What is the term for story drift divided by the story height in structural analysis?

The term for story drift divided by the story height in structural analysis is known as the story drift ratio. This ratio is significant in assessing the lateral stability of a structure under loading conditions, such as seismic or wind forces. The story drift ratio provides insight into how much a particular level of a building moves relative to the total height of that story, which helps engineers evaluate the performance of a structure in terms of its flexibility and its ability to withstand lateral loads without sustaining damage.

Measuring the story drift in relation to the height allows for a standardized comparison across different structures or building designs. This ratio is crucial for ensuring that a building meets the necessary performance criteria and safety standards, particularly in areas prone to seismic activity.

The other terms do not directly relate to the specific concept of story drift divided by story height. Deflection ratio generally refers to the overall deflection experienced by a member compared to its span. Lateral displacement ratio might refer to a broader context of displacement but does not specifically define the ratio of story drift to height. Amplification ratio is related to factors that increase loading effects but does not pertain directly to story drift analysis.