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In this paper, the application requirement of the Residual Property Model based on the decrescent exponential function is reduced to only one mechanical test datum. For this, by using Creager and Paris's elastic stress field equation in front of the blunt elliptical hole, the theoretical radius was chosen for the tip curvative and the maximum stress in the load direction at the tip is ensured to be equal the fracture toughness. Thus, the workload of the model is reduced by making the u exponent in the e-u function dependent on the geometric correction factor and the crack length. It was applied to the laminated composite specimens with three-point bending and the specimens including circular hole, and critical fracture stress values close to actual values were achieved. [ABSTRACT FROM AUTHOR]

In this paper, the energy release energy corresponding to the unit crack propagation obtained from the displacement-controlled load-displacement plot is equalized to the elastic energy release rate, and the variation of stiffness based on the crack length is obtained. For this purpose, instead of measuring the amount of crack mouth opening in the single edge-cracked tensile specimen, the extensometer elongation amount was taken in the middle part of the specimen. Thanks to the equality of the stiffness to the crack length, the transformation of the load-displacement curve into the material resistance curve was realized. [ABSTRACT FROM AUTHOR]