Which mechanism caused repeated failures in early iron suspension bridges during the 19th century?

💡 Explanation

When early iron suspension bridges experienced cyclic loading, fatigue crack growth occurred because repeated stress weakened the iron's microscopic structure, leading to eventual fracture. Therefore fatigue crack growth results, rather than corrosion or erosion, which require electrochemical or chemical breakdown.

• Which hydrological consequence during Aztec chinampa construction could result in salinization of the soil?
• Which navigational challenge increased when 18th-century ships experienced sustained voyages at high latitudes?
• Which risk increased within settlements as ancient Mesopotamian canal systems aged and deteriorated without maintenance?
• Which long-term consequence results from repeated intensive terrace cultivation without adequate soil replenishment in Andean highlands?
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• Which risk increases when a 18th-century navigator sights the sun using a sextant with a warped index mirror?