Multiaxial creep of low density open-cell foams

• Published in: Materials science & engineering. A, Structural materials : properties, microstructure and processing Vol. 540; pp. 83 - 88
• Main Authors: Fan, Z.G., Chen, C.Q., Lu, T.J.
• Format: Journal Article
• Language: English
• Published: Kidlington Elsevier B.V 01-04-2012; Elsevier
• Subjects: Applied sciences; Creep; Exact sciences and technology; Mechanical properties and methods of testing. Rheology. Fracture mechanics. Tribology; Metals. Metallurgy; Open-cell foam; Phenomenological constitutive model; Voronoi model; Voronoi model; Open-cell foam; Creep; Phenomenological constitutive model; Constitutive equation; Voronoï diagram; Open cell porosity; Cellular material; Creep rate; Multiaxial load; Finite element method; Phenomenological model; Three dimensional model; Elastoplasticity; Metal foam; Heat of adsorption; Heat transfer
• ISSN: 0921-5093; 1873-4936
• DOI: 10.1016/j.msea.2012.01.086

► A more reasonable modified foam creep expression is presented. ► A phenomenological constitutive model for multiaxial foam creep is deduced. ► FE results by random cell models are well captured by theoretical models. ► Foam creep deformation show high sensitivity to foam relative density.
Open-cell foams have wide applications in structural components, energy adsorption, heat transfer, sound insulation, and so on. When their in-service temperature is high, time dependent creep may become significant. To investigate the secondary creep of low density foams under multiaxial loading, three-dimensional (3D) finite element (FE) Voronoi models are developed. The effects of relative density, temperature, cell irregularity, and stress state on the uniaxial creep are explored. By taking the mass at strut nodes into account, the creep foam model by Gibson and Ashby (Cellular Solids: Structure and Properties, 2nd ed., Cambridge University Press, Cambridge, UK, 1997) is modified. Obtained results show that the uniaxial secondary foam creep rate predicted by the FE simulations can be well captured by the modified creep model. For multiaxial secondary creep, a phenomenological elastoplastic constitutive model is extended to include the rate effect into the creep response of 3D Voronoi foams. Again, the model predictions agree well with the FE results.