As the title of the blog post states it has been a long time since my last post, but things have been quite busy here at INSIST! To start with the production of the steel foam sandwich specimens comprising DC01 steel face plates and steel hollow spheres.
We also had the receipt of prototype SAS (Steel face -Aluminium foam-Sandwich) of two types (SAS 3/30 and SAS2/20) from Havel GmbH. These were cut to size and prepared for testing.
The next challenge was to paint the foam surface white and apply a black speckle pattern in order to use Digital Image Correlation techniques for measuring surface strains for the different experiments. The surface voids and sphere curvature posed some difficulties but after several trials we were able to get some good results.
Our first tests were monotonic compression tests of steel hollow sphere blocks in order to determine the compressive Young's modulus, Poisson ratio, compressive yield strength and strain energy absorption. Preliminary results were present at the 2nd International Conference on the Mechanics of Composites in Porto in July.
The test will continue through the summer with monotonic 4 point bending of both SFS and SAS sandwich specimens, followed by fatigue testing later.
Lastly the INSIST team has been awarded an Institution of Structural Engineers Research Grant to undertake experimental testing for the evaluation of damping of steel foam sandwich structures. The project will commence towards the end of the INSIST project and run for 6 months.