Localization of deformation in thin shells under indentation

We perform a hybrid experimental and numerical study of the localization of deformation in thin spherical elastic shells under indentation. Past a critical indentation, the deformation of the shell ceases to be axisymmetric and sharp points of localized curvature form. In plates, these sharp points are known as d-cones. By way of analogy, regions of localization in shells are referred to as s-cones, for 'shell-cones'. We quantify how the formation and evolution of s-cones is affected by the indenter's curvature. Juxtaposing results from precision model experiments and Finite Element simulations enables the exploration of the frictional nature of the shell-indenter contact. The numerics also allow for a characterization of the relative properties of strain energy focusing, at the different loci of localization. The predictive power of the numerics is taken advantage of to further explore parameter space and perform numerical experiments that are not easily conducted physically. This combined experimental and computational approach allows us to gain invaluable physical insight towards rationalizing this geometrically nonlinear process.

Department dc:contributor.department

Massachusetts Institute of Technology. Department of Mechanical Engineering.

Grantor dc:publisher

Massachusetts Institute of Technology

Year dc:date.issued

2013

Author dc:creator

• Nasto, Alice M. (Alice Meite)

Advisor dc:contributor.advisor

• Pedro M. Reis.

• Mechanical Engineering.

Statement dc:rights

• M.I.T. theses are protected by copyright. They may be viewed from this source for any purpose, but reproduction or distribution in any format is prohibited without written permission. See provided URL for inquiries about permission.

Licence dc:rights.uri

• http://dspace.mit.edu/handle/1721.1/7582

Language dc:language.iso

eng

Handle dc:identifier.uri

http://hdl.handle.net/1721.1/85477

OAI identifier oai:identifier

oai:dspace.mit.edu:1721.1/85477