Calibration method for the brittle fracture assessment parameters for materials based on the beremin model

A calibration method for the brittle fracture assessment parameters for materials based on the Beremin model, characterized in that, the method comprises the following steps:

• (1) Selecting at least two types of specimens made of a same material but with different constraints, and calculating the fracture toughness value K0 corresponding to 63.2% failure probability for each type of specimens at a same calibration temperature by using the respective fracture toughness data;
• (2) Constructing finite element models for each type of specimens using the stress-strain curve of the material measured at the same calibration temperature, and calculating the maximum principal stress σl,i and element volume Vi of each element at K=K0 in each model, where K is a stress intensity factor that describes the intensity of far field loading on the crack front, and i is an order number of elements;
• (3) Assuming a series of values of the Weibull slope m and calculating a set of values of the Weibull scale parameter σu for each type of specimens according to the following equation, and plotting the Beremin's parameters characteristic curves for each type of specimens, i.e. the curves representing the relationship between m and σu for each type of specimens;
• σ
• u
• =
• ∑
• i
• n
• 
• (
• σ
• 1
• ,
• i
• )
• m
• 
• V
• i
• V
• 0
• m
• wherein, n represents the number of elements in the fracture process region, V0 represents a reference volume;
• (4) Determining the brittle fracture assessment parameters for the material according to the coordinates of the intersection of the Beremin's parameters characteristic curves.