کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
279771 1430354 2008 17 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
On the importance of thermo-elastic cooling in the fracture of glassy polymers at high rates
موضوعات مرتبط
مهندسی و علوم پایه سایر رشته های مهندسی مهندسی عمران و سازه
پیش نمایش صفحه اول مقاله
On the importance of thermo-elastic cooling in the fracture of glassy polymers at high rates
چکیده انگلیسی

In a previous thermo-mechanical analysis [Estevez, R., Basu, S., van der Giessen, E., 2005. Analysis of temperature effects near mode I cracks in glassy polymers. Int. J. Fract. 132, 249–273] in which shear yielding of the bulk and failure by crazing were accounted for, we examined which of these two viscoplastic processes contributed to heat in mode I fracture. The present study completes this work by investigating the conditions for thermo-elastic cooling prior to crack propagation as reported experimentally by Rittel [Rittel, D., 1998. Experimental investigation of transient thermo-elastic effects in dynamic fracture. Int. J. Solids Struct. 35, 2959–2973] and Bougaut and Rittel [Bougaut, O., Rittel, D., 2001. On crack tip cooling during dynamic crack propagation. Int. J. Solids Struct. 38, 2517–2532] on high strain rate loading of PMMA. To this end, coupled thermo-mechanical finite element simulations are carried out by accounting for the thermo-elastic source, in addition to the heat sources related to shear yielding and crazing. The bulk as well as cohesive zone parameters for crazing realistically describe PMMA as they are obtained from detailed calibration experiments. Our results show that if significant thermo-elastic cooling has to be observed in the vicinity of the crack tip of a polymeric material, suppression of shear yielding as well as suppression of crazing is necessary. It seems that at these high strain rates a brittle fracture mechanism activated at very high stresses takes over from crazing, or at least that craze initiation occurs for stress levels very different to those for quasi-static conditions.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: International Journal of Solids and Structures - Volume 45, Issues 11–12, 15 June 2008, Pages 3449–3465
نویسندگان
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