Sinos: Física e música fundidas em bronze

Abstract

Bells are percussion instruments from the idiophones family, being devices to produce sound which are simpleonly in appearance. The bells bodies are made of an alloy called bronze, which is a combination of copper andtin in a variable ratio. Inside the bell there is the clapper, a pendulum that hits the bell from inside in order tostart the sound. Bell foundry is quite complex and involves a large number of procedures which range from theconstruction of the molds until the metallurgy and its tuning. The modern bell suffered only minor changes in itsshape when compared to the first casted bells from the 9th century. Complex mathematical methods are neededto create acoustical models for vibrating bells and, due to their exaggerated size, it is difficult to transport themto a laboratory in order to perform experimental analysis. This article presents a brief discussion on the origin,history and uses of the bell, as well as the main steps in the casting process and the physical description of thevibrating bell.