Analysis of a force and moment measurement system for a transonic wind tunnel

Abstract: Low eigenfrequency force and moment measurement systems used for aero-elastic wind tunnel investigations of airplane wing models have been found prone to resonance at dynamic loading. A new suggested design characterized by having high eigenfrequencies and believed suitable for measurements in such experiments is analyzed in the present work. Flexibility and frequency response characteristics of the studied device including piezo electric transducers mounted in a balance are studied using finite element software. Stress levels are found low in general except for a pin experiencing high shear stress. Reasons for this are discussed. The found modal characteristics provide a basis for further experimental investigations.