Reverse Classical Laminate Theory
Reverse Classical Laminate Theory
(OP)
Hi, has anyone tried performing classical laminate theory in reverse, i.e. getting lamina stiffness and strength values from experimental laminate data? I have been attempting to do so but I can’t seem to get my formulation to work correctly. I’m 99% sure it is correct because I can go from Q Matrix ---> A Matrix, but not the reverse calculation.
Surprisingly there doesn’t appear to be any commercial software that calculates this, and I have only found two academic papers which mention the reverse process. I’ve attached a PDF showing my workings as that will be a lot clearer than writing it out here.
Thanks for any help
Surprisingly there doesn’t appear to be any commercial software that calculates this, and I have only found two academic papers which mention the reverse process. I’ve attached a PDF showing my workings as that will be a lot clearer than writing it out here.
Thanks for any help





RE: Reverse Classical Laminate Theory
RE: Reverse Classical Laminate Theory
A11 = [2*Q11 + 2*Q22] * t
A22 = [2*Q11 + 2*Q22] * t
(Note that Q11 and Q22 are of course reversed for 0 and 90 plies but as they are the same value the summation is still the same result)
This means that it is impossible to find a unique solution of Q11 and Q22. The only way you can do this is if you eliminate one of the unknowns and choose a value for it – so I got rid othe Q22 equation as I can calculate E2 from micromechanics. It’s quite annoying and feels wrong to have to use a theoretical calculation to derive experimental results. I am not a mathematician so I can’t explain why these equations won’t reverse to a unique solution.