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
- re-enforcing bar testing – in the steel/construction industry
- pre cracking fracture toughness specimens