Development of a temperature dependent, non-linear cohesive zone model for laser induced fracture.

摘要

Within recent times there has been much interest generated in the area of high powered lasers and their interaction with materials. As a result, lasers are very well characterized for their industrial applications. However, when materials are subjected to intense levels of laser radiation beyond the range for controlled processing operations, complicated physical and mechanical phenomenon such as melting, vaporization, and electro-dissociation can occur. Failure prediction under such extreme loading conditions becomes an increasingly difficult task due to the rapid deposition of energy that occurs within the heat affected zone.; A cohesive zone model is developed to simulate the effects of laser irradiation on aluminum specimens that are simultaneously subjected to displacement controlled loading. However, the current interface cohesive element formulation is only applicable under isothermal conditions. In order to make these elements temperature dependent, a technique is developed in this study that allows the key parameters used in the constitutive model for defining the response of these cohesive elements, to be calibrated for the thermal field induced by a high powered CO2 laser.