Numerical and experimental study on the thermal shock strength of tungsten by laser irradiation

The purpose of this paper is to investigate the thermal shock property of Tungsten through finite element method and laser irradiation experiments. A finite element model is developed to simulate the thermal shock behavior of Tungsten irradiated by a laser beam. An axis-symmetric model is adopted to perform the numerical simulation with the finite element code ABAQUS. The element removal and reactivation methods are used to simulate the melting and solidification processes, where the latent heat of Tungsten is introduced to consider the additional heat due to phase change. Distributions of the radial and circumferential stresses are discussed in detail. In addition, a three dimensional finite element model is also developed to calculate the value of K-I. Variations of K-I at the tip points of a radial crack with time in the cooling process are obtained. The critical power density curves are presented by taking the tensile strength criterion. Finally the thermal shock experiments are performed. Good agreements between the numerical solutions and the experimental results are achieved. It is concluded that the critical power density curves can be a measure to evaluate the thermal shock strength of Tungsten. (c) 2007 Elsevier B.V. All rights reserved.