Introduction to the Program: tested on Matlab Version R2014a & R2018a

Local-Peaks Search Method (LPS Method) - Dispersion equation solving method. for the following Models:

• Free or Fluid-loaded, Single- or Double-Layer, Elastic or Viscoelastic Plates;
• Free or Fluid-loaded, Single- or Double-Layer, Elastic or Viscoelastic Cylindrical Shells.

• Orginally programmed at Harbin Engineering University(HEU), hrbin, PRC, 2009;
• Revised at Insititute of Acoustics, Chinese Academy of Sciences(IACAS),QingDao, PRC, 2011-2016
• Modified at Hubei University of Automotive Technology(HUAT), Shiyan, PRC, 2018

Jiayuan Gong. Study on Leaky Lamb Waves Propagating in Elastic Plates and Cylindrical Shells Coated with a Viscoelastic Damping Material in Water(水中覆阻尼层弹性板及柱壳中的漏Lamb波研究). Graduation Thesis of Master's Degree, Harbin Engineering University, 2010. (in Chinese)

The Code for cylindrical shells has some bugs. Anyone who optimizes the program, please share wtih the developer, thanks a lot.

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       Fluid 1 [Fl, Va]: row1,c1
  

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   Material 2 [So]: rowvm, Evm0, ytavm, sigmavm      
  

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  Material 1 [So]: rowem, Eem0, ytaem, sigmaem
  

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      Fluid 2 [Fl, Va]: row2, c2
  

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1. Problem Selection

• Model Selection:
  (a) PlanarPlate; (b) CylindricalShell
• BCs:
  Va-free or vacuum; So-solid; Fl-fluid
• Mode:
  (a) PlanarPlate: S-symmetrical; A-asymmetrical
  (b) CylindricalShell: L-longitudinal; T-tortional; F-flexural
• ncs:
  flexural modal order of cylindrical shells

2. Model Size

• Plates:
  dem-thickness of material 1; dvm-thickness of material 2
• Cylindrical Shells:
  a-inner radius; b-middle radius; c-outer radius

3. Material Parameters

• Fluid 1:
  row1, c1 - acoustic parameters of fluid 1
• Material 1: elastic:
  rowem, Eem0, ytaem, sigmaem ---- parameters of material 1, elastic default
• Material 2: viscoelastic:
  rowvm, Evm0, ytavm, sigmavm ---- parameters of material 2, viscoelastic default
• Fluid 2:
  row2, c2 - acoustic parameters of fluid 2

4. Computation Parameters

• Frequency Range:
  f = [fa:df:fb]
• Phase Velocity:
  cp = [cpa:dcp:cpb]
• Attenuation Coefficient:
  ki = [kia:dki:kib]
• Control Parameters:
  (a) kur - used to determine a local-peak
  (b) err - roots' precision
• Notes: wavenumber k = w/cp+i*ki

5. Inialize & Save

• Initialize:
  initialize the parameters using 'Initializer.mat' file saved last time
• Save:
  save the parameters set currently to 'Initializer.mat' file

6. Run run the program

When the program is running, some dialog boxes will pop-up, which is intended to check the roots obtained through observation by yourself.

• Choice: to check roots manually?
  please click 'Yes' or 'No' to determine whether check roots yourself.
• Check roots: Begin to check roots?
  'Yes'-check; 'No'-not check; 'Never'-not check any more
• Is this a root?
  through observation to determine a root or not, press "ctrl+C" to changer the current figure
  'Yes'-is a root; 'No'-not a root; 'Cancel? not sure