Glass transition and instant freezing theories - Α comparison of frozen-in temper stresses

For many practical cases of tempering the temper stresses calculated by instant freezing theories are sufficient and in good agreement with experiments. The auhors give a brief summary of the theories by Adams and Williamson, Bartenev and Indenbom and discuss their numerical Implementation. For example, frozen-in temper stresses are calculated and discussed within the model of a symmetrically cooled, infinite glass plate. Based on the numerical soludon of the heat conduction equadon with a given heat transfer coefficient, especially the influence of the inidal temperature of quenching is investigated. Furthermore, a numerical algorithm is presented to calculate the temporal evoludon of the permanent temper stresses for Indenbom's theory. Finally, as a practical example, residual stresses are determined in the surface of a tempered glass-particle composite system