Brookeld Engineering Labs., Inc. Page 84 Manual No. M13-167-A0415
VII.3 The Bingham Model
τ
=
τ
o
+ hD
(τ
=shearstress, τ
o
=yieldstress,h =plasticviscosity,and D =shearrate)
What does it tell you?
TheBinghammodelindicatesaproduct’syieldstress,τ
o
,whichistheamountofshearstress
requiredtoinitiateow.Italsoprovidestheplasticviscosity,
h,whichistheviscosityaftera
productyields.
Figure VII-3
When should you use it?
Thismodelshouldbeusedwithnon-Newtonianmaterialsthathaveayieldstressandthenbehave
inaNewtonianfashiononcetheybegintoow.Asaresult,theshearstress-shearrateplotforms
astraightlineafteryielding.(Productsthathaveayieldstressonlybegintoowafteracertain
amountofshearstressisapplied.Theyarealsocalled“viscoplastic”.Theirshearstressvs.shear
rategraphsintersectthey-axisatapointgreaterthan0.)