Tensile notched specimen

As an example, the reduced size domain to calculate the stress affected distribution of diffusible hydrogen in a particular tensile notched specimen, the same as considered above, is verified as shown in fig. 5, where corresponding boundary conditions are indicated. There a mesh of linear triangular elements is employed, although, this is not a matter of particular essence with respect to the presented approach. 

The fatigue behavior of a material is normally measured in a flexural but also in a tensile mode. Specimens may be deliberately cracked or notched prior to testing, to localize fatigue damage and permit measuring the crack-propagation rate. In constant-deflection amplitude testing a specimen is... 

Generic Material Type Trademark Grade Izod Impact Energy for 0.318 cm (0.125 in.) thick, Notched Specimens, J/m Tensile-impact Short Specimens, kJ/m2 Energy Long Specimens, kJ/m2... 

Besides crystallinity itself, the kind and amount of side chains is of importance for crazing. A schematic investigation of the influence of chain branches was performed in PE that were introduced via copolymerization [84], A long-chain branched low-density polyethylene (PE-LD) was compared to a linear low-density polyethylene (PE-LLD) with different short chains [85]. Type and concentration of the copolymers were chosen in order to attain the same density of 0.920 g/cm3 and melt flow rate of 25 g/10 min for all polymers. The ESC resistance was measured in a long-term tensile test of notched specimens at 50 °C in 10% Igepal solution. 

Table 4 Time to fracture of branched PEs tested in long-term tensile tests at 50 °C in a 10% aqueous solution of Igepal (CO-630, notched specimen). Number of branches/1000 carbon atoms 18. Isothermal crystallization at 115°C/lh [85]...

The results of the ESC experiments obtained with the notched specimen in air, water and phosphoric acid solution are depicted in Fig. 3. The TTF is plotted against the nominal stress, and the dashed lines at 8 and 276 hours denote the respective saturation and the time to hydrolysis (50% chemical degradation see Material and Hydrolysis ). The time to hydrolysis and the TTF cannot be directly compared because they are the result of two totally different test methods, i.e. a tensile test and a constant-load test. However the fracture stress as a function of the exposition time shows a sharp decline around the time to hydrolysis, while there is hardly any influence at shorter exposition times. Therefore a significant influence of only hydrolysis on the TTF can only be expected around and after the time to hydrolysis. 

The notched tensile test specimens used in this investigation are shown in Fig. 1. For most tests, the notched specimens were used with a notch concentration factor of Kt — 6.3, as determined after Neuber [ ]. In one series of tests a of 15.0 was used. Each notched specimen was checked with a Jones Lamson optical comparator at 50 x. Only those specimens with notched dimensions within the specified tolerances were tested. 

From Figs. 2 and 3, it is clear that adjustment can be made to the alloy to obtain desired tensile properties and the NTS/UNTS ratios to satisfy the needs of a particular application. It is realized, of course, that the test result from a simple uniaxial tensile test of a notched specimen may not be completely valid for extending data to all applications ... 

Table 9.32 Damage propagation of aramid and E-glass fiber RPs using tensile-notched test specimen...

CTp = tensile strength for the case of eccentric tension of notched specimen (A = relative reduction in area... 

En kJ m tensile-impact strength (notched specimen) according to ISO 8256... 

Following are selected data for the most often used polymers. They have been divided (partly arbitrarily, because of the overlap in definitions) into four tables, numbered from 24.3 to 24.6 respectively, for general purpose polymers, engineering polymers, thermosets, and elastomers. The third colunm in each of these tables shows the values of density, the fourth of the tensile modulus, the fifth the stress at break, the sixth the elongation at break IS denotes the Izod impact strength for notched specimens. The letters A and C in the last column in Tables 24.3 and 24.4 pertain respectively to amorphous and crystalline thermoplastic polymers. 

Standard test methods are used to provide assurance that test data from various laboratories yield meaningful results. Therefore, test specimens must meet the requirements of ASTM E 8 for tensile specimens, ASTM E 23 for Charpy V-notch specimens, and ASTM A 370 for both tensile and Charpy specimens. Fracture toughness specimens and testing methods should meet the intent of ASTM E 399, E 1820 and E 1921. 

Fracture toughness specimens are sometimes contained in some older capsules, although the types of specimens are not always those recommended by current ASTM test methods. For example, the wedge-open loading (WOL) specimen was used in some early capsules since it is somewhat similar to the compact tensile (CT) specimen, it can be tested in a modified form to generate fracture toughness data. Converting Charpy V-notch... 

This assembly (Figure 5.3-3) contains 3 base metal (transverse) tensile test specimens and 12 impact test specimens in the top section. The tension specimens are placed in a housing machined to fit the compartment. Split spacers are placed around the gage length of the specimens to minimize the temperature differential between the specimen gage length and the coolant. The impact specimens are arranged vertically in 1 x 3 arrays and are oriented with the notch toward the reactor core. Spacers are utilized between the test specimens and the compartment. The... 

---