The general concept of the tests is that the frequency and the stroke (amplitude) with limits based on the fluid flow of the actuator, the maximum force on the damper seals (7000 lbs), and maximum velocity (7 in/s).
The special aspect of this damper is that it has a manual pin valve not normally found on dampers installed in the field. This allows us to control the damping coefficient by opening and closing this bypass valve in addition to the main setup. What was great was that the results when the bypass valve was fully closed were in the correct range as calculated by the imperial equations given by the manufacturer.
This is a video from Tuesday of the damper in the test frame being loaded at 2 Hz and 1 inch stroke.
Something that was interesting was a type of 'shouldering' at the midpoint of the sine wave which reduces the tension force resisted by the damper compared to the compression forces. This was expected by the manufacturer since compression is more of a concern so the mass/piston doesn't slam into the support.
Doing the tests today, I did as many tests as possible before it started getting warm. Best plan of attack was to do two of each valve position for each test, starting with the valve open so that the highest force (most likely to heat) would be last.
After prelim work, seems the temperature of the damper makes a huge difference (not just minor) on the performance, so a sensor or infrared gun from the outside is probably the best that can be done with the time given.
Last and current issue: computer in the lab has Excel 2002, can't be read by Excel 2010 or 2011. Will work with different file format but that's a tomorrow problem!
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