Hi,
The data obtained from tensile test is not reliable after the point of maximum load as neck initiates and triaxial state of stress develops.There is lot of literature in this regard, Can anyone suggest a good method to obtain the exact load disp curve after necking.
regards
ROHITH
See this paper
Please see the paper published at Mechanics of Materials. Volume 40, Issue 7, July 2008, Pages 586-593
A new method for acquiring true stress–strain curves over a large range of strains using a tensile test and finite element method
Ying Li Department of Engineering Mechanics Tsinghua University Beijing, 100084, P. R. CHINA
Rohith, Look up the
Rohith,
Look up the Bridgeman solution, that is the most basic relationship linking the axial stress, pressure in the neck, and radius of curvature of the neck. It appears in most textbooks on tensile testing/mechanics of solids. There have been several adjustments to the expression, but that is a good place to start. One note is that you do need to measure diametral contraction during the tensile test in order to get the post-necking curve.
Best,
-Ken
Hi ken , Thanks, I am
Hi ken ,
Thanks, I am aware of bridgeman solution. One has to put a lot of effort in measuring the dimensions during the deformation process . Bridgeman solution may be convinient for round specimens but its not convinient for sheet specimens. Thats is why I am looking for an FEM solution to use the data from the test only upto necking and simulate and later part using fem by minimizing the error between load disp curve of theoritical and fem solution.
Rohith