yes, vibrations the same for each test. The company has something they call a junker which is a machine that is able to create shearing forces to duplicate vibrations over time but within a much shorter period. they've tested a number of fasteners and locking devices.
Their double nut test was pretty interesting as well.
I think most of what you guys are trying to apply involves misunderstanding and misapplication of engineering and scientific fact.
1) Traditional split lock washers do not hold anything via spring action. Therefore any reference to the spring nature of the lock washer attempting to hold anything is pure misapplication of the design intent and therefore results in fallacy, regardless of who tests it. A traditional split washer is made of a type of hardened or spring steel and cut at a diagonal such that two sharp opposing "blades" are produced. These "blades" are intended to bite into the softer clamped and clamping materials creating a bur as they are tightened. It is this bur that is intended to prevent or at least delay loosening. The spring action is only there to provide enough tension to generate the bur that will help hold the fastener in place. For this reason split lock washers are also inneffective when used on hardened nuts. Split washers also cause damage to the nut and surface when installed and therefore should not be used where frequent assembly/disassemble is required. Split lock washers are also not generally used in applications subject to extreme vibration.
2) The ability to resist loosening under conditions of vibration is a misnomer and the use of vibration testing to determine the holding ability of a faster is also largely fallacy. To the untrained mind it is an impressive demonstration, but for someone able to think things through, typical vibration testing is little more than a circus side show. Testing a fastener to the point of failure does not necessarily provide any useful data for the actual application of the fastener. For example, in order for any loosening to occur, the forces of vibration and the resulting load placed on the fastener have to be high enough to temporarily unload the threads. The threads simply will not back off if the fastener is sufficiently strong enough and torqued correctly to the point where tension can be maintained at all times. If you are experiencing unloading of the faster to the point that it unscrews, even under conditions of vibration, you have either overloaded the bolt or you have not sufficiently torqued it. Case in point: Connecting rod bolts. Think about this for a moment.
Bolt locking devices of any kind should not generally be used to hold a nut in place! To presume to think that a locking device is necessary most often demonstrates a lack of understanding of the engineering involved and an underestimation of the size or quality of required fasteners. This does not mean that locking methods should not be used, but it does mean that a locking device should not be used as a primary holding device.
One proper use of locking devices is when the clamped component is insufficiently strong to hold the required clamping force of the fasteners. There are many cases where the amount of torque required to properly stress the fastener would damage the component (like exhaust headers, for example). In this case double nut (using two nuts of equal size) is an appropriate solution.
The whole topic is much more complex than could be covered here, and I am only presenting a few tidbits for your consideration. If properly installed, split lock washers on the driveshaft loop is an appropriate application. Nylock nuts in this case would be better though because clamping force in this case is more or less irrelevant and so even if the bolts are not tightened properly, the Nylocks will not rattle off. The only thing the bolts are doing in this case is connecting the two halves of the loop. As long as they don't fall out completely, they will continue to do their job, and the amount of clamping force provided by the fasteners is largely irrelevant.