Charpy impact energy

Figure 10.6. (a) Indentation nanohardness of silver/chromium multilayers and single films of the constituent metals, as a function of depth affected by plastic deformation, (b) Charpy impact energies, a measure of fracture toughness, of three materials, as a function of test temperature they are mild steel, ultrahigh-carbon steel and a composite of the two kinds of steel (courtesy Dr. J. Wadsworth) (Fig. 10.6(b) is from Kum et at. (1983)). 

The Izod and Charpy impact tests are mostly used. A defined pendulum strikes the specimen sample, notched or un-notched, clamped with a defined device. The absorbed energy is calculated and expressed ... 

Charpy impact test—a destructive test of impact resistance, consisting of placing the specimen in a horizontal position between two supports then striking the specimen with a pendulum striker swung from a fixed height. The magnitude of the blow is increased until specimen breaks. The result is expressed in in-lb or ft-lb of energy-... 

On reaction of oxypropylated EGG with molten MDI (stoichiometric ratio, r = 1.01) at 50 °C for 5 minutes followed by curing at 90 °C for 14 hours, a transparent, amber, glassy polyurethane resin was obtained. The T of the resin by DSC was 57 °C, and its mechanical properties (23 °C) were similar to poly(methyl methacrylate) with a Young s modulus of 2.78 GPa, tensile strength of 46.3 MPa, ultimate elongation of 2.6%, and Charpy impact energy of 1.5 kJ-m-2. 

NUMERICAL DETERMINATION OF THE ENERGY CALIBRATION FUNCTION go FOR HIGH RATE CHARPY IMPACT TESTS... 

Instrumented Charpy impact tests on unnotched samples are conducted to determine the energy absorbing capability and dynamic fracture behaviour of the C/SiC composites. The dynamic fracture toughness (ak) is calculated using the following equation ... 

Temperature strongly influences the impact behavior of toughened plastics. Charpy impact energy measurements at different temperatures in the case of HIPS containing various concentrations of PBD showed two transitions, at 233 and 273 K [Bucknall, 1988]. At these temperatures, the material exhibited transitions from brittle to semi-ductile and then to ductile. 

Variation of the energy absorbed in a Charpy impact test with the radius of the notch tip in 3 mm thick bars (from Ogorkiewicz, R. M., Ed, Thermoplastics—Properties and Design, Wiley, 1974). 

Fig. 3. Fe-12Mn-0.2Ti. The furnace cooling curve and Charpy impact energy measured at -196°C. After soaking treatment (1100°C/2 hr), specimens were furnace cooled and then air cooled (1 ft-lb = 0.735 J).

Figure 8 The impact energy with the fiber volume fraction (Charpy impact test)...

To determine the Charpy impact strength of an unnotched specimen acu> the energy absorbed by breaking the specimen is related to the initial cross-section area of the specimen ... 

Notched Charpy impact strength acN is calculated from the absorbed energy W, related to the smallest initial cross-section of the specimen at notch base ... 

Charpy impact strength - data Polymer Solids and Polymer Melts B. Langer, W. Grellmann Table 4.8 Charpy impact strength values (unnotched and notched) of unfilled materials (number in brackets represents the hammer energy used). ... 

VI. 12. Examples of the use of the NDTT approach of Method 2 include the British Standards Institution s BS 5500 [VI.3], the ASME Sections III [VI.4] and VIII [VI.5] and the RCC-M Appendix ZG of the Erench Nuclear Construction Code [V1.6]. These methods address, for example, ferritic steels, for which there are substantial databases relating impact energy (Charpy testing) to fracture toughness. In such cases, the Charpy impact energy can be used as an indirect indicator of material... 

FIGURE 24.2. Length LVmm of the cracks in PE pipes determined by the Greig-Smith test 50 vs. the reciprocai Charpy impact energy (U/J) after [48]. 

Standard test methods for the determination of Charpy impact strength are Usted in Table 10.11. For example, BS 2782 (Method 351A) uses a rectangular, notched or unnotched, bar supported at both ends in such a position that the pendulum strikes it in the center, directly behind the notch. The energy absorbed in the impact is read directly by means of a pointer from a scale calibrated to allow for frictional and windage errors. Three standard test pieces are defined - the preferred being 120 x 15 x 10 mm with a span of 70 mm. The standard impact energies are 0.5, 1,4, 15, and 50 J. 

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