The disentanglement time of the craze fibrils under cyclic loading

✍ Scribed by R. Schirrer; J. Le Masson; B. Tomatis; R. Lang

• Publisher: Society for Plastic Engineers
• Year: 1984
• Tongue: English
• Weight: 476 KB
• Volume: 24
• Category: Article
• ISSN: 0032-3888
• DOI: 10.1002/pen.760241012

✦ Synopsis

Abstract

In a previous publication a breaking or disentanglement‐time was defined for the fibrils in the craze at the tip of a steady‐state moving crack. In this paper the case of a cyclic sinus loading is investigated, whereas in the previous one the case of a static loading was studied. In both cases the craze fibrils break due to a thermally activated process. The apparent activation energy corresponds to that of the secondary relaxation peak (b̃) in poly(methyl methacrylate). Under cyclic loading conditions the breaking time may be expressed as a time or as a number of cycles carried by the fibrils before breakage. It seems that the relevant parameter is the time rather than the number of cycles. At high frequencies and temperatures an hysteretic heating effect has been detected by means of the breaking‐time of the fibrils.