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Description
Several vibrating systems of single degree of freedom are demonstrated. Dimensional analysis is then introduced to examine systems with more than one degree of freedom.
Several vibrating systems of single degree of freedom are demonstrated. Dimensional analysis is then introduced to examine systems with more than one degree of freedom.
| Module code and title: | T231, Introduction to engineering mechanics |
|---|---|
| Item code: | T231; 08 |
| First transmission date: | 18-05-1975 |
| Published: | 1975 |
| Rights Statement: | |
| Restrictions on use: | |
| Duration: | 00:24:28 |
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| Producer: | Peter Clark |
| Contributor: | Vernon Marples |
| Publisher: | BBC Open University |
| Keyword(s): | Chladni experiment; Degree of damping; Dimensioanl analysis; Electro-magnetic generator; Freedom system; Plate; Salt grains |
| Footage description: | Pip Youngman demonstrates the home experiment kit set up for the vibrations experiment. Vernon Marples vibrates a simple block and spring system. He shows that the system is not one of single degree of freedom because of the rotational as well as vertical motions. Marples with a modified version of the above system which has rotational tendency removed (a sprung trolley on a ramp). He explains why it behaves as a single degree of freedom system. Marples demonstrates another model in which rotational tendency has been eliminated and which behaves like a single degree of freedom system. Marples next demonstrates the torsional rod experiment: this also behaves like a single degree of freedom system. He goes on to explain how the natural undamped frequency of vibration is calculated. The equations are captioned. Marples sums up the properties of single degree of freedom systems. He goes on to show that the vibrational effects do not need to be centred on one point of the system but can be spread throughout the system. Marples uses a cantilever to demonstrate. Marples uses a vibrating cantilever attached to an oscilliscope to demonstrate the effect of damping on a vibrating system. He shows how the degree of damping can be recorded. Marples looks at dimensional analysis in the context of vibrating systems. He demonstrates using aluminium Cladni plates which vibrate at set frequencies. Marples sprinkles salt crystals on the plates and these move into characteristic patterns depending on frequency. Marples performs the experiment again using plates with one dimension changed. The patterns for the above frequencies are now also changed. |
| Master spool number: | 6HT/71431 |
| Production number: | 00525_5108 |
| Videofinder number: | 2224 |
| Available to public: | no |
