scholarly journals The Shear Stress and the Normal Stress Difference of Polymer Melts

1977 ◽  
Vol 43 (370) ◽  
pp. 2091-2099
Author(s):  
Seisuke OKUBO ◽  
Yukio HORI
Keyword(s):  
Shear Stress ◽  
Normal Stress ◽  
Polymer Melts ◽  
Normal Stress Difference ◽  
Stress Difference

Suspensions in a tilted trough: second normal stress difference

2011 ◽  
Vol 686 ◽  
pp. 26-39 ◽  
Author(s):  
Étienne Couturier ◽  
François Boyer ◽  
Olivier Pouliquen ◽  
Élisabeth Guazzelli
Keyword(s):  
Shear Stress ◽  
Normal Stress ◽  
Volume Fraction ◽  
Behavioural Change ◽  
Normal Stress Difference ◽  
Stress Difference ◽  
Rigid Spheres ◽  
First Normal Stress Difference ◽  
Second Normal Stress Difference ◽  
Neutrally Buoyant

AbstractWe measure the second normal-stress difference in suspensions of non-Brownian neutrally buoyant rigid spheres dispersed in a Newtonian fluid. We use a method inspired by Wineman & Pipkin (Acta Mechanica, vol. 2, 1966, pp. 104–115) and Tanner (Trans. Soc. Rheol., vol. 14, 1970, pp. 483–507), which relies on the examination of the shape of the suspension free surface in a tilted trough flow. The second normal-stress difference is found to be negative and linear in shear stress. The ratio of the second normal-stress difference to shear stress increases with increasing volume fraction. A clear behavioural change exhibiting a strong (approximately linear) growth in the magnitude of this ratio with volume fraction is seen above a volume fraction of 0.22. By comparing our results with previous data obtained for the same batch of spheres by Boyer, Pouliquen & Guazzeli (J. Fluid Mech., 2011, doi:10.1017/jfm.2011.272), the ratio of the first normal-stress difference to the shear stress is estimated and its magnitude is found to be very small.

Four-Wire Bridge Measurements of van der Pauw Stress Sensors on (100) and (111) Silicon

2013 ◽  
Author(s):  
Richard C. Jaeger ◽  
Mohammad Motalab ◽  
Safina Hussain ◽  
Jeffrey C. Suhling
Keyword(s):  
Shear Stress ◽  
Normal Stress ◽  
Normal Stress Difference ◽  
Stress Difference ◽  
Plane Shear ◽  
Plane Normal ◽  
Stress Sensors ◽  
Van Der Pauw ◽  
Contact Sensors

Four-wire resistance characterization of van der Pauw stress sensors is discussed. Under the proper orientations and excitations, the output of the four-contact sensors can be shown to depend upon only the in-plane shear stress or the in-plane normal stress difference on (100) silicon. The other stress terms are cancelled out by the symmetry of the structure, and the measurements are inherently temperature compensated. In bridge-mode, each sensor requires only one measurement and produces an output voltage that is directly proportional to the shear stress or in-plane normal stress difference, and the sensitivity is 3.16 times that of the equivalent resistor sensors, just as in the normal van der Pauw mode. Experimental, theoretical, finite-difference and finite-element and simulation results are presented demonstrating the behavior of the sensor. The two sensors can be merged into one eight-contact device, or n- and p-tye sensors can be overlaid in standard IC processes. Similar results apply to sensors on (111) silicon.

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