Simulating the cyclic mechanical response of titanium alloy 834 at 630°C

Abstract

This paper explores features of observed material response under cyclic loading of a creep resistant titanium alloy, IMI 834. Methods of describing the material response are examined, particularly in the context of material models available in the ABAQUS finite element (FE) code. Isotropic, kinematic and combined hardening models are used to describe material behaviour under cyclic loading. Results from an earlier test programme are examined in detail, and the results are used to identify material constants. The models are implemented external to the FE code, and used to simulate the material response. Results from simulations are then compared with experimental results. It is found that the current ABAQUS models are not sufficiently detailed to provide an accurate representation of material behaviour, and additional parameters are required. The simulations overestimate the decrease the peak stress as a function of the number of cycles and underestimate the cyclic plastic strain range.

Keywords:

• cyclic loading
• material models
• low cycle fatigue