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8 Fracture Mechanics: Fundamentals and Applications
FIGURE 1.5 Kings College Chapel in Cambridge, England. This structure was completed in 1515.
The cause of the failure of the molasses tank was largely a mystery at the time. In the first
edition of his elasticity text published in 1892, Love [6] remarked that “the conditions of rupture
are but vaguely understood.” Designers typically applied safety factors of 10 or more (based on
the tensile strength) in an effort to avoid these seemingly random failures.
1.2.1 EARLY FRACTURE RESEARCH
Experiments performed by Leonardo da Vinci several centuries earlier provided some clues as to
the root cause of fracture. He measured the strength of iron wires and found that the strength varied
inversely with wire length. These results implied that flaws in the material controlled the strength;
FIGURE 1.6 The Tower Bridge in London, completed in 1894. Note the modern beam design, made possible
by the availability of steel support girders.
