Influence of Boundary Conditions on Dynamic Characterization of Launch Vehicle Structures with Closely Spaced Modes

<div class="section abstract"><div class="htmlview paragraph">Dynamic characterization tests play a critical role in launch vehicle applications, as they provide the frequencies and mode shapes required for refining Finite Element Models (FEM) and ensuring structural integrity. While such tests are often routine when mode shapes in orthogonal planes are well separated, practical challenges arise when modes are closely spaced. In these cases, careful test planning and execution become