The reason for monitoring shock and vibration is because of the potential adverse effects on buildings, their contents; or to monitor valuable products in transit; or for condition monitoring of rotating equipment. The sources of shock and vibration are very diverse ranging from construction works [piling, ground works, tunnelling, fracking, etc.], blasting, road traffic, other transportation modes, etc. Or in the cases of products in transit from transport or handling/mis handling.
For structural monitoring, a large number of international standards document permitted or recommended levels. Some principal standards are:To say that the standards require interpretation is an understatement and in many instances are littered with caveats along the lines of “ …the levels suggested …” or “… some data suggests..” !
Some major infrastructure companies have specified the circumstances under which monitoring is required for works in proximity to their installations, egRemote monitoring of Shock and Vibration is increasingly common in tender specifications for major works, and vibration and shock monitoring is referred to in Eurocodes.
For impact on structures the principle measure of interest to engineers and consultants is PPV – Peak Particle Velocity. PPV is defined as the maximum instantaneous peak of the vibration signal, measured in m/s or mm/s [or inches/s in the USA]. For impact on humans PPV is not helpful as it takes some time for the human body to respond to vibration signals. Because the net average vibration signal is zero the root mean square[RMS] is used to describe a smoothed amplitude. These are shown graphically in Figure 7-2 [courtesy of ntl.bts.gov/data/rail05/ch7] Most of our customers are interested in PPV, monitoring impact on structures or buildings. According to several of the standards the potential for structural damage is correlated to PPV [mm/s] within certain frequency bands:
The winter storms early in 2014 were some of the most severe recorded in South West England. Coincidentally during this period Plymouth University’s School of Marine Science and Engineering have been using vibration monitoring equipment from Caption Data limited, to measure the dynamic structural response of Eddystone Lighthouse’s tower under various stress loads. Eddystone Lighthouse was built on a dangerous rocky reef 13 miles south west of the city of Plymouth over one hundred and thirty years ago. Read More
With an ever increasing list of checkboxes, hoops to jump through, safety requirements, along with focus on sustainable and socially friendly operations in civil and structural engineering – remote monitoring systems can offer a range of benefits. Remote monitoring systems can offer real time access to data from construction and groundwork activities such as piling, drilling, dewatering, tunnelling, blasting…. Read More
Daily goods become damaged due to improper handling, humidity, faulty packaging, theft, misuse or other incorrect handling. Damage of your goods results in:
Two earthquakes struck in New Zealand and coincidently a New Zealand based customer had the RDL//Vibe online, testing for vibrations, and what better clarification that the shock and vibration monitoring system works than capturing vibrations during two earthquakes within 50km. Read More
A robust self-powered remote monitoring system which continuously checks shock and vibration levels while transferring data on any “events” exceeding your pre-set limits to the CDLSmartHub
MSR Dataloggers – miniature dataloggers for acceleration, vibration, pressure, temperature, humidity, voltage, light and more