ultimate strain of SS?
ultimate strain of SS?
(OP)
I've been looking for the ultimate strain for some different materials and having trouble. Particularly 13-8 H1000, MIL-HDBK-5 has a stress strain curve but it only ges up to about 1.2% strain. They also have a "full range" but it shows the same Ramburg-Osgood curve and then at 1.2% strain the curve starts coming down. This seems a little low for a material which is considered ductile. Is this value right or is there another source I can check for a better stress strain curve. As an aside mil-hdbk says the fracture strain is 10%, which I guess I believe a little more than the ultimate strain.
Thanks
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RE: ultimate strain of SS?
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RE: ultimate strain of SS?
The fracture strain is the same as the ultimate strain, which is required to be 10% for PH13-8Mo according to AMS 5629 (Table 2.6.6.0(b) on page 2-158 of MIL-HDBK-5J). The full range curves shown in Figure 2.6.6.1.6(c) show the same thing: the H1000 specimen fractures at an ultimate strain of ~ 0.10. Keep in mind that these are engineering stress-strain curves, and that the shape of the true stress-strain curve will be different.
RE: ultimate strain of SS?
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Tensile elongation (total strain to failure) in 2" gage is 14% typical for an H1100 condition.
RE: ultimate strain of SS?
I'm doing an elastic / perfectly plastic analysis and I don't think I can assume I carry the full plastic load all the way out to fracture since I'd have necking after the ultimate strain is reached.
RE: ultimate strain of SS?