Young’s modulus evolution with temperature of glass/andalusite model materials: Experimental and numerical approach
Résumé
An experimental and numerical study devoted to the elastic behavior of a two-phase material is investigated in this work. Samples have been elaborated by incorporating andalusite inclusions with anisotropic mechanical and thermal properties in a vitreous matrix. SEM observations show large unexpected fractures located inside inclusions despite the significant thermal expansion mismatch between the two components, normally leading to interfacial decohesions or multicracking of the matrix. These fractures are explained by a strong interfacial reactivity coupled to the weak stress to rupture of individual andalusite aggregates during the processing thermal cycle affected by a preexisting anisotropic damage. Young’s modulus vs. temperature was both measured by ultrasonic technique and calculated by a numerical simulation. The investigated models take into account individual anisotropic thermo-elastic properties of the dispersed phase. Numerical results show a modification of the stress distribution field depending on anisotropic properties of the dispersed phase, their arrangement and interactions. Increasing the number of inclusions and optimizing their shape and spatial distribution cancels the effect of anisotropy. Finally, the numerical values of Young’s modulus are in good tendency with experimental results vs. temperature.