Material Properties For A-516 - 70 1

[soljarag]

Hello, I was wondering if anyone knows any of the following specs

n, r, k, Poisson's Ratio , Yield Stress for A-516-70

if you need to know the thickness, base it off 1"

Thanks!

 

[CoryPad]

Yield stress is defined as 260 MPa minimum. All other variables are undefined. Poisson's ratio should be approximately 0.27. The other three variables will depend on microstructure and processing parameters. You should conduct lab testing to obtain these values.

Regards,

Cory

Please see FAQ731-376 for tips on how to make the best use of Eng-Tips Fora.

 

[JoeTank]

Yield is 38 ksi, Poisson's ratio is about 0.3. I don't even know what n, r and k stand for!!

Joe Tank

 

[metengr]

Joe;

Here you go, from ASM Handbook, Volume 14, Section on Formability Testing of Sheet Steels

Strain-Hardening Exponent. The n value, d ln T/d ln, is given by the slope of a graph of the logarithm of the true stress versus the logarithm of the true strain in the region of uniform elongation. For materials that closely follow the Holloman constitutive equation (see below), an approximate n value can be obtained from two points on the stress-strain curve by the Nelson-Winlock procedure (Ref 26). The two points commonly used are at 10% strain and at the maximum load. The ratio of the loads or stresses at these two points is calculated, and the n value and uniform elongation can then be determined from a table or graph. The accuracy of the n value determined in this way is ±0.02.

The n value can be determined more accurately by linear regression analysis, as in ASTM E 646. For some materials, n is not constant, and initial (low strain), terminal (high strain), and sometimes intermediate n values are determined. The initial n value relates to the low deformation region, in which springback is often a problem. The terminal n value relates to the high deformation region, in which fracture may occur.

true stress=k*(true strain)ⁿ

Plastic Strain Ratio. The r value, or anisotropy factor, is defined as the ratio of the true width strain to the true thickness strain in a tensile test. Generally, its value depends on the elongation at which it is measured. It is usually measured at 10, 15, or 20% elongation.

 

[JoeTank]

metengr,
Thanks. That was indeed informative, but now my head hurts! I'll copy this and tuck it away for later reference and give you another well-deserved star.

Joe Tank

 

[soljarag]

Yeah, thanks for the info guys!