Not sure it works under Max 5, but the Mlys + modalys~ combination from Ircam (neither free nor available for Windows) can produce this kind of sounds pretty easily (the physical modelling technique used is named modal synthesis). And these sounds are quite convincing.

Interesting stuff here – http://madwiki.beds.ac.uk/madwiki/index.php/User:Dave

Also, check out the physical model stuff available in language-objects like csound~ and rtcmix~. I think (I know in the case of rtcmix~) that these are based on the waveguide filter models in the Synthesis Tookit

https://ccrma.stanford.edu/software/stk/

If you’re interested in the theoretical underpinnings, definitely scan Julius Smith’s page:

https://ccrma.stanford.edu/~jos/wg.html

and Perry Cook’s book is also a terrific resource:

http://www.cs.princeton.edu/~prc/AKPetersBook.htm

brad
http://music.columbia.edu/~brad