b'Engineer Innovation | Aerospace & DefenseModal testing made easy Figure 1: Large scale modal test with the new MLMM techniqueModal testing is a very useful techniqueHowever, efficiently conducting a modal for verifying and understanding thetest can be a difficult task. When dynamic behavior of complex structures.processing measurement data to extract Its principle is to characterize a structuremodal parameters, several choices must by its resonant modes with associatedbe made by the engineer, making it resonant frequencies, damping anddifficult to get reliable and consistent mode shapes, which help identifydata. For instance, in the case of highly potential issues or weaknesses in thedamped structures or large structures design.instrumented with hundreds of sensors with high modal density, properly This technique has been widely used forchoosing the poles of the modal model decades on various types of structures;is challengingit is not always from small components to fullystraightforward and might require deep integrated aircraft as part of GVTexpertise. The introduction of the (Ground Vibration Testing) campaigns,Polymax algorithm by Siemens has supporting the aircraft certificationalready led to significant improvement, process. Next to this, the modal surveyproviding more clarity in the stabilization technique, commonly used in the spacediagrams. But verifying that the modal industry, helps verify the structuralmodel fits well with the measured data is dynamics performance of spacecraft andstill a tedious task that might require space launchers.many successive iterations. 90'