Waqas Khan
2008-05-24, 22:46
Hi,
Mr. Bergstrom, you always talk about having a relaxation curve to define a viscoelastic material in any FEM code. If I am correct the relaxation curve is obtained by experiment in which u put a constant strain and then measure the stress with time. Since the stress decreases, therefore the Young modulus E(t) must decrease with time upto a certain limit.
However, is it the same if we use a creep test b/c in a creep test, u keep the stress (load) constant and then measure the increase in strain. In this case also, the Young Modulus must decrease with time.
Is there a difference b/w the two curves obtained and if so, why is a difference there?
I know that these are not questions of your level and i am really sorry but I am a student of bachelor's.
Thank u.
Mr. Bergstrom, you always talk about having a relaxation curve to define a viscoelastic material in any FEM code. If I am correct the relaxation curve is obtained by experiment in which u put a constant strain and then measure the stress with time. Since the stress decreases, therefore the Young modulus E(t) must decrease with time upto a certain limit.
However, is it the same if we use a creep test b/c in a creep test, u keep the stress (load) constant and then measure the increase in strain. In this case also, the Young Modulus must decrease with time.
Is there a difference b/w the two curves obtained and if so, why is a difference there?
I know that these are not questions of your level and i am really sorry but I am a student of bachelor's.
Thank u.