Problem

The following data were obtained from a creep test for a specimen having a gage length of...

The following data were obtained from a creep test for a specimen having a gage length of 2.0 in. and an initial diameter of 0.6 in. The initial stress applied to the material is 10,000 psi. The diameter of the specimen at fracture is 0.52 in.

Length Between Gage Marks (in.)	Time (h)
2.004	0
2.010	100
2.020	200
2.030	400
2.045	1000
2.075	2000
2.135	4000
2.193	6000
2.230	7000
2.300	8000 (fracture)

Determine

(a) the load applied to the specimen during the test;
(b) the approximate length of time during which linear creep occurs;
(c) the creep rate in and in %/h; and
(d) the true stress acting on the specimen at the time of rupture.