• 作者： Lee, Chang-Bing; Lu, Ming-Luen; Chang, Feng-Chih
• 中文摘要： 本研究使用ASTM E813-87之標準法及改良法來鑑定強化聚碳酸脂的破壞韌性,並將所得的Jc值與先前經由ASTM E813-81,遲滯能與應力泛白等方法所得Jc值比較。對於一般高分子材料,Jc值由E813-81法或遲滯能法所得為高,若將原來E813-87方法中所採用的平行線由原訂的0.2mm改為0.1mm,則所求得的Jc值差異不大。若將原來E813-81方法中的鈍化線取消,也就是鈍化現象不予考慮則所得Jc值偏低。高分子材料的本質將決定裂縫尖端是鈍化、半鈍化或是不鈍化。若以裂縫的成長起始來訂Jc,則對一般會明顯鈍化的材料(如橡膠強化聚碳酸脂),E813-81的方法較適合。對於一般以裂痕為主要破壞機構的材料(如強化聚苯己烯),則改良型的E813-81法較為適合,而遲滯能法不僅在實驗上較簡易,且可自動調整裂縫尖端鈍化所造成的效應。
• 英文摘要： The ASTM E813-87 standard and its modified version were used to characterize the fracture toughness of the elastomer modified polycarbonates and the resultant Jcs were then put into comparison with the results from E813-81, modified E813-81, hysteresis energy, and the stress whitening methods. The E813-87 method resulted in relatively higher Jc values for polymers. The modified version of E813- 87, however, gave more comparable Jc values as those obtained from the E813-81 or the hysteresis method through means of moving the offset line from the original 0.2 to 0.1mm. The modified E813-81 method resulted in relatively lower Jc values for the elastomer toughened polycarbonates by neglecting the crack blunting. The nature of polymers would determine whether the crack tip would become blunted, partially blunted, or not blunted. The ASTM E813-81 method, in regard to crack initiation, is more appropriate for those polymers with a well-defined blunted crack tip, i.e. elastomer modified polycarbonate. The modified version of E813-81 by neglecting the crack blunting line, meanwhile, seems better for those polymers with craze as the main failure mechanism, i.e. high impact polystyrene(HIPS). The hysteresis energy method is relatively simple with the capability of inherently adjusting the blunting effect.
• 中文關鍵字： J積分法; 破壞力學; 聚碳酸脂; 遲滯效應; 應力泛白; 裂縫尖端; 斷裂韌性
• 英文關鍵字： J-Integral; Fracture Mechanics; Polycarbonate; Hysteresis; Stress Whitening; Crack Blunting; Fracture Toughness