material non linearity
material non linearity
(OP)
Dear all,
Can any of you help me to interpret the results of material non linearity analysis run on NASTRAN SOL 106.Material is AMS 4010 and properties are UTS:510 MPa, YEILD:450 MPa & ductility is 9%.As explained in nastran, i have input a stress-strain curve.My first point is (0,0) & second point is (450,0.006) & inbetween i have 6 more values and last value is (510,0.009).Since ductility is 9%, my last strain value 0.009 strain or 9000 micro strain (have i given the input in a right way considering ductility ?). No temperature effect is considered.Run was successful.Linear static had shown 560 Ma (Max Pri) at critical section of the component. So a non-linear was attempted.nonlinear showed 495 MPa at the same critical section but strain were 0.011 or 11000 micro strain.
has the component failed..? results were plotted from non-linear stress and strain tensor, Result strain should be compared against what allowable strain..? or non-linear elastic modulus...?
kindly help me out...
Thanks in adavance
with kindest regards
Can any of you help me to interpret the results of material non linearity analysis run on NASTRAN SOL 106.Material is AMS 4010 and properties are UTS:510 MPa, YEILD:450 MPa & ductility is 9%.As explained in nastran, i have input a stress-strain curve.My first point is (0,0) & second point is (450,0.006) & inbetween i have 6 more values and last value is (510,0.009).Since ductility is 9%, my last strain value 0.009 strain or 9000 micro strain (have i given the input in a right way considering ductility ?). No temperature effect is considered.Run was successful.Linear static had shown 560 Ma (Max Pri) at critical section of the component. So a non-linear was attempted.nonlinear showed 495 MPa at the same critical section but strain were 0.011 or 11000 micro strain.
has the component failed..? results were plotted from non-linear stress and strain tensor, Result strain should be compared against what allowable strain..? or non-linear elastic modulus...?
kindly help me out...
Thanks in adavance
with kindest regards





RE: material non linearity
The allowable strain is whatever has been decided - some components can have zero plastic strain, some can have any plastic strain that does not cause fracture.
RE: material non linearity
Your linear analysis should have caught that - all your deflections would be only 10% of what is reasonable.
Cheers
Greg Locock
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RE: material non linearity
RE: material non linearity
RE: material non linearity
And as Mr.Greg mentions, material is more brittle considering the difference between Yeild and UTS
Yes rb1957, as i understand,NASTRAN extrapolates the last two stress-strain values if solution dose,nt converges within the given values.
RE: material non linearity
No, 9 % elongation is 0.09 engineering strain.
Your last message suggests you are confused on what you are doing. I can tell you with certainty that a data point of (510,0.009) is nonsensical on either a percent or absolute scale for stress-strain.