The rudderless Jian, meanwhile, soon loses his passion for his studies and spends his afternoons parsing his teacher's crazed
lectures for truths that might help him chart his own course in life.
After being crazed to the desired level, each sample was equilibrated in a small dessicator to 11.
The mechanical performance of crazed polycarbonate was characterized by measuring the yield stress, elastic modulus, failure stress, and ductility for constant strain rate tensile tests.
In an attempt to build a model to predict the residual mechanical properties of crazed polycarbonate, several samples were crazed to a relative craze density of 10% at 40, 45, and 50 MPa.
The following procedure outlines the general steps to follow to measure the residual mechanical properties of crazed samples.
The first mechanical property of crazed polycarbonate to be considered in the two-factor model was yield stress.
Using the data in Table 3, the constant and coefficients for the predictive model for the yield stress of crazed polycarbonate were calculated and are shown in Table 4.
5, the optical micrographs of the DN-4PB specimen clearly indicate that a crazed zone is formed in front of the crack tip (Fig.
With increasing strain, a large fan-shape crazed zone is generated and a shear yielded zone at the center of the crazed zone is initiated around the crack tip.
However, there exist an intense damage strip along the crack wake and ahead of the crack tip, and a larger overall crazed zone in PP/SEP specimen.
In some cases, no crazes were observed for the i-PP film that was crazed in the smallest glass cones.
In order to study the craze pathway into the structure of the semicrystalline polymer, etching of the i-PP(130) sample was performed after it was crazed in the presence of n-propanol.
The first three samples had a relatively large critical strain or did not craze at all, whereas the other samples crazed very well, more or less depending on the solvent used and the sample studied.
12] are independent elastic moduli of the crazed material.
A] uniquely characterizes the loading sensed by the crazed region ahead of the crack if the SSY condition Eq 1a is satisfied.