Klein Lecture in Aerospace
This series of lectures is given in memory of Professor Arthur Louis "Maj" Klein (1898-1983), a faculty member of GALCIT from 1929 until his death. In addition to his significant contributions as a teacher of aeronautical engineering, Klein was responsible for the engineering and building of the GALCIT 10-foot wind tunnel and made significant contributions to aircraft design.
Date: April 11, 2025, 3:00 PM
Location: Lees-Kubota Lecture Hall
Speaker: John W. Hutchinson, School of Engineering and Applied Sciences, Harvard University
Shell Buckling: A Subject That Never Grows Old
The stability of structures continues to be scientifically fascinating and technically important. Shell buckling emerged as one of the most challenging nonlinear problems in mechanics sixty years ago when it was intensively studied, with Caltech being one of the leading centers of activity. The subject has returned to life motivated not only by structural applications but also by developments in life sciences concerning soft materials. Efforts are underway in the US, China and Europe to update existing design codes for shell buckling to take account of computational and experimental advances which have occurred in the last six decades, promising to enable significantly less conservative designs against buckling. The challenge is that shell structures are susceptible to catastrophic collapse and dramatic load-carrying reductions due to relatively small imperfections in their geometry. Imperfections must be factored into buckling load estimations. Most modern aerospace shells are either metallic reinforced with stiffeners or fiber reinforced composites, in each case manufactured to high levels of precision. This precision, and recent theoretical developments, have made it possible to design shell structures that are substantially lighter than those the design codes from 60 years ago allow. These developments will be highlighted in the seminar, complemented by a presentation of current experimental and theoretical work underway by the author and his collaborators on the imperfection-sensitivity of stiffened shell structures. Every attempt will be made to make the subject assessable to a broad engineering audience.
John W. Hutchinson
School of Engineering and Applied Sciences, Harvard University
John Hutchinson received his undergraduate education in engineering mechanics at Lehigh University and his graduate education in mechanical engineering at Harvard University. He joined the Harvard faculty in the School of Engineering and Applied Sciences in 1964 and is currently the Abbott and James Lawrence Professor of Engineering Emeritus. Hutchinson and his collaborators work on problems in solid mechanics concerned with engineering materials and structures. Buckling, structural stability, elasticity, plasticity, fracture, and micro-mechanics are all central in their research. Ongoing research activities are: (1) development of a mechanics framework for assessing the durability of thermal barrier coatings for gas turbine engines, (2) fracture mechanics of tough ductile alloys, (3) the development of a theory for micron scale plasticity, and (4) stability phenomena in plates, shells and soft materials. Further information and publications can be downloaded at http://www.seas.harvard.edu/hutchinson.