INFLUENCE OF THE HIGHER ORDER TERMS IN WILLIAMS' SERIES EXPANSION OF THE STRESS FIELD ON THE STRESS-STRAIN STATE IN THE VICINITY OF THE CRACK TIP. PART I
The paper is devoted to the multi-parameter description of the stress fields in the vicinity of two collinear crack of different length in an infinite isotropic elastic medium subjected to 1) Mode I loading; 2) Mode II loading; 3) mixed (Mode I + Mode II) mode loading. The multi-parameter asymptotic expansions of the stress field in the vicinity of the crack tip in isotropic linear elastic media under mixed mode loading are obtained. The amplitude coefficients of the multi-parameter series expansion are found in the closed form. Having obtained the coefficients of the Williams series expansion one can keep any preassigned number of terms in the asymptotic series. Asymptotic analysis of number of the terms in the Williams asymptotic series which is necessary to keep in the asymptotic series at different distances from the crack tip. It is shown that the more distance from the crack tip the more terms in the Williams asymptotic expansion need to be kept.