Elasticstressandstrain - Carnegie Mellon University

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Elasticstressandstrain Kittel ch 3 Uniform dilation Uniform shear constant Volume V v n T h dilation S simple shear Who pure shear Vo ho Localstrain Fi's it Fi local displacement Tier de Y.i FitiicrI Strain Var iation of it F up f F de ti Separation DI Fi Fi DEI Fi Fi DI dii Idi t IDI't t 2dL die't OHH ha dry Strainteri Ug I t 3 symmetric dimensionless Idf 12 Idf th t 2Uijdridr t Ui 6 independent strains Uxx Ux y 4 2 Dilation S Tr Uig Uyy Uyz Uzz

Transcript of Elasticstressandstrain - Carnegie Mellon University

Page 1: Elasticstressandstrain - Carnegie Mellon University

Elasticstressandstrain Kittel ch 3

Uniform dilation Uniform shear constant VolumeV

v n T h

dilation S simpleshearWho pure shearVo ho

Localstrain Fi's itFi

local displacement Tier de Y.i FitiicrIStrain Var iation of it F

up fF de ti

Separation DI Fi Fi DEIFi Fi DI dii

Idi t IDI't t 2dL die't OHH hadry

Strainteri Ug I t 3 symmetric dimensionless

Idf12 Idfth t 2Uijdridr t Ui 6 independent strains

Uxx Uxy 4 2

Dilation S Tr Uig Uyy UyzUzz

Page 2: Elasticstressandstrain - Carnegie Mellon University

Stress response to strain

z tf faceEforce Stress tensor

µ I 0h2 faceof i force ong face g areay t 1 face

faceJi Tj for no net torque

x faceUnits forcelarea energylvolum

pressureHooke's law

spring f k nkmM

integrated E zkx2

Solid body Tig KijmnUmm

integrated I KijmnUijUmindependent

Elements of Kijmn ijmn x y z 34 81 elementsor

index symmetries i c Xji Mn nm ij mu 21

Crystalsymmetries cubic 3 isotropic 2 bulk shear

Netf orceA A A

T x tax 4 1 13AYAZIi i1921 1 7 04 13AxAy

F TT LAXAyaz Force density I Volume