Control of Sinusoidal Vibration Testing

Having discussed in ebook 18 the requirements, the standards, for sine testing, let’s now discuss the “doing,” the performing, the accomplishing of such tests. A few words regarding their purpose, such as identifying product resonances and possible fatigue failures. Why was manual control of sine testing not satisfactory? That era’s analog automation certainly helped laboratory performance. An oscilloscope warns the test engineer that his shaker’s waveform has become distorted, non-sinusoidal. Most attention is paid to today’s digital control of sine testing. “Remote control” enables the operator to leave his digital controller. The usual motion (displacement, velocity and/or acceleration) control of one’s shaker can endanger vibration-absorbing under-test products. Some labs alternate motion control with force control. Is response at your test article’s cg (or another location) specified?
Table of contents: 



19.1 Why perform sinusoidal vibration tests? 
19.2 Resonance search tests 
19.3 Resonance dwell tests – fatigue 
19.4 Manual control of swept-sine tests 
19.5 Sine testing automated 
19.6 Why the oscilloscope? 
19.7 Tracking filter 
19.8 Sine testing – digital control 
19.9 Remote control of shaker 
19.10 Shortcomings of motion control 
19.11 Constant motion not found in “real world” 
19.12 Tuned or passive vibration absorbers 
19.13 Crankshaft torsional absorbers 
19.14 Force controlled sine vibration testing 
19.15 Response control at CG 
19.16 Multiple control accelerometers 
19.17 Response control strategy