Component fracture evaluation device, component fracture evaluation method and computer program

A component fracture evaluation device evaluating fracture performance of a machine component, comprising:

• a computer processor;
• and
• a memory storing a program of instructions for:
• a threshold value excess number of inclusions deriving unit deriving a threshold value excess number of inclusions, the threshold value excess number of inclusions being the number of inclusions whose inclusion size exceeds a threshold value among the inclusions contained in a sample based on the inclusion size being a size of the inclusion extracted from the sample made up of the same kind of material as a material constituting the machine component;
• a coefficient deriving unit deriving coefficients of a generalized Pareto distribution based on the inclusion size of the extracted inclusion, the threshold value excess number of inclusions, and the threshold value on an assumption that a distribution function of the inclusion size of the extracted inclusion follows the generalized Pareto distribution;
• a virtual inclusion ratio deriving unit deriving a virtual inclusion ratio being a ratio between the threshold value excess number of inclusions being the number of inclusions whose inclusion size exceeds the threshold value among the inclusions contained in the sample and a zero excess number of inclusions being the number of inclusions whose inclusion size exceeds “0” (zero) among the inclusions contained in the sample;
• and
• a virtual unit volume deriving unit deriving a virtual unit volume being a volume of a virtual cell when the machine component is equally divided by plural virtual cells each containing one inclusion based on the threshold value excess number of inclusions, the virtual inclusion ratio, and a volume of the sample,
• wherein an index evaluating the fracture performance of the machine component by a unit of the virtual cell having the virtual unit volume derived by the virtual unit volume deriving unit is derived, and the fracture performance of the machine component is evaluated by using the derived index.

A non-transitory computer readable medium storing a program of instructions for causing a computer to execute an evaluation of fracture performance of a machine component, the computer program causing the computer to execute:

• a threshold value excess number of inclusions deriving process deriving a threshold value excess number of inclusions being the number of inclusions whose inclusion size exceeds a threshold value among the inclusions contained in a sample based on the inclusion size being a size of the inclusion extracted from the sample made up of the same kind of material as a material constituting the machine component;
• a coefficient deriving process deriving coefficients of a generalized Pareto distribution based on the inclusion size of the extracted inclusion, the threshold value excess number of inclusions, and the threshold value on an assumption that a distribution function of the inclusion size of the extracted inclusion follows the generalized Pareto distribution;
• a virtual inclusion ratio deriving process deriving a virtual inclusion ratio being a ratio between the threshold value excess number of inclusions being the number of inclusions whose inclusion size exceeds the threshold value among the inclusions contained in the sample and a zero excess number of inclusions being the number of inclusions whose inclusion size exceeds “0” (zero) among the inclusions contained in the sample;
• and
• a virtual unit volume deriving process deriving a virtual unit volume being a volume of a virtual cell when the machine component is equally divided by plural virtual cells each containing one inclusion based on the threshold value excess number of inclusions, the virtual inclusion ratio, and a volume of the sample,
• wherein an index evaluating the fracture performance of the machine component by a unit of the virtual cell having the virtual unit volume derived by the virtual unit volume deriving process is derived, and the fracture performance of the machine component is evaluated by using the derived index.