Number of cycles

Figure 4 Correlation plots of load versus number of cycles for the non-filtered (up) and filtered (bottom) AE data of a test at (Tna, = 80% a and R = 0.1...

Table B3.5.1 Number of cycles to converge for geometry optimizations of some typical organic molecules usmg Cartesian, Z-matrix and delocalized internal coordinates. ...

The minimum number of cycles is given by the nullity or Frerejacque number ( ) according to Eq. (5). It is the difference between the number of nodes a = atoms) and the number of edges h = bonds). The value of 1 stands for the number of compounds considered (here, one compound). This minimum number corresponds to the munber of chords. These are defined as nodes that turn a cyclic graph or structure into an acyclic one. 

Convergence limit and Iteration limit specify th e precision of the cal-ciilation. Convergence limit refers to the dilTereiice in energy (in kcal/mol) between two successive SCE cycles. Iteration limit specifies the maximum number of cycles allowed to reach that goal. 

Total number of DNAs is 2" where n = number of cycles... 

You should terminate a geometry optimization based upon the root-mean-square gradient, because the number of cycles needed to minimize a molecule varies according to th e initial forces on the... 

Fig. 16. Maximum shear stress at bore vs number of cycles to failure for specimens of EN25 T steel at various k values. +, / = 1.2 Q = 1-4 ...

The life of a component, as measured in a fatigue test, is the number of cycles needed to initiate a crack and cause it to propagate across the wall until it intersects the outside surface or until fast fracture intervenes. 

An important descriptor of a chain reaction is the kinetic chain length, ie, the number of cycles of the propagation steps (eqs. 2 and 3) for each new radical introduced into the system. The chain length for a hydroperoxide reaction is given by equation (10) where HPE = efficiency to hydroperoxide, %, and 2/ = number of effective radicals generated per mol of hydroperoxide decomposed. For 100% radical generation efficiency, / = 1. For 90% efficiency to hydroperoxide, the minimum chain length (/ = 1) is 14. 

The practical use of photochromic dyes as memory layers in erasable and rewritable data storage disks fails not only because of their physical limitations (lacking sensitivity, insufficient stabiHty, low number of cycles), but also because the diode lasers required for switching in the visible range (wavelength between 450 and 600 nm) and the uv-range (around 350 nm) are not available. 

Machine components ate commonly subjected to loads, and hence stresses, which vary over time. The response of materials to such loading is usually examined by a fatigue test. The cylinder, loaded elastically to a level below that for plastic deformation, is rotated. Thus the axial stress at all locations on the surface alternates between a maximum tensile value and a maximum compressive value. The cylinder is rotated until fracture occurs, or until a large number of cycles is attained, eg, lO. The test is then repeated at a different maximum stress level. The results ate presented as a plot of maximum stress, C, versus number of cycles to fracture. For many steels, there is a maximum stress level below which fracture does not occur called the... 

Fatigue is another property of considerable interest to the design engineer. CycHc deflections of a predeterrnined ampHtude, short of giving immediate failure, are appHed to the specimen, and the number of cycles to failure is recorded. In addition to mechanically induced periodic stresses, fatigue failure can be studied when developing cycHc stresses by fluctuating the temperature. 

Inflated Diaphragm Method (ASTM D3886). This method is appHcable both to woven and knitted fabrics. The specimen is abraded by mbbing either unidirectionally or multidirectionally against an abradant having specified surface characteristics. The specimen is supported by an inflated mbber diaphragm under a constant pressure. Evaluation of abrasion resistance can be either by determination of the number of cycles required to wear through the center of the fabric completely or by visual examination of the specimens after a specified number of cycles. 

Rotating Beam Fatigue Test for Steel Cords. The purpose of this test method is to evaluate steel cord for pure bending fatigue (121). The test sample consists of a 3-mm diameter mbber embedded with steel cord. Different bending stress levels are appHed and the time to failure is recorded. The test stops at 1.44 million cycles. The fatigue limit is calculated from S—N (stress—number of cycles) curve. 

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