feadyna,
you wrote:
'I am working on birdstrike analysis on aircraft structures, using Gelatin bird. Could any one describe the method of ALE apporach to carry out the birdstrike analysis using ls-dyna.'
ALE Approach:
I am also not familiar with this terminology. I am familiar with the use of 'Eulerian' and 'Lagrangian' computer techniques for conducting birdstrike analyses. My experience lies with DYTRAN(MSC software). The exercises of performing these analyses have been extremely interesting, however the value added to the development of typical aircraft structure (leading edges, transparencies, radomes, etc)is questionable and depends upon the nature and scope of your project.
Our typical design process involves the use of proprietary software which is based in part on the RAE paper mentioned by Graham and which is supplemented by internal 'curved and flat panel' test data. The energy dissipation curves extracted from this method are applied to a non-linear finite element model typically is used for internal load development.
We have certified structure by analysis alone(supported by historical data and by new product testing alone (last full-scale test conducted in Aug of 2001). While several DYTRAN models have been developed internally: As yet we have not made use of this technique for purpose of certification.
The RAE referenced above is:
"The design of leading-edge and intake wall structure to resist impact." Royal Aircraft Establishment, Technical Report 72056, Farnborough, Hants, March 3, 1972.
A good reference for your question about the gelatin bird would be:
"Validation of a bird susbstitute for development and qualification of aircraft transparencies.", Chalita, A., Flight Dynamics Laboratory, Write-Patterson Air Force Base, Ohio, AFFDL-TR-77-60, Oct. 1980.