Real(ish)-time views of run 554: 95:5 by vol OK#1:ice

(last updated 1600 hrs 3/18/08)

Conditions:    
P = 60 MPa, T = 223 K, s = 30 MPa step (1), started 1015 hrs 3/11/08  
1600 hrs 3/18: end of run. Average edot over past 2 days has been 4-6e-9/s, and was 0/s over past 7 hrs. Resolution is not better than ±5e-9/s because of the T problems.
0900 hrs 3/18: most of last night was fighting against a weak LN tank. Over the long, flat periods at >V0.00 motor speed was operator limited. There is a strong (but unprovable) possibility that none of this deformation was necessary from a creep standpoint, but was simply the machine compensating for T effects on gage zero, sample/vessel length, etc.
~2000 hrs 3/17: Another T event (!) at the little staircase, this only ~2 K warming. Too bad, because edot≈0 was starting to look like the norm.
0620 hrs 3/17: Most of this is recovering from T event in previous. Fully recovered by pt ~30500
1810 hrs 3/16: Significant warming event (~5 K) started at point ~26000 where speed stepped up to V0.03. Did not fully recover until well into next chart above.
1230 hrs 3/16: been steady-ish now for past 36 hrs at 1e-8/s. Total strain 0.075. May have to throw out all those theories about continuing to work harden...
2018 hrs 3/15: beginning of this segment include ~8-hr P drifting caused by intensifier topping out. Great operator skill kept this from disrupting the run.
0750 hrs 3/15
1823 hrs 3/14
0605 hrs 3/14
2200 hrs 3/13: start of step (1b), same conditions. Put in 100:1 gearing at point ~200, maybe a bit too soon, which leads to the sloppy looking edot. It looks worse than it is. Total strain 0.072, so there is strain enhancement from unloading and reloading.
1600 hrs 3/13: edot into e-9/s range; stop, unload to check s gauge zero drift [there was ~none] and rebound [there was a some, much more than 553]. Total strain at end of step (1a) is 0.070.
0630 hrs 3/13: Piston displacement capped itself most of the night at the V0.04 safety limit (edot≈2e-8/s) set by the operator. Not to be alarmed. Force (lower chart; sigma = 30 MPa is 0.0323 V at current value of strain) was never more than ~0.5 MPa below its 30-MPa setpt. Cause, I believe, is related to T control, and the effect of a 0.5-K change on the zero value of the force gage. By 0900 this morning sigma was back up to its setpt. It will take days to find out if this is still work hardening. Total strain is 0.070.
1745 hrs 3/12: Should be obvious where I switch to 100:1 gearing. Current edot down to 2-3e-8/s.

0630 hrs 3/12 : 20 hrs into step (1), chugging along at a smooth ~5e-8/s. I may switch to 100:1 gearing from 10:1. Total strain is 0.068. See "Today's epiphany" above.

 

Today's epiphany: it's impossible to assign absolute strain values to these low-ice content (0, 5%, maybe 10% samples)

View of 554, about 5 hrs into step (1).

Vertical axis is edot (i.e., motor speed. V0.05 = 0.05). Horizontal axis is time (1000 ≈ 3 hrs). In a few days this will be right down at 0.

Same as previous, different scale.

This and the shot below compare 5% water (here) to dry.

554 (95:5)

 

See how much sooner 553 drops to low edot?

553 (100:0)