Experimental Modal Analysis on a Tyre - Lessons Learned

Extracting the mode shapes of a tyre can be very challenging, particularly for the transverse and the longitudinal mode shapes. The current paper presents results for experimental modal analysis (EMA) tests on a tyre using both an impact hammer and an electro-dynamic shaker. The radial modes of the tyre were excited using a modal impact hammer. The possibility of using a narrow metal screw that could be attached to the modal impact hammer to excite the transverse and torsional mode shapes of the tyre was studied. The advantages and drawbacks of using a mechanical shaker to excite the structure and using roving accelerometers to measure the response were also studied. This study also describes a method to extract the repeated roots of a tyre using the experimental modal analysis. The current paper summarises the lessons learned from different experiment cases that were performed to extract mode shapes of a tyre