No abstract

No abstract

No abstract

No abstract

The stress intensity factor of a 且11ite specimen with anunsymmetr ［ cal crack initiated from a h〔｝1e due to tension was calculated ． The geometric stress intensity factor of this specimen with the cracked hole was compared with that 〔 〕 f a center cracked p 】 ate ， whose length wus equal to the sum of the diameter of the hole and length of the crack ． R ． was defined as the ratio of these geometric factors ， where thc nondimensional diameter of the hole a1W is less than O． 2and RF is】 ess than l． 1 after the crack grow し h length c ！ LV reaches O． 1．2a， 2( ・ ， and 2 W are the diameter of the hole， 1ength of the crack from the edge of the hole ， and width of the piate ， respectively ． Therefore， the stress intensity factor of a plate with cracks initiated frorn holes on its surface can be approxirnated within 10％ error by the stress intensity of a center cracked plate when af ； V is less than O ． 2 ， though cracks initiated from edges are unsymmetrical ． When a ／ LV is larger than O ． 3 ， RF becomes larger than 1 ． 1 across a wide range of c1 罪 ． Further， the stress intensity factor of a finite plate with an unsymmetri ・ cal crack was calculated ． Under the calculation conditions employed in the present study ， thc stress intensity factor of the plate with the unsymmetrical crack could also be approximated within 10 ％ error by that of the center cracked plate 、