Page 24 - T. Anderson-Fracture Mechanics - Fundamentals and Applns.-CRC (2005)

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4 Fracture Mechanics: Fundamentals and Applications

(a)

(b)

FIGURE 1.1 The MSV Kurdistan oil tanker, which sustained a brittle fracture while sailing in the North
Atlantic in 1979: (a) fractured vessel in dry dock and (b) bilge keel from which the fracture initiated.
(Photographs provided by S.J. Garwood.)

while sailing in the North Atlantic [2]. The combination of warm oil in the tanker with cold water
in contact with the outer hull produced substantial thermal stresses. The fracture initiated from a
bilge keel that was improperly welded. The weld failed to penetrate the structural detail, resulting
in a severe stress concentration. Although the hull steel had adequate toughness to prevent fracture
initiation, it failed to stop the propagating crack.
Polymers, which are becoming more common in structural applications, provide a number of
advantages over metals, but also have the potential for causing Type 2 failures. For example,