Non-linear flexural rigidity (EI)
Non-linear flexural rigidity (EI)
(OP)
Hi all,
I am trying to find the fexlural rigidity of a bending beam under a load increasing step-by-step till the beam fails. Assuming material is non-linearity, can I use this formula:
Flexural rigidity (EI) = Bending moment (M)/Curvature
to calculate EI for non-linear material?
Could anyone help me in this point.
Thanking you in advance.
regards,
Jaguar9
I am trying to find the fexlural rigidity of a bending beam under a load increasing step-by-step till the beam fails. Assuming material is non-linearity, can I use this formula:
Flexural rigidity (EI) = Bending moment (M)/Curvature
to calculate EI for non-linear material?
Could anyone help me in this point.
Thanking you in advance.
regards,
Jaguar9





RE: Non-linear flexural rigidity (EI)
(1) Plane sections remain plane;
(2) The longitudinal stress at any point on the cross section is proportional to the strain at that point.
For a non-linear material, condition (2) is violated by definition.
HTH
RE: Non-linear flexural rigidity (EI)
Are you doing this experimentally?
RE: Non-linear flexural rigidity (EI)
Can EI be set up for linear inelastic case(?): assuming that moment and curvature can be found from a given stress-strain curve with a linear degradation of tensile stress?
Heitor: I am not doing experiment for this
regards,
Jaguar9
RE: Non-linear flexural rigidity (EI)
University and DOE lab research has been trying to calibrate models in nonlinear code such as DYNA (tm) to impact and crash test results for years. I can give you a contact. If you are interested just supply your e-mail address.
From doing some simple experiments I can attest to the observations that published post-yield material behavior varies widely. Piecewise look up is probably more accurate than linear degredation. Cyclic work hardening history and section geometry are also big players for the gross beam behavior.
RE: Non-linear flexural rigidity (EI)
Thank you very much. I would be very grateful if you would contact me through this email
jaguar9_do@yahoo.com
Regards,
Jaguar9