TY - JOUR
T1 - Relaxation of shear and normal stress components in step-strain experiments
AU - Vrentas, C. M.
AU - Graessley, W. W.
N1 - Funding Information:
This work was supported by a grant from the Nattonal Science Foundation (ENG 77-l5683-AOI) We are grateful for use of the facrlrtres of the Northwestern Umverslty Materials Research Center We also thank Professor A S Lodge for provtdmg a preprint of ref 7 prior to publrc;rtton
PY - 1981
Y1 - 1981
N2 - The relaxation of torque and axial thrust following a rapidly imposed step in shear strain ( 0 < γ ≤ 3.33) was measured for several undiluted polymers and polymer solutions using the cone-and-plate geometry in a Rheometrics mechanical spectrometer. Instrumental response times were favorable for calculating both the shear stress σ(γ, t) and the first normal stress difference N1(γ,t) from torque and thrust data on two of the solutions. Those results confirm the relationship N1(γ,t) = γσ(γ, t). Apparent departures from this relationship appear if σ(γ,t) and N1(σ, t are calculated from torque and thrust data when the instrumental response criteria are not met.
AB - The relaxation of torque and axial thrust following a rapidly imposed step in shear strain ( 0 < γ ≤ 3.33) was measured for several undiluted polymers and polymer solutions using the cone-and-plate geometry in a Rheometrics mechanical spectrometer. Instrumental response times were favorable for calculating both the shear stress σ(γ, t) and the first normal stress difference N1(γ,t) from torque and thrust data on two of the solutions. Those results confirm the relationship N1(γ,t) = γσ(γ, t). Apparent departures from this relationship appear if σ(γ,t) and N1(σ, t are calculated from torque and thrust data when the instrumental response criteria are not met.
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U2 - 10.1016/0377-0257(81)85009-4
DO - 10.1016/0377-0257(81)85009-4
M3 - Article
AN - SCOPUS:0019649423
SN - 0377-0257
VL - 9
SP - 339
EP - 355
JO - Journal of Non-Newtonian Fluid Mechanics
JF - Journal of Non-Newtonian Fluid Mechanics
IS - 3-4
ER -