High rate tension test

Many other important impact design parameters such as yield stress, energy to yield, initial modulus, and deformation at break can be measured with high-speed tension tests (38). In spite of the capability of high-rate tension tests to provide stress at strain rates that simulate actual service, the tests have not been popular because the delivered stress is uniaxial. Normally, the real-life impact stress is multiaxial. 

The biggest advantage of the falling-weight impact test over the pendulum impact test or high-rate tension test is its ability to duplicate the multidirectional impact stresses that a part would be subjected to in actual service. The other obvious advantage is the flexibility to use specimens of different sizes and shapes, including an actual part. Unlike the Izod impact test, which measures the notch... 

At high temperature, the behavior is different. A stmcture designed according to the principles employed for room temperature service continues to deform with time after load apphcation, even though the design data may have been based on tension tests at the temperature of interest. This deformation with time is called creep because the design stresses at which it was first recognized occurred at a relatively low rate. 

Ductile fracture dok-Cl [MF L, MF, fr. ductilis, from ducere] (14c) (ductile rupture) adj. The breaking or tearing, most commonly in tension, of a test specimen or part after considerable unrecoverable stretching (plastic strain) has occurred. Since the mode of fracture depends on conditions as well as material, the distinction between ductile and brittle fracture, which latter occurs after relatively little, recoverable strain, is not always clear. Low temperatures, especially below the glass transition (Tg), and high rates of strain favor brittle behavior, while the opposites favor ductile behavior. 

High rate stress/ strain (tension) ASTM D2289 Area under stress-strain curve measures impact resistance at testing speeds up to 254 m/min. 

Extracting solvent To achieve the required selectivity, the most adequate solvent should be chosen. The rule like dissolves like" can be a good approach. Different water-immiscible solvents with different polarity and water solubility can be tested. The solvent must satisfy some basic requirements high surface tension to form a drop, selectivity, extraction efficiency, low volatility, incidence in the drop loss, rate of drop dissolution, and solvent toxicity and its peaks should be well separated from the analyte peaks [211]. 

Figures 7-2 and 7-3 show the dispersed phase hold-up x as a function of the specific flow rate uc of the continuous phase, using various specific flow rates ud of the dispersed phase as a parameter. The experimental data shown in Fig. 7-2 is applicable to different random packing elements, such as metal Pall rings, Biatecki rings, Hiflow rings with a dimension of 25-38 mm, whereas the data shown in Fig. 7-3 is valid for 50 mm tube columns and other structured packings. The test system used for the experiments under normal conditions was toluol (D)/water, which has a high interfacial tension and is...

The equipment required for slow strain-rate testing is simply a device that permits a selection of deflection rates whilst being powerful enough to cope with the loads generated. Plain or precracked specimens in tension may be used but if the cross-section of these needs to be large or the loads high for any reason, cantilever bend specimens with the beam deflected at appropriate rates may be used. It is important to appreciate that the same deflection rate does not produce the same response in all systems and that the rate has to be chosen in relation to the particular system studied (see Section 8.1). 

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