1. SPOKE TUNER STATUS M. Merio, D. Passarelli, L. Ristori

2. Spoke Tuning System Requirementsvalueunit Cavity and Mechanical system specs Cavity end-wall spring constant30000.00N/mm Cavity elastic sensitivity at end-wall540.00kHz/mm Frequency range necessary for operation135.00kHz Stroke at BP0.25mm Max force at BP7500.00N Mech advantage between BP-NUT (RBPN)0.17 Mech advantage between BP-PIEZO (RBPP)0.50 Elastic efficiency between BP-NUT (EBPN)0.25 Elastic efficiency between BP-PIEZO (EBPP)0.25 Transmission coefficient from NUT (RBPNxEBPN)0.04 Transmission coefficient from PIEZO (RBPPxEBPP)0.13 Piezoelectric actuators specs (Fine tuning) Max force3750.00N Frequency range1.00kHz Stroke at BP1.85um Stroke cold14.81um Actuator assembly specs (Coarse tuning) Max Force at Nut pushing (safety operation)non-issueN Max Force at Nut pulling (normal operation)1250.00N Stroke6.00mm Frequency resolution0.02kHz Axial resolution at Nut888.89nm Lifetime linear travel of Nut1500.00mm

3. MODEL AND ASSUMPTIONS L/2 L S S/3 FULCRUM MAIN ARM PROBES Motor arm Drive nut STEPPER MOTOR PIEZOS Stretch adjustment Squeeze adjustment Assumptions: The Tuner is symmetric, only half model will be considered Material: SS316 L RT analysis Tuner with symmetry boundary conditions imposed

4. TUNER MAIN ARM Loads and Boundary Conditions:

5. MOTOR ARM – Load @ PIEZO Loads and Boundary Conditions:

6. MOTOR ARM – Load @ MOTOR Loads and Boundary Conditions:

7. MOTOR SUPPORT Loads and Boundary Conditions:

8. PLATE Loads and Boundary Conditions: Total Force acting on the bolts: Bolt 1Bolt 2Bolt 3Bolt 4 Force [N]925.94645.41422.08262.85

9. CONCLUSIONS A first coarse analysis has been done to evaluate the behavior of the main components of the tuner Stiffness and Stresses have been investigated Future work: Verify if the requirements listed before have been satisfied Thermal analysis Analysis of the entire assembly Failure analysis THANKS FOR THE ATTENTION