Criteria for Yielding or Failure of Cellular Materials

Abstract

Sandwich structures are used extensively in marine structures and other applications. Cellular materials such as foams, honeycomb, and balsa wood used as core materials in sandwich structures are subjected to multiaxial loadings. Concentrated loads, impacts, and explosions can result in large deformations and damage, and yield or failure criteria are needed to predict the end of the elastic phase. Yielding or failure of isotropic foams is generally dependent on the hydrostatic stress, a feature that these materials share with many polymers, concrete, and soils. Appropriate criteria which are different from those traditionally used for metals have been classified in four major categories. Similarities between seemingly different criteria and between foams and other materials are brought out. Foams can also be anisotropic as honeycomb and balsa wood, and the anisotropy has to be accounted for in addition to the differences in strength in tension and compression in various directions. Suitable anisotropic criteria are shown to be the extensions of criteria previously used for isotropic materials and methods to present these criteria in a unified manner or to systematically extend isotropic criteria are discussed. Finally the strain rate effects and size effects are discussed.

Mechanical properties of multifunctional foam core materials

“…Daniel et al [20] have discussed the initiation of different failure modes in PVC foam core sandwich structures and correlated the findings to foam density, material properties, and loading conditions. [19,[21][22][23][24][25][26]. [19,[21][22][23][24][25][26].…”

Characterization of Anisotropic Polymeric Foam Under Static and Dynamic Loading

“…Gdoutos et al [6] and Deshpande et al [7] discussed multi-axial characterization of foams including failure criteria. Additional quasi-static characterization studies including yield and failure criteria have been discussed by Fiedler et al [8], Abrate [9], and FloresJohnson and Li [10]. Kanny et al [11] and Zenkert et al [12] characterized polymeric foams under static and cyclic loading and studied the failure mechanisms.…”

“…Polymeric foams are usually made of polyvinyl chloride (PVC), polyurethane (PUR) or polystyrene. The mechanical behavior of cellular foams has been investigated and discussed extensively in the literature over the last two decades [3][4][5][6][7][8][9][10][11][12][13][14][15]. In most cases the emphasis is on the energy absorption characteristics of foams undergoing large dynamic deformations.…”

Computational plasticity model for hydrostatic pressure dependent foam materials

“…The progression of failure criteria about cellular materials have been described and summarized to four categories by Abrate. 5 The failure criteria that take into account of the different behaviors in compression and tension are commonly used for concrete and soils. The most well-known has been the Mohr-Coulomb criterion, which represents the linear envelope that is obtained from a plot of the shear strength of a material versus the applied normal stress.…”