Carbon fiber reinforced plastic (CFRP) possesses numerous advantages, such as a light weight and high strength; however, its complex damage mechanisms make the evaluation of fatigue damage particularly challenging. Therefore, this study proposed and demonstrated an entropy-based damage evaluation model for CFRP that leverages the entropy derived from heat capacity measurements and does not require knowledge of the loading history. This entropy-based fatigue degradation model, though accurate, is computationally intensive and impractical for high-cycle analysis.
View Article and Find Full Text PDFWe experimentally demonstrate random bit generation using multi-bit samples of bandwidth-enhanced chaos in semiconductor lasers. Chaotic fluctuation of laser output is generated in a semiconductor laser with optical feedback and the chaotic output is injected into a second semiconductor laser to obtain a chaotic intensity signal with bandwidth enhanced up to 16 GHz. The chaotic signal is converted to an 8-bit digital signal by sampling with a digital oscilloscope at 12.
View Article and Find Full Text PDFWe investigate the dynamics of two semiconductor lasers with separate optical feedback when they are driven by a common signal injected from a chaotic laser under the condition of non-identical drive and response. We experimentally and numerically show conditions under which the outputs of the two lasers can be highly correlated with each other even though the correlation with the drive signal is low. In particular, the effects of the phase of the feedback light on the correlation characteristics are described.
View Article and Find Full Text PDFPhys Rev E Stat Nonlin Soft Matter Phys
February 2009
We experimentally and numerically observe synchronization of chaos in two mutually coupled vertical-cavity surface-emitting lasers (VCSELs) with time delay. We observe in-phase and antiphase synchronization of polarization-resolved chaotic temporal wave forms under the condition of wavelength matching. We investigate leader-laggard relationship between two chaotic wave forms of mutually coupled VCSELs and find that the laser with longer wavelength becomes the leader.
View Article and Find Full Text PDFPhys Rev E Stat Nonlin Soft Matter Phys
September 2008
Local conditional Lyapunov exponents are introduced and plotted in dynamical phase space to visualize the local susceptibility of the Lorenz system driven by chaos and noise signals when the system produces consistent response outputs. The dependence of the distribution of the local conditional Lyapunov exponent on changes in the drive signal is investigated. We consider the existence of multiple basins of consistent response for the same drive signal and the dependence of the basins on the drive signal.
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