About this project
Vicoma received an interesting assignment from one of its regular customers in the heavy industry. A crane on the production site vibrates annoyingly in the direction of travel and this is not pleasant for the crane operator. Although the vibrations fall within the health and safety limits, the client wanted a solution for this problem.
Project: crane track girders and rails cause annoying vibrations in the cabin
The crane has a span of 24 metres, with the cabin hanging 8 metres below the crane beams. The crane track girders and rails are responsible for the vibrations. However, adjusting these is not an option. However, adjusting these is not an option. For the research, a plate-and-bar model was made of the cab car and part of the crane girder.
Vicoma’s role: FEM model gives insight and leads to two possible solutions
Using measurements, a FEM model gave Vicoma’s engineers more insight into adjustments to the crane construction and their effect on vibrations. Two solutions to reduce vibrations were identified: adding mass and using a tuned mass damper, a mass-spring system tuned in one frequency range to dampen vibrations. Adding mass increases the amount of mass in motion, which reduces vibrations. This option is not possible due to the large amount of mass required, so a tuned mass damper was chosen. This option is not possible due to the large amount of mass required, so a tuned mass damper was chosen.
Result: vibrations reduced by up to 57 per cent
In the end, the critical mass was effectively reduced with the tuned mass damper, which is adjusted so that it does its work in the critical frequency. The result: the vibrations were reduced by up to 57 per cent, according to verification measurements.