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The programme is an introduction to vibrations dealing with both damped and undamped spring/mass systems. Much of it is shot at a British Leyland test rig and track.
Metadata describing this Open University video programme
Module code and title: T232, Engineering mechanics: solids
Item code: T232; 07
First transmission date: 31-08-1980
Published: 1980
Rights Statement:
Restrictions on use:
Duration: 00:24:00
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Producer: Martin Wright
Contributors: Tony Bright; Dudley Thompson
Publisher: BBC Open University
Keyword(s): Oscillating systems; Resonance; Suspension test rigs; Vibrations
Footage description: Shots of Dudley Thompson driving a car along a British Leyland suspension test track. He switches to another car in which the suspension is much less damped and drives down the same track. Commentary by Thompson. Tony Bright, surrounded by several vibrating toys, points out the various modes of oscillation which vibrating systems are subject to. With the aid of an animated diagram of a spring/mass system, Tony Bright points out that a restoring force is essential to all oscillating systems. He goes on, again with an animated diagram, to show how the behaviour of the oscillating system can be illustrated on a displacement time graph. Film shots of the Tacoma Narrows Bridge disaster, of a model suspension bridge in a wind tunnel and of a tall chimney swaying in the wind. Tony Bright points out the need for engineers to take vibration into account when designing structures. Tony Bright goes on to introduce the concept of damping in oscillating systems. He attaches a variable damper to a spring/mass system and demonstrates the effect of various levels of damping. An animated diagram also illustrates the effect of damping. Shots of a Rover car on a suspension test rig. Dudley Thompson explains how vibrations through a car's suspension system are analysed here. Shots of oscilloscope traces which show the response of the car to road shocks. Tony Bright operates a vibrating system in the studio which has a continuous sinusoidal input. Both the input and the output responses are shown on an oscilloscope. Bright gradually increases the frequency of the input vibration and notes the output response, particularly the peak of extreme oscillations called resonance. He explains that engineers generally represent this phenomenon on a graph as a transmissibility curve. Dudley Thompson tries this experiment with two cars on a test rig which are damped to a different extent. He notes the effect of the damping on the transmissibility curve. Tony Bright sums up the programme and Dudley Thompson shows one final example of vibration problems in an engineering system. He looks at a car radiator on which the honeycombe edges failed after quite a short period and explains what the engineers did to cure the problem.
Master spool number: HOU3376
Production number: FOUT068S
Videofinder number: 2237
Available to public: no