Vibratec has just finalized the installation of heavy gym floors for Zengun. The floating floors are spring supported concrete slabs and the gym is situated on the 8:th floor (the picture shows Vibratec’s spring battens). The top concreting has just been finalized. Vibratec has also installed the elastically suspended heavy ceilings and absorbent panels.
After a recent renovation of the 1929 Årsta bridge in Stockholm an increase of noise was observed. Vibratec Akustikprodukter AB has been awarded a multi-step project to mitigate the noise by use of constrained layer damping (CLD). Step one is to investigate the noise radiation from the bridge structure, and the partial contributions from deck, girders, wheel/rail contact etc. This involve vibro-acoustic modelling by Statistical Energy Analysis (SEA), lab testing of various CLD configurations at different temperatures, as well as similar CLD tests on a mock-up plus noise and vibration measurements on the actual bridge.
Vibratec has developed a tool for AVMs to help engineers in the design stage.
This app is specifically developed to dimension an anti-vibration mount (AVM) with Vibratec’s all-metal elastic elements. Simply enter the static load to be applied on the AVM and the rotational speed of the equipment mounted on top of the AVM.
The “AVM-tool” app will then show you the insertion loss, resonance frequency, deflection and needed dimensions.
It is both available in App Store (IOS) and Google Play (Android)
In Stockholm a new grand building landmark has arisen; the Royal Music Academy of Arts. The 14 800 m2 building has been built by NCC and it consist of rehearsal rooms, auditoriums, recording facilities etc. Vibratec has supplied 1075 pcs floor battens and 1125 liter NoiseKiller damping glue to the project.
At the new Rubart power station in Kansas electricity is generated by 12 Caterpillar engines. The air intake filers to the engines where originally designed for another slightly smaller engine type, so after start-up it turned out the larger air flow caused resonances in the steel plates of the filters. The vibration levels where considered to high, not only causing noise but also risk of fatigue and cracks in the steel plates. A requirement of 6 dB IL was set. Vibratec proposed a solution to solve the problem without changing filters and without risking power drops from the station. This solution was to add damping and mass to the filter plates by means of introducing a constrained visco-elastic layer. To have a solution with good characteristics during both winter and summer time required a “matrix” of different types of visco-elastic mats. A lot of tests and modelling was done before the optimal solution was found. Vibratec did the installation on site in Kansas during Nov-Dec 2015 and the final hand-over and approval was done in January 2016.
The method of surface treatment of our wire rope isolators has been changed. We have replaced the so-called hexavalent chromium (Cr+6) in the plating process with E-clps 3+, which is a more environment friendly process and according to EU-regulation RoHS.
The new Cr+3 plating process results in equivalent plating rate, hardness, and current efficiency compared with Cr+6 plating, and will not effect the price. However, with the new surface treatment the wire rope isolator will have a white “natural” aluminum color instead of the previous yellow.
Systemair India Pvt. Ltd. (100% owned subsidiary of Systemair AB, Sweden) has just come up with a ultra-modern laboratory to test air and sound performance. The new laboratory has a pressure chamber and an acoustic chamber and is thus sensitive to vibrations and structure borne noise. The complete lab weighs 145 tons and is standing on 56 vibration isolators in kevlar reinforced rubber resulting in a resonance frequency below 10 Hz. The special isolators were casted into the concrete floor and later jacked up when all walls, ceiling etc was in place. The placement of the isolators was carefully calculated to ensure equal load distribution on the isolators.
Vibratec’s agent Prodiscom spent 11 days on the site to supervise and assist during installation, concreting and final jack-up. The lab, being a part of Systemair’s latest technology centre, is situated i Noida in the province Uttar Pradesh.
The quarter Västända is under construction during 2015. The buildings (that will house 180 appartments) are bounded by the roads Årstavägen, Johanneshovsvägen and is also forming an overall decking of the tramway Tvärbanan. The complete buildings therefore had to be vibration isolated from the ground. This was done by introducing elastic trips between the load bearing concrete walls and the building foundation soles. As elastic materials where used mats of ReguFoam in different widths and stiffness’s to ensure proper performance.
Contractor for the project is JM Entreprenad AB