Abstract: Bells have been cast by bell founders in Northern Europe since the Middle Ages. In those days, casting a pleasant sounding bell or even a pure ringing bell was merely a matter of luck. The global shape of the traditional bells emerged from experiments over many years. Some years ago, a new type of Carillon bell has been developed at the Eindhoven University of Techology by using numerical shape optimization. In this bell, the traditional minor-third chord, formed by the lowest partials, was replaced by a major-third cord. Here, a partial is the sound field that is radiated by a structural eigenmode of the bell. Carillons have been built composed of the new bell type. However, perceptual evaluation of the new Carillons showed that optimization of the frequencies of the partials alone is not sufficient to ensure a qualitatively good sound spectrum. It is necessary to incorporate other characteristics of the sound spectrum in the optimization process as well, in particular, the decay rate of the individual partials. Recently, the extended optimization process has resulted in a modified shape of the major-third Carillon bell showing an improved sound spectrum. The presentation will elucidate the major steps in the development of the major-third Carillon bell, and in particular, address some relevant aspects of the optimization process.

Biography: Dr. van Campen completed his Engineering Thesis in Engineering Mechanics at the Delft University of Technology in 1966 under the advice of Professor Koiter and his Ph.D. Thesis in Energy Technology at the Delft University of Technology in 1972 under the advice of Professor Latzko. His research fields are nonlinear dynamics, structural optimization, and biomechanics. Dr. van Campen had an industrial training period at Royal Dutch Shell Campany from 1972 to 1974. He has been an Associate Professor of Engineering Mechanics at Twente University from 1974 to 1979, a Professor of Engineering Mechanics at Twente University from 1980 to 1984, and a Professor of Engineering Mechanics at Eindhoven University of Technology from 1984 to date. He has also been a Dean of the Faculty of Mechanical Engineering from 1990 to 1994. Dr. van Campen is the Scientific Director of Stevin Centre for Computational and Experimental Engineering Science from 1991 to date and the Scientific Director of the Dutch National Research School (Graduate School) of Engineering Mechanics from January 1997 to the present time. He is also a council member of the Dutch Technology Foundation. Dr. van Campen is a member of the advisory board of Nonlinear Dynamics, an associate editor of Applied Mechanics Reviews, and a contributing editor of Multibody System Dynamics. He is also a honorary professor of South West Jiatong University, Chengdu, China from 1995. He has co-authored more than 150 publications in the international literature and delivered many keynote and invited lectures at numerous international conferences.

Time:March 31, 2000 @ 2:30 P.M
Place:Room 1202, Martin Hall
Hosts: Professors S. Azarm and B. Balachandran, Department of Mechanical Engineering