The failure of engineering materials and structures may have detrimental effects on safety and costs. Maintaining the integrity of structures throughout their lifetime plays a key role for safety in many areas where a structural failure would entail health hazards or losses of life. Evident examples are nuclear reactors, chemical industries, transport, buildings, bridges, and off-shore platforms. Structural failure may be aggravated by the use of structures under traffic and loading conditions which were not originally taken into account in the design specifications.
Studies performed in the USA and in other countries have shown that the cost of the three main processes that durable materials must withstand, [ie] fracture, corrosion, and erosion and wear is probably about 10% of the Gross National Product in industrial countries. Fracture was estimated to cost about $120 billion (1982 dollars) per year in the USA and corrosion at least as much. In the USA more than 400,000 highway bridges were built prior to 1935, and many therefore no longer adequately or safely serve current traffic demands. In Mexico City subsidence in the District Federale has caused a very considerable amount of structural failure.