Evaluating Method Of The Fracture Toughness Using Instrumented indentation testing

摘要

The present invention relates to a method to measure fracture toughness using a continuous indentation test method, and to a method to measure fracture toughness by using the continuous indentation test method to measure a load and the indentation depth in real time while applying the load to a specimen by a flat punch-shaped indenter. According to the present invention, the method comprises: an indentation test performance step of performing an indentation test up to a predetermined indentation depth with an indenter with a predetermined radius to generate a set load displacement curve; a conversion step of converting the set load displacement curve into a generalized curve of the radius of the indenter with respect to the load and the indentation depth; a step of searching for a fracture start stress of a time point when the fracture has started and the radius of the indenter with respect to the indentation depth at the fracture start time point in a generalized curve; a step of calculating the fracture start stress, the radius with respect to the indentation depth at the fracture start time point, and the radius or indentation depth of the set indenter to calculate an adjusted radius of the indenter; and a load displacement curve generation step of generating a load displacement curve adjusted in accordance with the indenter with the adjusted radius.