Charpie report

Charpy notched impact strengths in excess of 55 kJ/m have been reported for alloys with homopolymers and in excess of 20kJ/m for copolymers. 

There are other types of impact tests for shock loading where energy is required to cause complete failure is reported. Each has their specific behaviors that can be related to specific product performance requirements. Tests include ball burst, ball or falling dart using different weights and heights, bag drop, bullet-type instantaneous impact, Charpy, dart drop, Mullen burst, tear resistance, and tub (2). 

Numerous studies have been made of the mechanical properties of fibrous composites these include recently published papers on impact properties by Izod (1,2, 3,4) and Charpy (5,6) and drop weight (7) tests. We reported the Charpy impact fracture behavior of various glass-polyester composites regarding the effects of temperature (8,9,10), specimen size (8), and fiber orientation (10). This paper describes the effects of the tough-brittle transition in the impact behavior of glass-polyester composites which occurs with a variation of temperature and specimen size. 

X-65. Reference 22 reported postweld mechanical properties in 6 mm (0.25 in.) thick FSW X-65 pipe. Transverse tensile strengths were equivalent to the base metal. All tensile samples fractured in the base metal well removed from the weld or HAZ. Charpy impact results in the weld nugget and HAZ exceeded that of the base metal at -50, 0, and 20 °C (-58, 32, and 68 °F). These results are shown in Fig. 6.2. 

For polymer sheets, the notched Izod impact strength is often reported (ASTM D256). In this test, as well as the Charpy impact test in the same ASTM standard, the polymer sample is subjected to an impact from a falling hammer, and the... 

Nakamura ct al. [68] have used the instrumented Charpy test to examine the effect of silica fillers on epoxy resins, while Wang ct al. [69] have used the same technique for examining RIM parts. An examination of fillers in polypropylene has been reported by Jancar and DiBcncdetto [70]. Trantina and Ochler [71] discuss the application of Charpy (and Izod) tests to the prediction of impact resistance for use in design calculations. Sharpe... 

The impact properties of headgear materials are well reported, but commonly employ testing regimes that simplify sample shapes or inadequately represent protocols as desired for helmet materials. For example, standard Izod, Charpy, and... 

The report of the inquiry [111] criticised the design and fabrication of the alterations made to the original pontoon. The actual cause of the accident was the failure of some tie bars in the detail around the jacking points. The failure was due to brittle fracture which initiated from severe notches such as a small radius curve at the fillet between the spade end and the shank of the tie bar. Weld defects and fatigue cracks were also present in tie bars subsequently recovered from the sea bed. The tie bars had been flame cut to shape and had weld repairs visible to the eye. There had been no post welding heat treatment of the steel. The steel complied with the original specification but tests showed low Charpy V notch impact values. Photo elastic tests indicated a stress concentration factor of 7 at the fillet between the spade end and the shank. The fracture was initiated in the opinion of the inquiry tribunal by the low ambient temperature of around 3°C. 

Values and units The measured values of complete and hinged breaks can be used for a common mean value with remark. If in the case of partial breaks a value is required, it shall be assigned with the letter P. In case of nonbreaks, no figures are to be reported. (If within one sample the test specimens show different types of failures, the mean value for each failure type shall be reported.) Unnotched Charpy impact strength (kJ/m ). ... 

The Izod impact test is based on an old, established test originally designed for metals in which a notched-bar specimen is tested in cantilever fashion with an excess energy pendulum machine. Izod (ASTM D256), Charpy (ASTM D6110 and Research Report D20-1034, to become a new standard), and the tensile-impact (ASTM D1822) tests can be performed with pendulum machines. 

Charpy impact ASTM D6110 (also. Research Report D20-1034) Similar to Izod impact test. Notched specimen is supported on two ends and struck by a pendulum in the middle, a three-point-bend setting. 

Fast, P. J., Susskind, C. S., and Raymond, L., "Charpy V-Notched Specimens for Indexing Stress Corrosion Cracking in HY Ship Steels and Weld Metals, Final report under contract F04701-78-C-0079, The Aerospace Corporation, August 1979. 

The most common impact tests for plastics and metals are Izod and Charpy tests (see Figs. 3-77 and 3-78). A heavy hammer at the end of a pendulum arm swings down and strikes a cantilevered specimen (in the Izod test) or a beam specimen supported on both ends (in the Charpy test). The specimens are unnotched unless the data reports that they are to be notched for information on specimens and test procedures see ASTM D 256. 

---