Which option is NOT listed as contributing to brittle failure?

• A. Elevated ductility
• B. Cold temperatures
• C. High load rates
• D. Rigid constraints

Answer: (A)

Brittle failure happens when a material can’t deform plastically enough before it breaks, so toughness and the ability to absorb energy are key defenses against it. Cold temperatures lower toughness, making steel and other bridge materials more prone to sudden fracture. High loading rates leave little time for plastic deformation, pushing the material toward brittle behavior. Rigid constraints raise stress concentrations and restrict deformation, which can localize and promote brittle-type cracks. Elevated ductility, on the other hand, increases the material’s ability to deform and absorb energy before fracturing, so it does not contribute to brittle failure. That’s why elevated ductility is the option that does not belong among the factors that promote brittle failure.