Beat Tuning of Great Bell of 2018 Pyeongchang Winter Olympics

The Great Bell of 2018 Pyeongchang Winter Olympics (Olympic Bell) was built to symbolize hope for the successful hosting of the 2018 Winter Olympics. Olympic Bell was designed to provide a dynamic sound at the world sports festival in the form of a traditional Korean bell shaped like a jar. For the dynamic sound of the bell, the beating sound should be clear and not too short or too long. However, beating was not predictable at the design stage because it was caused by the minute asymmetry in the casting process. After the casting, the beat period of the Olympic Bell was too long for the sound to be heard as desired. In this study, we improved the beat period using an equivalent bell model. A finite element model of the equivalent bell was constructed using the measured vibration modes that compose the beat. The change in beat period was analytically determined while gradually reducing the local thickness of the equivalent bell model. As a result, we created a strong and appropriate period of beat, and experimently confirmed that it produces powerful, dynamic sounds.