Development of a test rig for a multiple-mass oscillator
Master thesis at the HTW Berlin – University of Applied Sciences
As part of his master thesis, student Tobias Hantke developed a test rig for a multi-mass oscillator that generates and maps frequencies that satisfy the system of differential equations.
Within the scope of this task, the student developed and manufactured a mobile deployable test stand. This generates and displays the normal modes of a multi-mass oscillator and the frequency response of a single-mass oscillator for the human eye. With the help of the test rig, students can also be taught practice-related topics (e.g. quarter vehicle model) in addition to theoretical knowledge.
A choice can be made between free and externally agitated oscillation. Independent of this decision, a “strongly” damped (Lehr damping dimension: 0.1 ≤ D ≤ 0.2) or “weakly” damped system (Lehr damping dimension D ≈ 0.00) can be tested. External agitation is achieved by converting the rotational movement of a cordless screwdriver into a translational movement. The system can be externally agitated with an excitation amplitude in the range from 1 mm to 24 mm with a step size of one millimetre. With the help of a measuring technique, the vibration patterns can be recorded, processed by an electronic evaluation system and then visualised. To illustrate the influence of the spring rate on the vibrating system, different spring rates (10 to 100 Newton per metre) can be selected. The oscillating masses installed in the test rig have a mass of roughly 330 grams each.
norelem supported the project with the following products:
- Fastening sets for straps und angles (10244-08)
- Swivel castors (95010-07525)
- Cube connector sets (10220-103)
- Pull handles (06916-01-2140084)
- Cover and adapter profiles (10045-084040×1000)
- Circlips for shafts (07330-030400)
- Deep groove ball bearing (23800-100301004)
- Plain bearings cylindrical (23730-00801010)