Investigate the impact of the probability of rupture on the Weibull parameters of gray cast iron through calculated expressions

This research focuses on the tensile behavior of gray cast iron samples containing a high percentage of carbon with spheroidal graphite, specifically for EN-GJS-500-7 key rings. An empirical model is applied to address various issues, and in the case of our gray cast iron with a high carbon content and spheroidal graphite, each link represents a volume element. The weakest links correspond to the volume elements that contain the most critical defects. Through experimental testing, the specimens were subjected to rupture, resulting in different rupture stresses, denoted as σ1 and σ6. These rupture stresses are associated with a probability level of rupture based on their rank, denoted as i. To calculate the probability of rupture, three analytic expressions are utilized: Pr = i / (N + 1), Pr = (i-0.3) / (i + 0.4), and Pr = (i-O.S) / N. These expressions allow for the estimation of the probability of rupture for each rank i. The fragility of the material's failure is evident from the low measured values of the Weibull modulus. Furthermore, an analysis of the load-displacement curves enables the quantification of the material's resistance to crack propagation. By examining these curves, the main mechanisms governing the failure of the material can be preliminarily investigated.