Uniaxial Elongation and Craze Growth in Glassy Polymers.

A simulation of craze growth in glassy polymers during uniaxial elongation was conducted using the MD engines GOGNAC and VSOP. Calculations using Langevin dynamics (Kremer-Grest model) were carried out according to Reference (1).

Figs. 1 and 2 show the calculation results for two systems with different molecular masses (number of particles per polymer chain). The void and fibril formation can be confirmed, and the effect of the difference in the molecular mass is evaluated.

Fig.1 Snapshots of craze growth for polymer chains with N=128.

Fig.2 Snapshots of craze growth for polymer chains with N=512.

Fig.3 shows the stress-strain curves estimated from the results in Figs. 1 and 2. In the N=128 system, the stress decreases after yield; on the other hand, the stress increases after fibril formation in the N=512 system.

Fig. 3 Stress-Strain curve