Analysis of Compressive Damage Behaviour of Tungsten Heavy Alloy

Abstract This study reports the ductile damage response of Tungsten Heavy Alloy (THA), subjected to uniaxial compression tests at a low strain rate of 1s −1 and a temperature of 323K on the Gleeble 3800 thermo-mechanical simulator. Initially, the smooth cylindrical specimen and two notched specimens with notch radius of R 1.5 mm and R 2mm, were prepared for the compression test. Experimentation showed the barreling effect in smooth specimen without fracture, while an early fracture is reported for the R 1.5mm notched specimen with a fracture strain of 0.124. However, a delay in fracture is seen for the R 2mm notched specimen at a fracture strain of 0.146. The Johnson and Cook (JC) damage model is introduced to predict the damage behaviour of THA. A robust finite element (FE) model for smooth and notched specimens is developed, and simulations were carried out in ABAQUS/CAE software. The FE simulated load-displacement curves for all specimens are validated against the experimental load-displacement curves. A slight crack can be observed in the FE simulated models for both notched specimens at the notch root, with an early fracture observed in the simulation compared to the fracture that actually occurred after experimentation. A negative stress triaxiality is observed for both notched specimens at the critical region of fracture, with R 2mm specimen reported high triaxiality compared to R 1.5mm specimen. The transition in Lode angle parameter for R1.5mm, from negative to positive, shifts the stress state from axisymmetric compression towards axisymmetric tension. In contrast, a negative Lode parameter is found for the R2mm specimen, maintaining a purely axisymmetric compression stress state.