Brookfield DV3T Rheometer Manuale Utente Scaricare il pdf (Pagina 87)

Brookeld Engineering Labs., Inc. Page 87 Manual No. M13-2100

VII.3 The Bingham Model

+ hD

(τ

=shearstress, τ

=yieldstress,h =plasticviscosity,and D =shearrate)

What does it tell you?

TheBinghammodelindicatesaproduct’syieldstress,τ

,whichistheamountofshearstress

requiredtoinitiateow.Italsoprovidestheplasticviscosity,

h,whichistheviscosityaftera

product yields.

Figure VII-3

When should you use it?

Thismodelshouldbeusedwithnon-Newtonianmaterialsthathaveayieldstressandthenbehave

inaNewtonianfashiononcetheybegintoow.Asaresult,theshearstress-shearrateplotforms

astraightlineafteryielding.(Productsthathaveayieldstressonlybegintoowafteracertain

amountofshearstressisapplied.Theyarealsocalled“viscoplastic”.Theirshearstressvs.shear

rategraphsintersectthey-axisatapointgreaterthan0.)

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Brookfield DV3T Rheometer Manuale Utente Pagina 87