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This paper aims to adopt experiments and numerical analysis on double-edged through cracks in metallic plates, to explore the stress intensity factor (SIF''s) with various crack lengths and different inclined angles due to the tension tests. And we also find the finite size correction factor a function of the ratio of crack length versus specimen''s width.
The experiments contain two parts: one is symmetrically doubleedged inclined cracks, the other is anti-symmetrically double-edged inclined cracks. The specimen dimensions, crack length, and width are made according to the standards of American Society for Testing and Materials(ASTM). The inclined angle of each specimen has an increment of 15°, and the range of inclined angles is from 0° which is perpendicular to the direction of applied load to 75°. Then do the tests with a universal material testing machine MTS. The computerized tests and photograph equipment can record the data of load, displacement, strain and crack length at the identical time, then using the technology of Belt Came to observe crack length and calculate SIF''s thereafter. The fracture mode can be regarded as a mixed mode of Mode Ⅰand ModeⅡ.
On the aspect of numerical analysis, we employ the softwares of PATRAN and ABAQUS to obtain the exact stresses under the situation of crack tip, adopting the quarter-point crack tip singular elements to model the element, because of the singularity of 1/√r. The contents contains three parts: the first part is symmetrical double-edged inclined cracks, antisymmetrical double-edged inclined cracks, and non-symmetrical doubleedged inclined cracks.
KⅠis decreased with the increase of inclined angle, the value of KⅡ is maximal when the inclined angle is 45°. And KⅠis larger than KⅡthat shows that KⅠis the dominating fracture mode. No matter what of the symmetrical cracks or anti-symmetrical cracks, the data from experiments are correlated well with numerical analysis in comparison.
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