Out-of-phase loads

At variance with Eqs. (9.28), (9.31) is judged to be equally vahd also for out-of-phase loads. It is common opinion that as far as brittle materials are concerned the equivalent stress based on the maximum principal stress criterion is effective. 

Fatemi, A., Stephens, R.I. Biaxial fatigue of 1045 steel under in-phase and 90° out-of-phase loading. SAE AEXX multiaxial fatigue (1987)... 

Kanazawa, K, Miller, K.J., Brown, M.V. Low cycle fatigue under out-of-phase loading conditions. J. Engng Mater. Tech. 99, 222-228 (1977)... 

Experimentally DMTA is carried out on a small specimen of polymer held in a temperature-controlled chamber. The specimen is subjected to a sinusoidal mechanical loading (stress), which induces a corresponding extension (strain) in the material. The technique of DMTA essentially uses these measurements to evaluate a property known as the complex dynamic modulus, , which is resolved into two component parts, the storage modulus, E and the loss modulus, E . Mathematically these moduli are out of phase by an angle 5, the ratio of these moduli being defined as tan 5, Le. 

A general description of the fundamental relationships governing the dynamic response of linear viscoelastic materials may be found in several sources (28, 37, 93). In general, sinusoidally applied strains (stresses) result in sinusoidal stresses (strains) that are out of phase. Measurements may be made under uniaxial, shear, or dilational loading conditions, and the resultant complex moduli or compliance and loss-phase angle are computed. Rotating radius vectors are usually taken to represent the... 

Current and voltage may be at maximum values, but be out of phase, drawing relatively less power. As load in-... 

Frequency-domain response It is often convenient to characterize the linear response of systems in the frequency rather than in the time domain. If one applies a periodic loading with angular frequency co [circular frequency / = co/(27r)], one will obtain a periodic response of the same frequency, but the response will generally be out of phase. 

Wind loading on outdoor structures, particularly tall stacks, towers, and pipeline suspensions, require special attention. The upsetting wind moment on vertical structures must be allowed for in foundation design. Oscillations due to von Kdrmdn vortices at low, steady wind velocities can be removed by designing the equipment with a natural frequency out of phase with the frequency of the von Kdrmdn vortices that is likely to occur owing to the prevailing steady winds of that locality. 

INDUCTIVE LOADS - Loads whose voltage and current are out-of-phase. True power consumption for inductive loads is calculated by multiplying its voltage, current, and the power factor of the load. 

The distinction between a thermomechanical analyser and a dynamic mechanical analyser is blurred nowadays since many instruments can perform TMA-type experiments. The configuration of a DMA is essentially the same as the TMA shown in Figure 5 with the addition of extra electronics to apply an oscillating load and the ability to resolve the resulting specimen deformation into in-phase and out-of-phase components so as to determine E, E" and tan S. The facility for sub-ambient... 

ABSTRACT. The principle features of the frequency-response i paratus developed at Imperial College is described. The apparatus has been used in both its a) full and b) single-step frequency modes to determine the diffiisivities of various hydrocarbons in silicalite-1. Die effect of temperature and loading of sorbate in the silicalite-1 has been ascertained. The effect of the introduction of A1 atoms into the framework of silicalite-1 on the diffusivity of benzene has been detmnined. The diffusion of benzene in NaX has been studied and diffusion coefficients obtained which agree with NMR pulsed field gradient measurements, n-Butane and 2-butyne hydrocarbons were found to generate out-of-phase response curves by the full FR method which could only be fitted by introducing two diffusion coefficients into the solution of the appropriate diffusion equation. 

For the load due to differential motion of buildings, a static equivalent analysis is sufficient. When lines, pipes, conduits and so on connect two buildings, the assumption has to be made that the two buildings move out of phase. 

Fig. 2.18 By using a hybrid instead of a T connector as shown above, we can direct the signals from two subarrays into the input impedance when they are in phase and into the hybrid load Zl when out of phase. In either case (and everything in between) the hybrid input impedance at ports 2 and 3 witi be perfectiy matched and no significant backscatter will take place.

Ammeters must be connected In series with the load, and voltmeters in parallel across the load, as shown in Fig. 4.17. The power in a resistive load may be calculated from the readings of voltage and current since P = VI. TTiis will give accurate calculations on both a.c. and d.c. supplies, but when measuring the power of an a.c. circuit which contains inductance or capacitance, a wattmeter must be used because the voltage and cument will be out of phase. 

On the AC system, conventional meters can be used to determine the levels of power and power factor, and conventional tariff metering can be used to record the energy consumed over a period of time and the maximum demand. The importance of the maximum demand is discussed in Section S.3.2.4. Power factor, discussed in Section 8.3.2.3, is a measure of the extent to which a load current is out of phase with the supply voltage. 

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