Is smaller always stiffer? On size effects in supposedly generalized continua

M.A. Wheel, J.C. Frame, P.E. Riches

Research output: Contribution to journalArticle

17 Citations (Scopus)

Abstract

Heterogeneous materials having constitutive behaviour described by more generalized continuum theories incorporating additional degrees of freedom such as couple stress, micropolar or micromorphic elasticity are expected to exhibit size effects in which there is an apparent increase in stiffness as the size scale reduces. Here we briefly demonstrate that for a simple heterogeneous material the size effect predicted when loaded in bending depends on the nature of the sample surface. Diverse size effects may thus be exhibited by the same material. We then show by detailed finite element analysis of a more representative material with regular heterogeneity that this diversity of size effects might actually be observed in practice thereby providing an explanation for the contradictory size effects that have sometimes been reported for real materials.
LanguageEnglish
Pages84-92
Number of pages9
JournalInternational Journal of Solids and Structures
Volume67-68
Early online date13 Apr 2015
DOIs
Publication statusPublished - 15 Aug 2015

Fingerprint

Size Effect
Continuum
continuums
Heterogeneous Materials
Constitutive Behavior
Couple Stress
Micropolar
Degrees of freedom (mechanics)
Elasticity
Stiffness
Degree of freedom
stiffness
Finite Element
Finite element method
elastic properties
degrees of freedom
Demonstrate

Keywords

  • heterogeneous material
  • size effects
  • finite element analysis
  • elasticity

Cite this

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Is smaller always stiffer? On size effects in supposedly generalized continua. / Wheel, M.A.; Frame, J.C.; Riches, P.E.

In: International Journal of Solids and Structures, Vol. 67-68, 15.08.2015, p. 84-92.

Research output: Contribution to journalArticle

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