Dynamic compression of metallic sandwich structures during planar impulsive loading in water

• Published in: European journal of mechanics, A, Solids Vol. 29; no. 1; pp. 56 - 67
• Main Authors: Dharmasena, K.P., Queheillalt, D.T., Wadley, H.N.G., Dudt, P., Chen, Y., Knight, D., Evans, A.G., Deshpande, V.S.
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier Masson SAS 01.01.2010; Elsevier
• Subjects: Exact sciences and technology; Fluid/structure interaction; Fundamental areas of phenomenology (including applications); Inelasticity (thermoplasticity, viscoplasticity...); Metal foams, lattices and honeycombs; Physics; Sandwich panels; Solid mechanics; Static elasticity (thermoelasticity...); Structural and continuum mechanics; Underwater impulsive loading; Vibration, mechanical wave, dynamic stability (aeroelasticity, vibration control...); Metal foams, lattices and honeycombs; Sandwich panels; Fluid/structure interaction; Underwater impulsive loading; Cell structure; Vibration; Sandwich structure; Momentum; Quasi static theory; Fluid structure interaction; Topology; Porous material; Modeling; Inelasticity; Truss structure; Hydroelasticity; Honeycomb structure; Corrugated surface; Pulse response; Stainless steel; Metal foam; Dynamic model; Crush; Dynamic load
• ISSN: 0997-7538; 1873-7285
• DOI: 10.1016/j.euromechsol.2009.05.003

The compressive response of rigidly supported stainless steel sandwich panels subject to a planar impulsive load in water is investigated. Five core topologies that spanned a wide range of crush strengths and strain-dependencies were investigated. They included a (i) square-honeycomb, (ii) triangular honeycomb, (iii) multi-layer pyramidal truss, (iv) triangular corrugation and (v) diamond corrugation, all with a core relative density of approximately 5%. Quasi-statically, the honeycombs had the highest peak strength, but exhibited strong softening beyond the peak strength. The truss and corrugated cores had significantly lower strength, but a post yield plateau that extended to beyond a plastic strain of 60% similar to metal foams. Dynamically, the transmitted pressures scale with the quasi-static strength. The final transmitted momentum increased slowly with core strength (provided the cores were not fully crushed). It is shown that the essential aspects of the dynamic response, such as the transmitted momentum and the degree of core compression, are captured with surprising fidelity by modeling the cores as equivalent metal foams having plateau strengths represented by the quasi-static peak strength. The implication is that, despite considerable differences in core topology and dynamic deformation modes, a simple foam-like model replicates the dynamic response of rigidly supported sandwich panels subject to planar impulsive loads. It remains to ascertain whether such foam-like models capture more nuanced aspects of sandwich panel behavior when locally loaded in edge clamped configurations.