A notch root radius to attain minimum fracture loads in plates weakened by U-notches under Mode I loading

作者：Barati E^*; Alizadeh Y

来源：Scientia Iranica, 2012, 19(3): 491-502.

DOI：10.1016/j.scient.2012.04.010

• U-notch
• Fracture load
• Mode I loading
• Failure criteria

The paper deals with the minimum value of a fracture load, with respect to the notch root radius, in plates weakened by U-notches under Mode I loading. It has been found that the fracture load has a minimum value at a critical value of the notch root radius (rho), using four criteria, namely, Mean Stress (MS), maximum tangent stress or Point Stress (PS), Critical Strain-Energy (CSE) and Averaged Strain-Energy Density (ASED). Using a characteristic length (l(ch)), which is a function of material properties, the results showed that the dimensionless critical notch root radius (rho/l(ch))(cr) depended on w/a ratio (the specimen width to the notch depth), Poisson ratio, and loading condition (tensile or bending loading) under Mode I loading. In other words, according to these criteria, a notch root radius different from zero exists, providing a minimum fracture load. Therefore, a crack is not more dangerous rather than a U-notch under Mode I loading. This critical notch root radius is important for a quasi-brittle material, but may not be significant for brittle ones in practical engineering situations. Good agreement was found between theoretical predictions and experimental results on A1356-T6.

• 出版日期2012-6