Strain gauges measure surface strain at different points of a test piece – in this case of the plane the strain is a measure of how much something has stretched in relation to its original length, in engineering terms e÷l (e = extension, l = original length, so strain= e ÷ l).
The aircraft manufacturers’ engineers have been up this week to mark out where the strain gauges need to go on the plane – there’ll be 17 in total. Jake has then been removing the paint and preparing the surface of the plane where the gauges will be located. The two Steve’s are on holiday at the minute but when they come back they’ll bond all the little strain gauges on to the plane’s surface.
We’ve also been working on getting the strong floor prepared to ensure all the mounting points are correct. Last week we set up the first mounting point as a datum (a standard position or level that measurements are taken from) and then we’ve measured all the other mounting points from that. We’ve marked some datum lines on the floor – there’s a datum line and a central line – and everything we’re doing is referenced from these points using triangulated measurements – this will make sure we’re millimetre perfect. It the fits not right we’ll not be able to assemble the plane on the mounts. It’s all been checked and double checked and even checked again and we’re bang on (hopefully!).