The determination of Poisson's ratio compliances for polyethylene terephthalate sheets using a Michelson interferometer

Uniaxial, shear, and poisson relaxation and their conversion to bulk relaxation: Studies on poly(methyl methacrylate)

“…8 with the shift factors shown in FYg. 7. The Poisson master curve produced in this way is more narrowly bounded.…”

“…The temperature and time dependent Poisson's ratio, u(t), has not been measured directly in the transition range, though Poisson's ratio in the "glassy" state has been measured repeatedly as a (limited) function of time: Gilmour et al (5) tion of a freely supported circular plate under uniformly distributed pressure for PMMA and PVC materials at room temperature. However, the experimental methods employed in these studies, except possibly the optical ones (6,7). lead to serious difficulties when applied over a wide range of temperatures.…”

Molecular orientation in biaxially oriented sheets of poly(ethylene terephthalate) II. Correlation of orientation averages with measured mechanical compliances

“…The extensional compliances Sll and S, were measured by means of a modified form of the dead-loading extensional creep apparatus of Gupta and Ward, lo and the torsional compliances S, and S, were measured by the simple-shear method." The whole set of nine compliances for the 5 1 sheet had already been measured.12 For this set of results, use was also made of a torsional creep method13J4 to determine all three shear compliances S,, Ss5, and S, (the results were found12 to agree with those determined by the simple-shear method for S , and S,), a 16 compression method15 for S22, an optical interference technique16 for SI2 and S23, and the electron microscope grid method of Ladizesky and for SI3.…”