Impact of Density Gradients on the Stress Level Within a Green Ceramic Compact During Drying

Abstract:

Internal water content and mechanical stress distributions during convective drying were simulated for a homogeneous and a heterogeneous (with density gradients) annular compact of a green ceramic agglomerate. A diffusive model for water transfer and an elastic model for structural mechanics were applied. Based on experimental measurements, the material apparent density was numerically implemented as a function of spatial coordinates and the key material properties (moisture diffusivity and the Young's modulus) were implemented as functions of material density. The heterogeneous compact (with density peaks at the top edges) exhibited three times larger circumferential tensile stress at the top external radius corner than that exhibited by the homogeneous one.

Keywords:

• Apparent density
• Ceramic
• Cracks
• Structural mechanics
• Water transfer

ACKNOWLEDGMENTS

This work was financially supported by two French governmental agencies: Agence pour le Développement et la Maîtrise de l'Energie (ADEME) and Agence Nationale de la Recherche Technique (ANRT).