Smartphones and bouncy structures – what do they have in common?
Until recently, nothing – but we hope that’s all about to change. A group of engineers at Expedition have recently been spending their nights and weekends developing an app for Android devices, that uses the in-built accelerometers of your smartphone to provide a simple, but powerful tool to test the dynamic performance of structures.
The trouble with designing for structural vibrations is that it’s quite arbitrary. Unlike other phenomena, like wind or gravity, we don’t tend to have an intuitive feel for what a certain level of acceleration actually means, nor do we have any real idea of how our ‘as-built’ structures perform in real-life as compared to our analysis models, as these are rarely tested (because it costs too much).
Usually, testing of built structures is only undertaken for specialist uses (such as laboratories), or if something has gone clearly wrong! So as designers all we can really do is blindly trust our computer outputs and hope for the best!
What we felt was missing, was a simple tool that enables designers to close the feedback loop, and allows other construction professionals to develop a better understanding of vibrations generally. So we set about trying to create this simple tool, and want to share what we’ve come up with so far – the Vibrate It app. This clever little bit of software uses the in-built accelerometers of your smartphone to record vibrations, then takes care of the complex post-processing to provide a clear visual output. For the technically interested users, the raw and processed data from each test can be captured for further viewing/scrutiny outside of the app. However the app is purposed for a broad audience – not just technical engineers – and we think it’s this aspect that is most exciting.
But why would non-engineers want to test structures for vibration? Assessment of vibration problems is widely accepted as a highly subjective science, in no small part due to the fact that everyone perceives motions differently, just as with our other senses. We believe our app embraces this subjectivity by creating a platform for a broader audience to understand the issue and engage in a more meaningful dialogue with the engineer, and we hope that this will help lead to better design.
The technical stuff is still important – we are currently working on a short user manual that will delve further into the inner mechanics of the app – but in simple terms, what we have found is that for a range of common structures we can use the processing power and intelligent hardware of modern smartphones to perform tasks that have until now been reserved for specialist vibration monitoring equipment (which require expert consultants to operate!).
Of course, there will always be a place for specialist knowledge and fancy equipment. We don’t see our app intruding on this space, rather as a complimentary tool. For specialist structures (laboratories, operating theatres, wards etc.) the smartphone is simply not adequate, nor is it adequate for more complex structures… for the rest: lightweight stairs and floors, bridges, trampolines and bouncy castles, the Vibrate It app is perfectly suited.
We are proud to release Beta Version 1.0 of ‘Vibrate It’ for Android for free, and hope that it will be useful… Let us know what you think.
Download the app from Google Play here.