Resonant test machines
Resonant test machines are ideal where a large number of cycles is required, with typical test frequencies in the range 80-300Hz.
Resonant machines are very energy efficient with power requirements on a test of 10kN-100kN at 120Hz, for example, in the order of 600 watts. Contrast this with a servo hydraulic machine which would test at around 30Hz and require in excess of 20 kilowatts.
The main application is HCF (high cycle fatigue) in the following areas
- materials testing – research into material properties
- bolt and fastener testing – often in the aerospace industry
- reinforcing coil and reinforcing bar testing – in the steel/construction industry to BS 4449:2005+A3:2016 high tensile rebar
- pre cracking fracture toughness specimens