Dynamic stress test

C under the Dynamic Stress Test for EVs in accordance with the United States Advanced Battery Consortium Procedure 5B. This has a variable discharge profile based on specific power requirements, with a maximum of 150 Wkg when related to a full-sized EV battery. For the experimental cells, the peak power was equivalent to a current density of 16.3mAcm . ... 

Table 5.5. Utilization of negative active-material under Dynamic Stress Test.

The capacities and utilizations obtained under the variable power Dynamic Stress Test at 25°C and — 18°C followed a similar trend. The results for materials which gave good utilizations are summarized in Table 5.5. 

Many consortia and publications have proposed a number of standard drives to evaluate battery performance. Schedules such as the Federal Urban Drive Schedule (FUDS), the Highway Fuel Economy Test (HWFET), and the Dynamic Stress Test (DST) are used as yardsticks of performance on a comparative basis. As metrics for fuel economy or other corporate standards, they may be appropriate but these should not generally be used as the real-world test of battery performance. Where performance is to be measured, it is recommended here that a Kochis Stress Test (KST) be used, which is a test philosophy that states that the maximum loads (charge and discharge) that will be used in the vehicle should be used to establish performance traits. This implies two points (i) the test should be demonstrated and calibrated in a vehicle that is the intended application (ii) if vehicle calibrations are changed, the effect on battery performance must be re-evaluated. 

Design Failure Modes and Effects Analysis double layer capacitor depth-of-discharge dynamic stress test... 

Testing the negative electrode of a lead-acid battery includes the following tests [48] (1) cycle life test, (2) capacity test, (3) charge rate acceptance test, (4) storage test, (5) overcharge test, and (6) dynamic stress test. Brief descriptions of the testing processes for some of the main tests follow ... 

FIGURE 37.1 Typical cycle of dynamic stress test for electric-vehicle batteries. From Ref. 2.)... 

The end of fife, as typically defined for electric-vehicle batteries, is a 20% loss of capacity on a standard simulated vehicle driving profile. A commonly used profile is the simplified federal urban driving schedule (SFUDS). Bipolar 13-cm diameter Li-Al/FeS2 cells obtained over 300 eycles on a modified version of the SFUDS, denoted the Dynamic Stress Test (DST). Both the FeS and U.P. FeS2 chemistries have demonstrated the ability to achieve more than 1000 cycles in fiooded-electrolyte prismatic cells when discharged at constant current." As is tme for other high-temperature batteries, cycle life is not likely to be strongly influenced by cycle type. 

Rheometric Scientific markets several devices designed for characterizing viscoelastic fluids. These instmments measure the response of a Hquid to sinusoidal oscillatory motion to determine dynamic viscosity as well as storage and loss moduH. The Rheometric Scientific line includes a fluids spectrometer (RFS-II), a dynamic spectrometer (RDS-7700 series II), and a mechanical spectrometer (RMS-800). The fluids spectrometer is designed for fairly low viscosity materials. The dynamic spectrometer can be used to test soHds, melts, and Hquids at frequencies from 10 to 500 rad/s and as a function of strain ampHtude and temperature. It is a stripped down version of the extremely versatile mechanical spectrometer, which is both a dynamic viscometer and a dynamic mechanical testing device. The RMS-800 can carry out measurements under rotational shear, oscillatory shear, torsional motion, and tension compression, as well as normal stress measurements. Step strain, creep, and creep recovery modes are also available. It is used on a wide range of materials, including adhesives, pastes, mbber, and plastics. 

New types of anodes have been developed and tested as shown in Fig. 16-5 to improve the possibility of maintenance and repair. They can be lifted onto a ship and repaired. The connecting cables are also replaceable. In shallow water, the anchorage must be accurately calculated because considerable dynamic stressing can occur in heavy seas. The ocean floor must be suitable for long-term anchorage. No supply ships must anchor in the area around the platform. This requirement alone often prevents the installation of impressed current anodes since the operator does not wish or is not able to restrict himself to these conditions. 

The simplest dynamic system to analyse is one in which the stress and strain are changing in a sinusoidal fashion. Fortunately this is probably the most common type of loading which occurs in practice and it is also the basic deformation mode used in dynamic mechanical testing of plastics. 

In both mechanical and electrical testing, the frequency of dynamic stress application can be increased, although heating effects and time for relaxation processes have to be considered. For some products it is appropriate to simply use them more often, for example where in service the use is intermittent or there is normally downtime. 

