Evaluation of the Damage Value of Steel Alloys Using a CDM Model

Damage is a phenomenon experienced when a material is subjected to external factors such as load and temperature. Damage is quantified through the damage value of a material, and its value typically ranges from 0 to 1, with 1 indicating complete damage. The damage value in this context primarily refers to the crack initiation condition, indicating failure. The damage value corresponding to this condition is referred to as critical damage. However, most materials tend to fail at a critical damage value of less than one. Researchers have developed different models to evaluate damage, and some of the prominent models are Lemaitre, Rice & Tracy, Gurson, and Bhattacharya & Ellingwood. This study uses the Bhattacharya & Ellingwood model to evaluate the damage value of 113 selected steel materials that play crucial roles in aerospace, automobile, and other industrial applications. This model uses monotonic properties of the material as the input and estimates the critical damage value (D_c). The study revealed that, for steel materials, the D_c value generally ranges from 0.1 to 0.7. This study highlights the variation in damage with plastic strain under monotonic loading, and this helps to quickly select a specific material when the damage criterion is crack initiation.