Papers by Author: S. McKown

Abstract: This paper discusses the penetration behavior of fully supported sandwich panels with micro-lattice and foam cores, and composite skins. This behaviour is of importance during foreign object impact and perforation of sandwich structures. Experimental results are given for quasi-static penetration of micro-lattice and foam blocks, and it is shown that these two cellular materials are comparable. Experimental results are also given for drop weight penetration of fully supported skinned panels, and it is shown that skin failure and core penetration are also similar for the two core materials. It is concluded that there is scope for improving the performance of micro-lattice structure and so making such material superior to that of aluminium foam.

Abstract: The paper describes mechanical property tests on a Concorde aircraft tyre rubber. The tyre rubber is taken from the tyre tread, and consists of nylon reinforcement, laid up in an angle ply form. The constitutive behaviour of the rubber is characterised using the Mooney Rivlin approach, in which deformation is expressed in terms of strain energy. Static and dynamic tensile tests are conducted along the major reinforcement and minor reinforcement axes in the plane of the tread, and compression tests are conducted through the tread thickness. This data is then input into a finite element model of the tyre, using DYNA.

Abstract: Material properties are required for the numerical simulation of the impact progressive collapse of metal foam cored polymer composite sandwich beams, using LS-DYNA. As far as the metal foam, Alporas, is concerned, multi-axial tension and compression data is required. This includes large scale crush and tensile rupture. An Arcan test fixture was developed, in which a sample of foam can be subject to tensile and shear deformation simultaneously. The data was also used to calibrate the crushable foam material model in LS-DYNA. For the skin, tensile and compression data was generated for a cross ply glass fibre thermoplastic laminate. The data was then used to calibrate the composite damage material model in LS-DYNA. Inclusion of calibrated material models into the simulation of the progressive collapse of metal foam cored composite sandwich beams will be briefly discussed.