Toughness of plastics

The commonest way of measuring the toughness of plastic and composites is by means of impact test. The specimen is supported at each and struck at the centre so that it is rapidly loaded in three point bend (Charpy impact test). In This experiment the specimen was unnotched(fiat), and was broken by flow from a stricking pendulum. Figure 3 shown schematically the experimental arrangement. The IS of the specimen for this test can be calculated by equation ... 

As regards the toughness of plastics, the catastrophic Northridge earthquake (6.7 on the Richter Scale) on January 17,1994 can be mentioned it was found that within the three pipe materials used (asbestos cement, PVC and steel), PVC outperformed the others. In 30 minutes, while hundreds of mains and service lines broke, none of the lines made of PVC, about half of the city s total system of approximately 430 km, failed. 

Plane strain fracture toughness of plastics D4255... 

Test and service data with PVC both rate low in notched Izod impact tests and performs well in normal service applications that involve impact loading. Another example is with some grades of rubber-modified high impact PSs that show up well in the Izod test fail on impact under field test conditions. These results have led to continual reexamination of the tests used to determine the toughness of plastics. 

Increases toughness of plastics such as polycarbonate, poly-ester/polycarbonate alloys, and SAN. 

Yang, Q.D. and Thouless, M.D., Reply to comments on determining the toughness of plastically-deforming Joints, y. Mater Sci. Lett., 18, 2051-2053 (1999). 

Behavior under shock loading, which indicates the toughness of plastics, is determined by standardized methods in impact or puncture tests. Impact testers or drop testers are used to determine the work absorption capability of bar-shaped or plate-shaped test specimens, in most cases until failure or in the case of puncture tests also until initial damage occurs. The test specimens can be notched. Common test procedures include [8]... 

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