Foundation and resonance
Determining critical speeds and frequencies
Every machine or structure has one or more resonance frequencies. However, most machines are designed in such a way that these frequencies do not coincide with the operating speed and therefore prevent mayor problems from occurring. However due to design or calculation errors or due to changes to machinery structure or operating speed, resonance problems do occur. With our vibration research we determine the critical frequencies and their influence on the vibration behaviour of the machine. If problems are present, we will advise you on the best way to make adaptations to your machine or foundation as a result of which resonance problems will be eliminated.
Variable speed drives are becoming more and more common throughout the industry. Besides the many advantages in process control and energy consumption there is also a disadvantage to a large operating speed area namely resonance. The resonance free area will to be have larger as well. Only too often we find resonance to be the cause of vibration problems.
Another frequently encountered problem is with those machines of which the operation speed has been increased in order to cope with higher production demands. Without changes to the structure of the machine, high vibrations or resonance are likely to occur.
Stiffness or mass
The resonance frequency of a structure or machine is mainly determined by the ratio between the different masses and stiffness of the supporting structure. In order to shift a resonance frequency, it is in most cases sufficient to change the stiffness or (modal) mass of the machine structure.
Van Geffen VMS offers a large variety of specialized vibration measurements that determine these critical frequencies. With a brief and specific recommendation we will indicate which practical solution is the most suitable in your situation.
Some of the technologies that are used for the foundation and resonance research: