title: A two-scale Weibull approach to the failure of porous ceramic structures made by robocasting: possibilities and limits.
abstract: This paper introduces our approach to modeling the mechanical behavior of cellular ceramics, through the example of calcium phosphate scaffolds made by robocasting for bone-tissue engineering. The Weibull theory is used to deal with the scaffolds' constitutive rods statistical failure, and the Sanchez-Palencia theory of periodic homogenization is used to link the rod- and scaffold-scales. Uniaxial compression of scaffolds and three-point bending of rods were performed to calibrate and validate the model. If calibration based on rod-scale data leads to over-conservative predictions of scaffold's properties (as rods' successive failures are not taken into account), we show that, for a given rod diameter, calibration based on scaffold-scale data leads to very satisfactory predictions for a wide range of rod spacing, i.e. of scaffold porosity, as well as for different loading conditions. This work establishes the proposed model as a reliable tool for understanding and optimizing cellular ceramics' mechanical properties.
authors: Materials Science Division, Lawrence Berkeley National Laboratory, California, USA.
authors: Martin
authors: M
authors: Genet
authors: Manuel
authors: M
authors: Houmard
authors: Salvador
authors: S
authors: Eslava
authors: Eduardo
authors: E
authors: Saiz
authors: Antoni P
authors: AP
authors: Tomsia
keywords: Biomedical applications; Cellular ceramics; Fracture; Mechanical properties; Strength