Bringing Internet of Things to bolted connections

Bolted joints in critical applications need to be regularly inspected and maintained in order to ensure that they function as intended. Loss of preload in bolted connections is a naturally occurring and well-known phenomenon.

The inspection intervals can vary depending on the application. For some it could be as frequent as once a day; for some others it could be monthly or yearly. Often, this is mandated and regulated by independent authorities.

Inspection today is a manual activity performed in the field, and poses several challenges. Imagine an offshore oil platform that has a hundred thousand bolts in hard-to-reach places that need to be inspected over a 5 year period. Or a wind turbine with giant blades, high above the ground.

Inspection and maintenance operations have to be performed by trained professionals, and often under hazardous conditions. The amount of time and money spent on inspecting and reporting on critical applications globally is staggering. Additionally, there is no simple way to measure the bolt preload; the integrity in the bolted joint can at best be estimated. Therefore, every year, there are a large number of incidents resulting in breakdowns, stoppages, or worse, human tragedy.

While this disruption resulting in lost revenue and adverse publicity is unacceptable, it has been hard and costly to avoid. Until now. StrainLabs’ sensor technology brings the Internet of Things to bolted joints and allows for smart monitoring – completely redefining inspection, maintenance and reporting.

How StrainLabs’ sensor technology works

When a bolt is preloaded by tightening, it elongates elastically. The elongation is proportional to the preload. Our sensor technology uses a LED to measure the elongation and thereby accurately determine the bolt preload.
All bolted joints have a minimum and maximum allowed preload level. If the StrainLabs sensor detects that a preload value is approaching a limit that is indicative of failure, it alerts the user.
The sensor transmits its data wirelessly to a gateway, which via GSM, Wi-Fi, Ethernet or other existing networks, uploads it to a cloud service.

The system pinpoints, monitors, documents and reports back on each individual bolt and issues warnings for corrections. This information is displayed on a screen
– computer or handheld device. The required action can then be taken. This means you only perform maintenance when it’s necessary; only on the bolt that’s about to come loose.

Technology of the future, applied to bolted joints

This is Swedish innovation at its best – advanced technology that comes to you through our development partner, the Saab Group. It gives you a quick, precise and reliable solution to critical bolted joint management.

This is the future – the Internet of Things that combines hardware and software with state-of-the-art LED technology and electronics into one smart system that helps you save cost and time associated with inspection, and removes all risks associated with manual inspection.

A sensor embedded into a cavity in the head of the bolt monitors preload and temperature. When it detects that a bolt is about to come loose, it alerts the user and preemptive action can
be undertaken.