Harmonic Analysis: Alloy/Sandwich Panels Theories & Methods

[kashoo]

How can we perform Hramonic Analysis on Sandwich Panels having orthotropic Properties...What are limitation of this analysis...can i have a detailed document related to theortical ,Analytical and Experimental Methods of Perfroming Harmonic (Dynamic Analysis) on Alloy or Sandwich Panels.

 

[PerennialII]

Your question is a pretty tough one as apparent from the numerous replies .. ... hope this still helps.

The most accurate method of vibration / dynamic analysis of a general orthotropic composite shell like structure you're considering would be to do a simple finite element model of the box - like structure (remember you describing in other thread) using composite shell elements. This way the material could be either described using either as being generally orthotropic, or by inputting the composite ply properties in each layer (the alloy case naturally isn't all that difficult).

On using either analytic or semi-analytic methods, the methods applied are the same as typically in different forms of dynamic analysis (with non-composite materials), the usual question arising is whether the structure you're working on can be reduced to an element which can be assessed using analytical means (to a well defined shell, plate, beam etc. structure, and how do the structural specifics couple with the material property distribution in this particular case). If such "reduction" can be attained, the different forms of analysis you've mentioned (other thread again) you need to assess are then easier to complete. If that is not the case, as a first approximation it can be feasible to use "semi-analytical" means, for example classical solutions of non-composite structure which have been corrected for composite structures using experimental and numerical analysis results etc.

If this is still relevant we can try to iterate this towards a more detailed solution. First off, a detailed (dimensioned) scheme/description of the structure along with the specification of different materials could be used more accurately figure out what sort of method would best suit your case (i.e. whether a non-numerical approach will bite) and whether a sort of a "semi-analytical" approach as described above were feasible (such would give the most accurate results with the least amount of work).

 

[kashoo]

Very Very Difficult Reply...I think i would rather re check material library of FEM ..to understand ur reply...:)...Anyway thanks for ur reply...(atlast i got one reply regarding this topic) ...hope to listen u again

 

[PerennialII]

... and I thought for once I was being clear enough ... & LOL. Anyways, composite problems do have their complications, but if you want to dig in deeper we can do so starting from the geometry and materials of the problem. Of course if you have access to FEM tools that is one pretty sure way of procuring a solution.