Estimation of stress field for sharp V-notch in power-law creeping solids: An asymptotic viewpoint

The characterization of the stress field for notch contained structures and components at elevated temperature is a preliminary to assess their safety and integrity reasonably. In this paper, the characteristics of the sharp V-notch tip field in power-law creeping materials are presented from the asymptotic viewpoint. Through asymptotic analysis and solution, the stress exponents and the angular distribution functions for various notch angles and creep exponents are presented. The asymptotic structure of the stress field for the sharp V-notch tip field is presented by proposing the amplitude factor K(t) which is dependent on the creep time, specimen geometry, notch angle as well as loading condition. The amplitude factor K(t) can bridge the fracture parameters between notch and crack in power-law creeping solids. A reasonable and accurate estimation method for the evaluation of the K(t) factor is also proposed. With the determination of K(t), the notch tip stress fields of single edged sharp V-notch specimens in power-law creeping materials with various notch angles and different depths are presented, compared and analyzed. It has been verified that the stress components for sharp V-notch specimens can be estimated accurately and reasonably with the theory and method proposed in this paper. The differences of the asymptotic solutions for sharp V-notch tip in power-law creeping solids and power-law hardening materials are also discussed and clarified. (C) 2019 Elsevier Ltd. All rights reserved.