Loading frequency

The SPATE technique is based on measurement of the thermoelastic effect. Within the elastic range, a body subjected to tensile or compressive stresses experiences a reversible conversion between mechanical and thermal energy. Provided adiabatic conditions are maintained, the relationship between the reversible temperature change and the corresponding change in the sum of the principal stresses is linear and indipendent of the load frequency. 

The thermographic activity on the pressure vessel was carried out considering a part of it because of the axial symmetry. Three different partially overlapping area were inspected since it was optically impossible to scan the curved surface of the pressure vessel by a single sweep. The selected areas are shown in fig.7 and the correspondent positions of the thermographic scan unit are also illustrated. The tests were performed with a load frequency of 2, 5 and 10 Hz. 

The pressure amplitudes inside the vessel, the load frequencies and the relevant figures displaying the thermographic results for each scan area are listed in table 2. 

Figure 4.48 Load frequency distribution for the foot pedal...

Table 4.12 Analysis of load frequency data and plotting positions for the 2-parameter Weibull distribution...

Figure 4.49 Linear regression for the 2-parameter Weibull transformed load frequency data...

Comparison of the calculated 2-parameter Weibuii distribution with the original load frequency... 

Provision of a means of starting the motor, taking into account the requirements of torque, acceleration, load, frequency of operation and safety ... 

Young s moduli were determined in tensile tests using samples of 4 mm thickness. Slow cyclic loading (frequency 0.01 Hz) with small strain amplitudes (s < 3%) was used for the tests in order to maintain the thermal equilibrium as much as possible. The temperature range was limited to 260 °C as thermal decomposition became noticeable above this temperature [11],... 

LOAD FREQUENCY/PRECENTS FROM FREQS DATA SET TO THE PROPER PLACE IN THE VALUES ARRAY. values) sum)(lbnrind = "L") 1,(lbnrind = "N") 2,... 

Geometry and configuration Signal driver (load, frequency, etc.)... 

The complex modulus components E and E" (or G and G" or their compliance counterparts), are functions of the loading frequency or angular frequency co. To try to identify these functions, it is usual to determine E and E" experimentally in a wide interval of temperature and frequency and to build E" = f(E ) (Cole-Cole) plots. 

Figure 7. Strain amplification A plot of the strain amplification ratio er as a function of the load frequency for different load magnitudes. Strain amplification ratio is defined as the ratio of the hoop strain in the cell process membrane to the bone surface strain at the osteonal lumen, e is the strain on the whole bone s is the load on the whole bone. Previously published in You et al. (2001).

Figure 3. Solute concentration profiles at t = 87000 for different loading frequencies and dispersion parameters (a) small solute, (b) large solute.

Figure 6.45 Fatigue life data, S-N curves, for a high-strength steel under different environmental conditions. Stress ratio R — — 7. Loading frequency 7 Hz for tests in 0.6 M NaCIsolution. Horizontal arrows indicate failure condition not attained. OCP = open-circuit potential102...

Stresses. The main mechanical properties to consider are maximum stress or stress intensity factor, <7m ix or Kmax, cyclic stress or stress-intensity range, Act or AK, stress ratio R, cyclic loading frequency, cyclic load waveform (constant-amplitude loading), load interactions in variable-amplitude loading, state of stress, residual stress, and crack size and shape, and their relation to component size geometry.31... 

Cyclic load frequency is the most important factor that influences corrosion fatigue for most material environment and stress intensity conditions. The dominance of frequency is related directly to the time dependence of the mass transport and chemical reaction steps involved for brittle cracking. 

Stresses stress intensity range, load frequency and stress ratio... 

Fig. 6.5 Cyclic stress-strain behavior observed during the room temperature fatigue of unidirectional SiQ/LAS-II at a maximum stress below the 105 fatigue limit (loading frequency = 10 Hz, crmin/crmax = 0.1). The cyclic stress-strain curves show very limited, if any, hysteresis. Note that the strength and strain capability is retained after cyclic loading below the proportional limit stress. After Prewo.42...

A coincidence between the proportional limit, fatigue limit, o-fi, has also been observed for other composite systems fatigued at loading frequencies of 10 Hz or lower. For example, as shown in Fig. 6.6, under tension-tension fatigue at 1000°C, 0° SCS-6 SiQ/HPSN43 composites exhibit a fatigue limit (5 x 106 cycles) at the monotonic proportional limit stress of 200 MPa. 

Fig. 6.12 Influence of loading frequency on the surface temperature rise measured during the tension-tension fatigue of a woven 0790° CVI Q/SiC composite. The fatigue experiments were conducted at 20°C between fixed stress limits of 10 MPa and 250 MPa. After Holmes and Shuler.51...

On the other hand, very high temperatures and low cyclic loading frequencies (high cycle times) promote near-tip creep-fatigue conditions where... 

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