“VonMisesSR” criterion

X.D.1.4 “VonMisesSR” criterion

This criterion is used to calculate Von Mises strength ratios. The relation between strength ratio, reserve factor and margin of safety is as follows:

S R = \frac{1}{R F} = \frac{1}{M o S + 1} .

This leads to the following expression for the strength ratio:

SR = \frac{FoS σ_{V M}}{σ_{a l l}},

in which

σ_{V M} = \sqrt{\frac{{(σ_{x x} - σ_{y y})}^{2} + {(σ_{y y} - σ_{z z})}^{2} + {(σ_{z z} - σ_{x x})}^{2}}{2} + 3 σ_{x y}^{2} + 3 σ_{x z}^{2} + 3 σ_{y z}^{2}} .

The arguments of the criterion are given in Table X.D.7. The method returns an Array of 7 elements according to Table X.D.8:

The four first elements correspond to the Result key on which the minimum margin of safety is calculated.
Then, Von Mises equivalent stress at critical location.
Then, one gives the critical (minimum) margin of safety.
The last element of the Array is a Result object that contains the margins of safety element-per-element, node-per-node...

Table X.D.7: Arguments of the “VonMisesSR” predefined criterion


Pos.	Name	Type	meaning	can be modified?


1	dB	DataBase	DataBase (or derived)	NO

2	fos	Real	factor of safety	NO

3	sigAll	Real	allowable stress	NO

4	stressRes	Result	Cauchy Stress Tensor	NO

Table X.D.8: Outputs of the “VonMisesSR” predefined criterion


Pos.	Name	Type	meaning


1	ElemId	Integer	Critical Element ID

2	NodeId	Integer	Critical Node ID

3	LayerId	Integer	Critical Layer ID

4	SubLayerId	Integer	Critical Sub-Layer ID

5	vmMax	Real	Von Mises equivalent stress tensor at critical location

6	srMax	Real	Critical strength ratio

7	srRes	Result	All the strength ratios that have been calculated

[next] [prev] [prev-tail] [front] [up]