At #OrthotropicEngineering, our mission is to supply our customers with high-quality composites design and analysis services. Most of what we do is desk-based, making regular use of our CAD and FE software whilst not forgetting the value of more traditional analytical methods when the occasion calls for it. And of course, there are always moments when the solution to a problem requires a more practical approach; fortunate then that our engineering office is supported by the workshop and test facilities needed to manufacture and evaluate composite testpieces and small prototypes.
As part of a recent project it was necessary to supplement our design work with some targetted testing: We generally aim to design out tensile stresses running though the thickness of #compositelaminates as this is a weak direction, however, there are occasions when - as a consequence of fixed geometry or some other aspect of the design - they are unavoidable and must be understood, quantified and carefully managed. It's also at this point that we find the rulebooks and guidelines that govern many aspects of composites designs have very little to say, so we must generate our own data.
In this case, the through-thickness stresses arose due to the flexure of a curved laminate at a corner between two adjacent flat panels. Various constraints on the design meant that it wasn't possible to soften the transition, so our solution was to manufacture and test specimens correctly representative of the materials, geometry and loading in question, all in-house and (to keep the project moving) in a little over a week.
A contoured #GFRPpanel was manufactured by the #resininfusion method, then post-cured and cut up to produce individual specimens that were tested using bespoke fixturing - very pleasing to note that the failures occurred as and where expected in all cases, with a sharp crack and drop in load indicating the propagation of the anticipated delamination - and a valid test! Lastly, results were correlated with the output of an #FEAstudy to enable a safe design allowable value to be established.
We love a challenge at Orthotropic and are happy to deploy an integrated design/analysis/test approach as part of the solution. Please do get in touch to discuss your #CompositesEngineering requirement - we'll be very pleased to help!