Lightweight Potential of Novel Cellular Spherical Composites

Abstract

The elastic properties of cellular solids are determined with regard to the structural construction. The relative density is mostly applied to describe the material parameters in the elastic range. Öchsner et al. [1] investigated perforated metal sheets as idealised model material for cellular solids. He demonstrated that the mechanical properties of cellular solids decrease superproportional with decreasing relative density. He showed that phenomenon not only for real cellular solids but also for the idealised model materials. Therefore optimisation of the production process for cellular solids with perfect structures does not yield in optimal elastic properties automatically.The cellular spherical composites could improve the mechanical properties compared to conventional cellular solids. This composites are syntactical foams. The spherical place holders which are disposed for the production of the syntactical foam affects the mechanical properties of the cellular basic material positive. The lightweight potential of cellular spherical composites in the elastic range is investigated in the following contribution. It is shown that the mechanical properties of cellular spherical composites can be better compared to conventional cellular solids with equal weight. The composite ªmineral foam granulates in polyamide matrixº is used as example for a cellular spherical composite.Procedure: It is to be investigated if a cellular spherical composite shows better mechanical properties than conventional cellular solids with respect to its weight. For that purpose the mechanical properties of the composite are tested experimentally. The cellular spherical composite under investigation can be produced only with approximately 43 % volume fraction polyamide and 57 % volume fraction mineral foam granulate at time. Therefore the cellular composite can not be tested experimentally with different relative densities. Thus the cellular spherical composite is simulated numerical with a FEM meso model. The applicability of the FEM meso model is investigated by a comparison between experiment and simulation.The cellular composite and the pure polyamide foam are simulated with a FEM meso model for different relative densities. The graph of the stiffness against the relative density is characterised by a rheological analogous model to develop a better understanding for the mechanical behaviour of a cellular composite. The results will be verified

Lightweight Potential of Anisotropic Plate Lattice Metamaterials

“…It is clearly recognizable that all three unit cells show a maximum value of the modulus of elasticity in the z-direction. These maximum values coincide, with a deviation smaller than 1%, to the values determined through the Voigt bound [61], which was applied for cellular materials by [62] and provides the effective modulus of elasticity for the parallel connection of two isotropic linear elastic materials, which are, in the present case, AlSi10Mg and a gas. This confirms that the elastic material properties of the lattice structures can be accurately captured using volume elements.…”

Mechanical behavior of a cellular composite under quasi-static, static, and cyclic compression loading

“…Details of the homogenization procedure are presented in [27]. Commonly used body-centered or face-centered cubic cell models for syntactic foams, see, e.g., [12], assume a periodical microstructure of the material. Cellular composites with glass foam granules and polymer matrix, however, show isotropic material behavior as was proven experimentally in [24].…”

“…Metals or polymers can be used as matrix material combined with place holders consisting of glass, mineral, or metal foams [12,13]. The mechanical properties of cellular composites such as strength or stiffness can be improved compared to conventional cellular solids with equal weight using cellular place holders [12].…”

A Continuum Damage Mechanics Model for the Static and Cyclic Fatigue of Cellular Composites

“…Cellular composites are composite foams with cellular granules as place holders in a polymer or metal matrix material. The place holders consist of glass, mineral, or metal closed-cell foams [ 1 , 2 ]. When using appropriate material combinations for the matrix and place holders, the cellular place holders improve the weight-specific mechanical properties of the cellular composite.…”

“…The investigated cellular composite consists of cellular glass granules from recycled glass embedded in an epoxy matrix. The material offers high weight-specific stiffness and compressive strength at low material costs [ 1 , 3 , 4 ]. Cellular composites are manufactured by the infiltration of granules with the matrix material via a casting process [ 5 ].…”