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Tangent Modulus (ls-dyna) — Ansys Learning Forum

# Tangent Modulus (ls-dyna)

Member Posts: 14
edited March 26

Hi everyone!

I want to obtain tangent modulus from the results of my uniaxial tensile test. I find the picture below on the internet. However, as you can see, there are infinite number of points where you can calculate the slope. To obtain the tangent modulus of my material, which point's slope is required?

In brief, how can I calculate the etan (tangent modulus) value from my diagram?

Tagged:

• Member Posts: 102

E_tan_Calculated / E ratio may be closer to an Elastic-perfectly

plastic case.

E_tan_Calculated = [(1+%EL/100)*S_ult - S_yield ]/ [(ln(1/(1-%RA/100)))- (S_yield/E)]

%EL= % Elongation

%RA= % Reduction in Area

E = Modulus

The strengths are self Explanatory.

If you don't know the %RA you can approximate by

%RA =200*%EL/(100+2*%EL)

Cheers, Ram

• Member Posts: 102

E_tan_Calculated / E ratio may be closer to an Elastic-perfectly

plastic case.

E_tan_Calculated = [(1+%EL/100)*S_ult - S_yield ]/ [(ln(1/(1-%RA/100)))- (S_yield/E)]

%EL= % Elongation

%RA= % Reduction in Area

E = Modulus

The strengths are self Explanatory.

If you don't know the %RA you can approximate by

%RA =200*%EL/(100+2*%EL)

Cheers, Ram

• Member Posts: 14
edited April 5

Dear sir,

Thank you very much for your help. I am very grateful to you.

Could you please recommend a source to me where I can also see those formulations?