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 fifty years ago when it was intensively studied, and it has returned to life with new challenges motivated not only by structural applications but also by developments in the life sciences concerning soft materials. It is not at all uncommon for slightly imperfect thin cylindrical shells under axial compression or spherical shells under external pressure to buckle at 20% of the buckling load of the perfect shell. A historical overview of these aspects of shell buckling will be presented with the non-specialist in mind followed by a discussion of recent work by the speaker and several collaborators on the buckling of spherical shells. Experimental and theoretical work will be described with a focus on imperfection-sensitivity and on viewing the phenomena within the larger context of nonlinear stability.
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 Lawrence Research Professor of Engineering. 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 relevant 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 mechanics of thin films, coatings and multilayers, and (4) shell buckling. Further information and publications can be downloaded at http://www.seas.harvard.edu/hutchinson