Framework of load compensator on plane wings injection moulding of carbon fibre reinforced PEEK replaces the aluminium alloy previously used. This part plays a critical role in plane safety and must resist the static and dynamic stresses and hydraulic fluids. The grade selected after many tests has a high fluidity allowing the manufacture of parts with dimensions of 200 mm by 400 mm. With 30% carbon fibre reinforcement, this PEEK grade ... 

Having performed the yield stress test, each category is then divided into static or dynamic methods. Dynamic methods indicate an actual flow test of a certain type, whereas the static methods indicate tests such as rotational flow between two cylinders. 

The static tests considered in Chapter 8 treat the rubber as being essentially an elastic, or rather high elastic, material whereas it is in fact viscoelastic and, hence, its response to dynamic stressing is a combination of an elastic response and a viscous response and energy is lost in each cycle. This behaviour can be conveniently envisaged by a simple empirical model of a spring and dashpot in parallel (Voigt-Kelvin model). 

Since dynamic mechanical tests measure the response of a material to an applied stress at different temperature and frequency, they measure the transition of the material from glassy to leathery to rubbery state. If the frequency is kept constant and low (about one cycle/sec), the results are related to measurements of transition by other techniques. Thus, some cross-checking is possible. 

Dynamic Mechanical Testing - Film properties such as impact resistance and the cure response of thermosetting resins are conveniently investigated by dynamic measurements in which an oscillatory or torsional strain is applied to the sample with the stress and phase difference between the applied strain and measured stress being determined. In the present study, a Rheovibron Viscoelastometer was used which employed a sinusoidal strain at a... 

The four variables in dynamic oscillatory tests are strain amplitude (or stress amplitude in the case of controlled stress dynamic rheometers), frequency, temperature and time (Gunasekaran and Ak, 2002). Dynamic oscillatory tests can thus take the form of a strain (or stress) amplitude sweep (frequency and temperature held constant), a frequency sweep (strain or stress amplitude and temperature held constant), a temperature sweep (strain or stress amplitude and frequency held constant), or a time sweep (strain or stress amplitude, temperature and frequency held constant). A strain or stress amplitude sweep is normally carried out first to determine the limit of linear viscoelastic behavior. In processing data from both static and dynamic tests it is always necessary to check that measurements were made in the linear region. This is done by calculating viscoelastic properties from the experimental data and determining whether or not they are independent of the magnitude of applied stresses and strains. 

Detected rotational H2 and ro-vibrational CO, CO2, C2H2, HCN, as well as H2O and OH lines trace hot gas in the inner, planet-forming disk zone with T > 300 K (Brittain et al. 2003 Lahuis et al. 2006 Salyk et al. 2008), see Fig. 4.3. These lines are a good measure of temperature and high-energy radiation fields, and presumably sensitive to disk accretion, which could be a stress-test for advanced chemo-dynamical models. In Table 4.1 the various molecules used to study protoplanetary disks are overviewed. 

ANALYSIS - SCALING LAWS COMPUTER CODES - BLAST SUPPRESSION DYNAMIC STRESS ANALYSIS - STRUCTURES FABRICATION AND TESTING COST EFFECTIVENESS ANALYSIS ENGINEERING SUPPORT... 

Dynamic properties tests on viscoelastic materials fall into the general categories of resonance tests and non-resonance tests (1). They can be further subdivided into tests using base motion excitation (2), (3) and direct force excitation (4), (5). Still another classification may be made according to whether the specimen is stressed in extension, shear, or dilatation. An important issue in the selection of test methods is whether it will... 

In Figure 21.8, a softening temperature for the polystyrene endblock is shown as a function of endblock molecular weight (ranging from about 6000 to 30000). The softening temperature is characterized as the onset of test specimen creep (in a small-strain dynamic mechanical test in tensile mode), the creep point occurring when strain extension becomes considerable in order to maintain the appropriate stress level to continue the test. This softening temperature lies below the measured Tg, and it is an indication of the... 

In addition, other measurement techniques in the linear viscoelastic range, such as stress relaxation, as well as static tests that determine the modulus are also useful to characterize gels. For food applications, tests that deal with failure, such as the dynamic stress/strain sweep to detect the critical properties at structure failure, the torsional gelometer, and the vane yield stress test that encompasses both small and large strains are very useful. 

Chapter 3. In-plant measurement of flow behavior of fluid Foods. Using a vane-in-a-cup as a concentric cylinder system. The vane yield stress test can be used to obtain data at small- and large-deformations. Critical stress/strain from the non-linear range of a dynamic test. Relationships among rheological parameters. First normal stress difference and its prediction. 

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