Deformation of parabolic shell surface under explosion shock waves is a complex dynamic problem. Because of reflection and interference of blast wave, it＇s hard to analytically delineate the dynamic responds of radar...Deformation of parabolic shell surface under explosion shock waves is a complex dynamic problem. Because of reflection and interference of blast wave, it＇s hard to analytically delineate the dynamic responds of radar parabolic shell surface on blast wave. To gain the characteristics of thin shell deformation under impulsive loading of blast wave, numerical simulation methods for blast load on the shell structure was studied and analyzed. Euler-Lagrange numerical simulation was implemen- ted by AUTODYN code to simulate the problem. Through analysis on deflection feature of radial po- sition under different explosive mass and detonation height, an equation was founded by fitting the deflection results from numerical simulation results of shockwave loading. Experiments were ar- ranged to confirm the validity of the formula. The results gained by simulation are consistent with experiments, and the formula can be used to delineate the deflection of aluminum alloy parabolic shell under blast loading.展开更多
We investigate strong exciton-plasmon coupling and plasmon-mediated hybridization between the Frenkel(F)and Wannier–Mott(WM)excitons of an organic-inorganic hybrid system consisting of a silver ring separated from a ...We investigate strong exciton-plasmon coupling and plasmon-mediated hybridization between the Frenkel(F)and Wannier–Mott(WM)excitons of an organic-inorganic hybrid system consisting of a silver ring separated from a monolayer WS2 by J-aggregates.The extinction spectra of the hybrid system calculated by employing the coupled oscillator model are consistent with the results simulated by the finite-difference time-domain method.The calculation results show that strong couplings among F excitons,WM excitons,and localized surface plasmon resonances(LSPRs)lead to the appearance of three plexciton branches in the extinction spectra.The weighting efficiencies of the F exciton,WM exciton and LSPR modes in three plexciton branches are used to analyze the exciton-polaritons in the system.Furthermore,the strong coupling between two different excitons and LSPRs is manipulated by tuning F or WM exciton resonances.展开更多
It＇ s a problem to be solved how to de-noise the signal of blast shock wave overpressure. In the conventional methods, the high frequency of the signal is cut directly by some mathematics algorithms, such as Fourier ...It＇ s a problem to be solved how to de-noise the signal of blast shock wave overpressure. In the conventional methods, the high frequency of the signal is cut directly by some mathematics algorithms, such as Fourier Transform, but some of the useful signal will be cut together. We adopt a new method for the signal de-noising of shock wave overpressure by wavelet analysis, There are four steps in this method. Firstly, the original signal is de-compoed. Then the time-frequency features of the signal and noise are analyzed. Thirdly, the noise is separated from the signal by only cutting its frequency while the useful signal frequency is reserved as much as possible. Lastly, the useful signal with least loss of information is recovered by reconstruction process. To verify this method, a blast shock wave signal is de-noised with FFF to make a comparison. The results show that the signal de-noised by wavelet analysis approximates the ideal signal well.展开更多
A comprehensive model that included mechanical dynamics of the shock absorber coupled with its thermal properties was proposed innovatively.Moreover a thermal-mechanical coupled model which reflected the closed-loop p...A comprehensive model that included mechanical dynamics of the shock absorber coupled with its thermal properties was proposed innovatively.Moreover a thermal-mechanical coupled model which reflected the closed-loop positive feedback system was established by using MATLAB/SIMULINK,and some curves of shock absorber temperature rising characteristic were obtained by simulation ＆computation under several operating modes and different parameters conditions.Research results show that：shock absorber design parameters,external excitations,and thermo-physical properties parameter,such as oil density have effect on the shock absorber temperature rising characteristic.However other thermo-physical properties parameters,such as oil specific heat,cylinder density,cylinder specific heat,and cylinder thermal conductivity,have no effect on it.The results may be used for studying reliability design of the shock absorber.展开更多
基金Supported by the National Defense Basic Science Foundation(B1020060357)
文摘Deformation of parabolic shell surface under explosion shock waves is a complex dynamic problem. Because of reflection and interference of blast wave, it＇s hard to analytically delineate the dynamic responds of radar parabolic shell surface on blast wave. To gain the characteristics of thin shell deformation under impulsive loading of blast wave, numerical simulation methods for blast load on the shell structure was studied and analyzed. Euler-Lagrange numerical simulation was implemen- ted by AUTODYN code to simulate the problem. Through analysis on deflection feature of radial po- sition under different explosive mass and detonation height, an equation was founded by fitting the deflection results from numerical simulation results of shockwave loading. Experiments were ar- ranged to confirm the validity of the formula. The results gained by simulation are consistent with experiments, and the formula can be used to delineate the deflection of aluminum alloy parabolic shell under blast loading.
基金Supported by the National Key Research and Development Program of China under Grant No 2016YFA0301300the National Natural Science Foundation of China under Grant Nos 11574035 and 11374041the State Key Laboratory of Information Photonics and Optical Communications
文摘We investigate strong exciton-plasmon coupling and plasmon-mediated hybridization between the Frenkel(F)and Wannier–Mott(WM)excitons of an organic-inorganic hybrid system consisting of a silver ring separated from a monolayer WS2 by J-aggregates.The extinction spectra of the hybrid system calculated by employing the coupled oscillator model are consistent with the results simulated by the finite-difference time-domain method.The calculation results show that strong couplings among F excitons,WM excitons,and localized surface plasmon resonances(LSPRs)lead to the appearance of three plexciton branches in the extinction spectra.The weighting efficiencies of the F exciton,WM exciton and LSPR modes in three plexciton branches are used to analyze the exciton-polaritons in the system.Furthermore,the strong coupling between two different excitons and LSPRs is manipulated by tuning F or WM exciton resonances.
文摘It＇ s a problem to be solved how to de-noise the signal of blast shock wave overpressure. In the conventional methods, the high frequency of the signal is cut directly by some mathematics algorithms, such as Fourier Transform, but some of the useful signal will be cut together. We adopt a new method for the signal de-noising of shock wave overpressure by wavelet analysis, There are four steps in this method. Firstly, the original signal is de-compoed. Then the time-frequency features of the signal and noise are analyzed. Thirdly, the noise is separated from the signal by only cutting its frequency while the useful signal frequency is reserved as much as possible. Lastly, the useful signal with least loss of information is recovered by reconstruction process. To verify this method, a blast shock wave signal is de-noised with FFF to make a comparison. The results show that the signal de-noised by wavelet analysis approximates the ideal signal well.
基金Supported by Central Universities Fundamental Research Projects Foundation(11QG22)State Key Laboratory of Automobile Noise Vibration and Safety Projects Foundation(NVHSKL-201105)
文摘A comprehensive model that included mechanical dynamics of the shock absorber coupled with its thermal properties was proposed innovatively.Moreover a thermal-mechanical coupled model which reflected the closed-loop positive feedback system was established by using MATLAB/SIMULINK,and some curves of shock absorber temperature rising characteristic were obtained by simulation ＆computation under several operating modes and different parameters conditions.Research results show that：shock absorber design parameters,external excitations,and thermo-physical properties parameter,such as oil density have effect on the shock absorber temperature rising characteristic.However other thermo-physical properties parameters,such as oil specific heat,cylinder density,cylinder specific heat,and cylinder thermal conductivity,have no effect on it.The results may be used for studying reliability design of the shock absorber.
