When a natural frequency is excited by a forcing frequency, what condition could lead to damage?

Resonance occurs when a system is subjected to a forcing frequency that matches one of its natural frequencies. This alignment can result in amplified vibrations, causing significant increases in motion and energy within the system. If these vibrations reach a certain threshold, they can lead to structural failure or damage due to the excessive stresses imposed on materials and components.

In vibration analysis, recognizing the potential for resonance is crucial; engineers must design systems to avoid operating within this resonant frequency zone, especially during operational changes or sudden impacts. Understanding resonance is key to ensuring the longevity and safety of mechanical systems.

Other factors like critical speed, shock loading, and general vibration can introduce stress, but they do not necessarily involve the specific mechanism of energy amplification that characterizes resonance. Critical speed pertains to rotational dynamics, while shock loading relates to sudden impacts rather than continuous oscillation. Therefore, while all options represent scenarios that can impact a system’s integrity, it is the resonance condition that is specifically notorious for leading to catastrophic damage when excited at the right frequency.