When dealing with bending stress in structural engineering, what is the typical relation to yield stress?

In structural engineering, the relationship between bending stress and yield stress is crucial for ensuring that materials behave safely and predictably under load. The correct choice indicates that bending stress is typically around 65% of the yield stress. This alignment is informed by design principles that prioritize safety and serviceability, particularly in the context of materials like steel.

Using yield stress as a benchmark helps engineers avoid scenarios where materials yield or deform plastically under normal operating conditions. The 65% factor reflects common practices where a safety margin is allowed, ensuring that the structure operates within elastic limits. This level allows some degree of reserve strength, which can be vital for addressing unexpected loads or stresses that may occur throughout the lifespan of a structure, such as dynamic loads, environmental effects, or aging.

A design that limits bending stress to approximately 65% of yield stress also serves to manage fatigue and reduce the likelihood of structural failure. In practice, many engineering codes and standards, including those for concrete and steel structures, may advocate for maintaining stresses well below yield limits to enhance the longevity and reliability of the materials used.

In contrast, options suggesting 100%, 50%, or 75% of yield stress do not align with typical safety practices in structural design. A maximum bending stress