jdps
Aerospace
- Mar 26, 2020
- 8
My understanding of Neuber's Correction/Method is that it allows for the estimation of nonlinear stresses from the corresponding linear elastic stresses by equating strain energy. I've recently been doing a little more research into the topic and would like some help understanding.
From reading Neuber's paper, Neuber's rule states that the theoretical stress concentration factor is equal to the geometric mean of the stress and strain concentration factors. Ive seen this rule applied in several papers and even an example in Roark to estimate the nonlinear stress/strain state at notch locations from the nominal stress/strain state. Neubers rule seems somewhat intuitive as I can see how as the stress concentration factor decreases, the strain concentration factor should increase. I also understand Neuber rule's application as used in Roark to calculate the stress/strain state at a notch fillet using the nominal stress/strain at the section as it seems equivalent to applying a stress concentration factor.
My confusion comes when trying to understand how Neuber's Correction method developed from Neuber's rule. My understanding of the Neuber Correction method is that, under certain situations, you can equate the strain energy of the fictitious stress state found from linear elastic analysis to another state along the elastic-plastic curve. This seems to hinge solely on strain energy and not on a theoretical stress concentration factor or have any relation to Neuber's rule. What am I misunderstanding?
From reading Neuber's paper, Neuber's rule states that the theoretical stress concentration factor is equal to the geometric mean of the stress and strain concentration factors. Ive seen this rule applied in several papers and even an example in Roark to estimate the nonlinear stress/strain state at notch locations from the nominal stress/strain state. Neubers rule seems somewhat intuitive as I can see how as the stress concentration factor decreases, the strain concentration factor should increase. I also understand Neuber rule's application as used in Roark to calculate the stress/strain state at a notch fillet using the nominal stress/strain at the section as it seems equivalent to applying a stress concentration factor.
My confusion comes when trying to understand how Neuber's Correction method developed from Neuber's rule. My understanding of the Neuber Correction method is that, under certain situations, you can equate the strain energy of the fictitious stress state found from linear elastic analysis to another state along the elastic-plastic curve. This seems to hinge solely on strain energy and not on a theoretical stress concentration factor or have any relation to Neuber's rule. What am I misunderstanding?