Size-dependent yield strength and surface energies of thin films
2005 (English)In: Materials Science & Engineering: A, ISSN 0921-5093, Vol. 400-401, no 1-2 SUPPL., 448-450 p.Article in journal (Refereed) Published
The strain gradient plasticity theory recently proposed by Gudmundson [P. Gudmundson, J. Mech. Phys. Solids 52 (2004) 1379-1406] is used to analyse the behaviour of a thin film on an elastic substrate. Boundary conditions for the film-substrate interface are introduced via a surface energy that depends on the plastic strain state at the interface. Finite element results show a strong dependence on the surface energy. If the surface energy is small, no size effects appear. On the other hand, if a stiff interface is simulated, corresponding to a large surface energy, a thickness dependence of the yield strength is found. The application of several alternative strain gradient models would predict a thickness dependent hardening, but strictly not a size dependence of the yield strength. The presently predicted thickness dependence on yield strength and hardening is supported by experimental results.
Place, publisher, year, edition, pages
2005. Vol. 400-401, no 1-2 SUPPL., 448-450 p.
constitutive behaviour, strain gradient plasticity, strain gradient plasticity
IdentifiersURN: urn:nbn:se:kth:diva-14930DOI: 10.1016/j.msea.2005.02.090ISI: 000230681900093ScopusID: 2-s2.0-21644487900OAI: oai:DiVA.org:kth-14930DiVA: diva2:332971
QC 20100525 QC 201110112010-08-052010-08-052011-10-11Bibliographically approved