KIC Determination—a non-standard approach

✍ Scribed by M.O. Lai

• Publisher: Elsevier Science
• Year: 1991
• Tongue: English
• Weight: 285 KB
• Volume: 39
• Category: Article
• ISSN: 0013-7944
• DOI: 10.1016/0013-7944(91)90051-2

✦ Synopsis

Ah&a&--The ballizing process of forcing a 19.06 mm diameter tungsten carbide ball through a slightfy undersize 18.70 mm diameter bore has been used in the present investigation to determine the fracture toughness of polymethyl methacrylate. The specimen consisted of a 10.65 mm wall thickness thick-walled cyiinder. A notch of constant depth was machined on the outer surface in the direction of the axis of the cylinder. The depth of the notch was increased such that when the specimen was ballized, a crack was generated from the notch. The critical crack depth was found to be 2.0 mm. With this depth, fracture toughness of the material was determined using thick-walled cylinder theory together with the appropriate stress intensity factor. Fracture toughness of the material was also determined using standard 3-point bend specimens according to ASTM E399-81 standard procedures. It was found that the result from the ballizing process closely estimated that from the standard test.