Model:Resonant Column Apparatus
Use:The GDS Resonant Column Apparatus (RCA) is used to excite one end of a confined solid or hollow cylindrical soil specimen. From the resonant frequency, small strain stiffness can be found. Used by both the advanced commercial laboratories and Universities
Standard:GBT 50123-2019
Product Code : S-RCA
The variation in these parameters with increasing strain magnitude allows engineers to conduct dynamic response analyses, such as those using finite element and non-linear analytical methods, which enable performance assessment of natural and engineered structures subjected to dynamic and cyclic loadings.
Key features | Benefits to the user |
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Current driven actuator using a transconductance power amplifier: | The impedance of magnet / coil devices change with frequency. At higher frequencies, using a constant voltage amplifier the current would be seen to reduce. As the torque is directly proportional to current, the torque will also reduce and a non-linear torque input would affect results. This effect is removed in the GDSRCA by using a current driven power amplifier. |
Designed to provide maximum rigidity: | Providing minimum losses and a more consistent frequency response. With no rigid support to the top cap it is completely free vibrating. |
Dedicated GDS RCA software is used for control and data acquisition of the RCA apparatus: | Simple automated tests ensures consistent results |
Low equipment damping: | The software switches the hardware to provide an ‘open circuit’ through the coils during free vibration decay, which prevents ‘back’ EMF generation and reduces equipment damping effects. |
Electro-magnetic drive system: | Which incorporates precision wound coils and composite sintered neodymium iron boron (NdFeB) “rare-earth” magnets. |
Internally mounted, counter-balanced accelerometer: | Used to measure vibratory response of the sample. |
Internal cell: | To surround sample with water, to avoid air penetrating the membrane. |
Operating Frequency (Hz) |
0 to 300Hz |
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Pressure Range (MPa) |
1MPa (Standard), 2MPa and 3MPa |
Sample Sizes |
50mm, 70mm, 100mm, 150mm |