標題: Precrack hysteresis energy in determining polycarbonate ductile-brittle transition .4. Effect of strain rate
作者: Chiou, KC
Hsu, HC
Chang, FC
應用化學系
Department of Applied Chemistry
關鍵字: polycarbonate;ductile-brittle transition;hysteresis;strain rate
公開日期: 25-七月-1997
摘要: Effect of deformation rate on the ductile-brittle transition behavior for polycarbonate (PC) with different molar mass, notch radius, and rubber content has been investigated. PC with higher molar mass, notch radius, or rubber-modification possesses a higher critical strain rate when the ductile-brittle transition occurs. Whether a notched specimen will fail in a ductile mode or a brittle mode is already decided before the onset of the crack initiation. If size of the precrack plastic zone exceeds a critical level prior to onset of crack initiation, the crack extension developed later will propagate within the plastic zone and result in a ductile mode fracture. The precrack elastic storage energy, the input energy subtracting the hysteresis energy, is the main driving force to strain the crack tip for crack initiation. The precrack hysteresis energy (directly related to the precrack plasticity) increases with the decrease of the applied strain rate. Therefore, the strain rate is also closely related to the size of the precrack plastic zone. If the strain rate is lower than the critical strain rate, the specimen is able to grow a precrack plastic zone exceeding the critical plastic zone and results in a ductile mode fracture. (C) 1997 John Wiley & Sons, Inc.
URI: http://hdl.handle.net/11536/433
ISSN: 0021-8995
期刊: JOURNAL OF APPLIED POLYMER SCIENCE
Volume: 65
Issue: 4
起始頁: 655
結束頁: 665
顯示於類別:期刊論文


文件中的檔案:

  1. A1997XG78700004.pdf