A new procedure is proposed to ease the analyses of the free vibration of an elastically connected identical plates system with respect to Kirchhoff plate theory.A structure of n parallel,elastically connected rectang...A new procedure is proposed to ease the analyses of the free vibration of an elastically connected identical plates system with respect to Kirchhoff plate theory.A structure of n parallel,elastically connected rectangular plates is of concern,whereby the motion is explained by a set of n coupled partial differential equations.The method involves a new change in variables to uncouple equations and form an equal system of n decoupled plates,while each is assumed to be elastically connected to the ground.The differential quadrature method is adopted to solve the decoupled equations.To unravel the original system,the inverse transform is applied.Decoupling the equations enables one to solve them based on the solution methods available for a single plate system.This also diminishes the computational costs of such problems.By considering different boundary conditions,a case study is run to present the method and to validate the results with its counterparts,for which excellent agreement is observed.Assessing the influence of dimensionless thickness,aspect ratio,and stiffness coefficients on the frequencies reveals the different effects of them at the low order of dimensionless natural frequencies in comparison with high orders and for different boundary conditions.展开更多
Ultrafast lasers with high repetition rate,high energy,and ultrashort pulse duration have enabled numerous applications in science and technology.One efficient route to generate such pulses is postcompression of high-...Ultrafast lasers with high repetition rate,high energy,and ultrashort pulse duration have enabled numerous applications in science and technology.One efficient route to generate such pulses is postcompression of high-power Yb-doped lasers.Here,we report on the generation of 24.5 fs pulses with an output energy of 1.6μJ and a repetition rate of 500 kHz.The pulses are obtained by using a hybrid cascaded nonlinear compression of the pulses delivered by a Yb-based fiber chirped pulse amplification(CPA)system.In the first stage,the initial 390 fs laser pulses are compressed to 100.7 fs based on spectral broadening in three fused silica plates.In the second stage,the pulses have been shortened to sub-30 fs by means of nonlinear compression in a hollow-core fiber.Overall,we could achieve∼16 times temporal shortening with the proposed approach.The results show that our system can effectively generate few-cycle pulses at a relatively high repetition rate and high energy,which can benefit future possible applications.展开更多
基金Iran National Science Foundation(INSF)under Grant No.97021731。
文摘A new procedure is proposed to ease the analyses of the free vibration of an elastically connected identical plates system with respect to Kirchhoff plate theory.A structure of n parallel,elastically connected rectangular plates is of concern,whereby the motion is explained by a set of n coupled partial differential equations.The method involves a new change in variables to uncouple equations and form an equal system of n decoupled plates,while each is assumed to be elastically connected to the ground.The differential quadrature method is adopted to solve the decoupled equations.To unravel the original system,the inverse transform is applied.Decoupling the equations enables one to solve them based on the solution methods available for a single plate system.This also diminishes the computational costs of such problems.By considering different boundary conditions,a case study is run to present the method and to validate the results with its counterparts,for which excellent agreement is observed.Assessing the influence of dimensionless thickness,aspect ratio,and stiffness coefficients on the frequencies reveals the different effects of them at the low order of dimensionless natural frequencies in comparison with high orders and for different boundary conditions.
基金supported by the National Natural Science Foundation of China(NSFC)(Nos.62105237,61827821,and 61975144).
文摘Ultrafast lasers with high repetition rate,high energy,and ultrashort pulse duration have enabled numerous applications in science and technology.One efficient route to generate such pulses is postcompression of high-power Yb-doped lasers.Here,we report on the generation of 24.5 fs pulses with an output energy of 1.6μJ and a repetition rate of 500 kHz.The pulses are obtained by using a hybrid cascaded nonlinear compression of the pulses delivered by a Yb-based fiber chirped pulse amplification(CPA)system.In the first stage,the initial 390 fs laser pulses are compressed to 100.7 fs based on spectral broadening in three fused silica plates.In the second stage,the pulses have been shortened to sub-30 fs by means of nonlinear compression in a hollow-core fiber.Overall,we could achieve∼16 times temporal shortening with the proposed approach.The results show that our system can effectively generate few-cycle pulses at a relatively high repetition rate and high energy,which can benefit future possible applications.
