --- optical filter --- semiconductor laser --- optical comb --- semiconductor lasers --- nonlinear dynamics --- optical injection --- chaos synchronization --- intra-cavity propagation delay --- secure optical communication --- quantum dot lasers --- excited-state --- chaos --- chaotic communication --- communication system security --- coupled lasers --- stability --- normal modes --- coupled modes --- optical injection locking --- microwave carrier generation --- hybrid photonic integration --- locking range --- photonic integrated circuit --- microwave generation --- laser dynamics --- optoelectronics oscillator --- photonic integrated circuits --- mutual coupling --- semiconductor ring laser --- optical feedback --- laser stability --- parity–time symmetry --- intensity dynamics --- feedback --- delay --- reservoir computing --- neuromorphic computing --- two delay-coupled lasers --- weak coupling limit --- optically injected laser --- InP semiconductor optical amplifier --- hybrid integration --- narrow intrinsic linewidth --- dual-wavelength laser --- laser frequency comb --- integrated photonic circuits --- low-loss Si3N4 waveguides --- external-cavity diode laser --- interference filter --- laser diode --- laser stabilization --- space optical clock --- high-speed VCSELs --- multi-mode VCSELs --- intrinsic laser dynamics --- equivalent circuit modeling --- intrinsic modulation response --- bifurcations --- laser chaos --- chaotic laser diode --- dynamics and stability --- laser coupling --- integrated lasers

Choose an application

• Reference Manager
• EndNote
• RefWorks (Direct export to RefWorks)

This is a collection of 18 papers, two of which are reviews and seven are invited feature papers, that together form the Photonics Special Issue “Semiconductor Laser Dynamics: Fundamentals and Applications”, published in 2020. This collection is edited by Daan Lenstra, an internationally recognized specialist in the field for 40 years.

History of engineering & technology --- injection locking --- optical filter --- semiconductor laser --- optical comb --- semiconductor lasers --- nonlinear dynamics --- optical injection --- chaos synchronization --- intra-cavity propagation delay --- secure optical communication --- quantum dot lasers --- excited-state --- chaos --- chaotic communication --- communication system security --- coupled lasers --- stability --- normal modes --- coupled modes --- optical injection locking --- microwave carrier generation --- hybrid photonic integration --- locking range --- photonic integrated circuit --- microwave generation --- laser dynamics --- optoelectronics oscillator --- photonic integrated circuits --- mutual coupling --- semiconductor ring laser --- optical feedback --- laser stability --- parity–time symmetry --- intensity dynamics --- feedback --- delay --- reservoir computing --- neuromorphic computing --- two delay-coupled lasers --- weak coupling limit --- optically injected laser --- InP semiconductor optical amplifier --- hybrid integration --- narrow intrinsic linewidth --- dual-wavelength laser --- laser frequency comb --- integrated photonic circuits --- low-loss Si3N4 waveguides --- external-cavity diode laser --- interference filter --- laser diode --- laser stabilization --- space optical clock --- high-speed VCSELs --- multi-mode VCSELs --- intrinsic laser dynamics --- equivalent circuit modeling --- intrinsic modulation response --- bifurcations --- laser chaos --- chaotic laser diode --- dynamics and stability --- laser coupling --- integrated lasers --- injection locking --- optical filter --- semiconductor laser --- optical comb --- semiconductor lasers --- nonlinear dynamics --- optical injection --- chaos synchronization --- intra-cavity propagation delay --- secure optical communication --- quantum dot lasers --- excited-state --- chaos --- chaotic communication --- communication system security --- coupled lasers --- stability --- normal modes --- coupled modes --- optical injection locking --- microwave carrier generation --- hybrid photonic integration --- locking range --- photonic integrated circuit --- microwave generation --- laser dynamics --- optoelectronics oscillator --- photonic integrated circuits --- mutual coupling --- semiconductor ring laser --- optical feedback --- laser stability --- parity–time symmetry --- intensity dynamics --- feedback --- delay --- reservoir computing --- neuromorphic computing --- two delay-coupled lasers --- weak coupling limit --- optically injected laser --- InP semiconductor optical amplifier --- hybrid integration --- narrow intrinsic linewidth --- dual-wavelength laser --- laser frequency comb --- integrated photonic circuits --- low-loss Si3N4 waveguides --- external-cavity diode laser --- interference filter --- laser diode --- laser stabilization --- space optical clock --- high-speed VCSELs --- multi-mode VCSELs --- intrinsic laser dynamics --- equivalent circuit modeling --- intrinsic modulation response --- bifurcations --- laser chaos --- chaotic laser diode --- dynamics and stability --- laser coupling --- integrated lasers