Set the force from impulse hammer as a master and acceleration from accelerometer as a response to measure the frequency response function.
Acceleration/ Force (accelerance) can be obtained from the above.
The mechanical impedance is force/ speed. To obtain it, convert acceleration to speed by single integration and calculate the inverse number of it.
Select the single integration (1/jw) in the frequency integral calculation of analysis setting and turn ON the “Reciprocal calculation function” in the frequency response function calculation.
The order of calculation
1. Frequency integral calculation
2. Reciprocal calculation
Indicator of dynamic characteristic
| Definition | Name | Unit (SI) | Analysis function to be used |
|---|---|---|---|
| Acceleration/ force | Accelerance (Inertance) | m/(Ns2) | - |
| Speed/ force | Mobility | m/(Ns) | 1/jw(single integration) |
| Displacement/ force | Compliance | m/N | 1/jw2(double integration) |
| Force/ acceleration | Apparent mass | Ns2/m | 1/H(reciprocal calculation) |
| Force/ speed | Mechanical impedance | Ns/m | 1/jw, 1/H (Signal integration, reciprocal calculation) |
| Force/ displacement | Dynamic stiffness | N/m | 1/jw2, 1/H(Double integration, reciprocal calculation) |
Revised:2017.08.31
