Sharp notch fracture parameters

The studies carried out earlier have shown that polymer film samples strength to a considerable extent is defined by growth parameters of stable crack in local deformation zone (ZD) at a notch tip [1-3], As it has been shown in Refs. [4, 5], the fiactal concept can be used successfully for the similar processes analysis. This concept is used particularly successfully for the relationships between fracture processes on different levels and subjecting fracture material microstructure derivation [5]. This problem is of the interest in one more respect. As it has been shown earlier, both amorphous polymers structure [7] and Griffith crack [4] are fractals. Therefore, the possibility to establish these objects fractal characteristics intercommunication appears. The authors of Refs. [8, 9] consider stable cracks in polyarylatesul-fone (PASF) film samples treatment as fractals and obtain intercommunication of this polymer structure characteristics with samples with sharp notch fracture parameters. 

Five typical polymer samples were selected for the considered effects quantitative estimation PS and HDPE, showing superplasticity availability PVS, showing intermediate behavior (it breaks down immediately beyond yield stress) typical brittle PMMA and HDPE samples with sharp notch on length 1.5 mm, showing also brittle fracture. The necessary rated parameters for them in elastic and viscoelastic (up to yield stress) and plastic (beyond yield stress) regions are adduced in Table 10.1. 

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