The line spring solutions used to solve part-through crack problems in
plates are investigated by comparing with the results obtained from a
n accurate three-dimensional analysis using the body force method. Com
parisons are made for the mode I stress intensity of a semi-elliptical
crack with various aspect ratios a/b, i.e. the ratio of the width to
the depth of the crack. The results indicate that the two methods agre
e well for cracks that are wider than they are deep (an aspect ratio g
reater than one).