In vibration analysis, what is resonance?

Resonance in vibration analysis occurs when the frequency of an external force applied to a system matches the system’s natural frequency. This matching condition leads to a significant increase in amplitude of the system's vibrations. Essentially, since every system has natural frequencies at which it tends to vibrate, introducing an external force that resonates with these frequencies can lead to excessive vibrations, potentially causing damage or failure.

Understanding resonance is crucial for engineers and technicians as it can inform them on how to design systems in such a way that they avoid exciting these natural frequencies. This concept plays a vital role in many applications, from machinery and structural dynamics to any situation involving oscillatory systems.

The other choices touch on different aspects of vibration analysis but do not capture the essence of resonance. For instance, a consistent vibration pattern indicates normal function rather than the specific dynamics of resonance. Measurement of vibration over frequency refers to various analytical techniques but does not define resonance itself. Similarly, a type of irregular pulse in machines describes a different phenomenon that falls outside the resonance concept.