Impact loading-rate

The cell compressive strain (Fig. 2) was maximal at the 5 %/s loading rate, and was smallest when loaded at the impact loading rate (500%/s). Fluid pressure changes in the cells (Fig. 3) increased about 50 times when loading rates were increased from 0.17 %/s to 500 %/s. 

Compressive cell strains were lowest for the highest (impact) loading rate, which was expected because of the viscoelastic properties of the tissue (Fig. 2). Nguyen et al. found that compressive cell strains of approximately 78% were required to kill chondrocytes [31], Such values were... 

It had been shown that isolated chondrocytes could be killed with hydrostatic pressures of 5-10 MPa [12, 13]. However, chondrocytes protected by the PCM could resist pressures as high as 50 MPa [13]. The highest pressures in our study were produced with the fastest (impact) loading rates, but reached only approximately 55 MPa (Fig. 3), suggesting that chondrocytes would not have been killed in our impact loading scenario. 

Zhao et al. [193] found in composites with AI2O3 nanoparticles that at quasi-static loading rate the fracture toughness was found nearly unvaried with the filler content. Under impact loading rate, the notched Izod impact strength and the impact... 

P.S. Follansbee, The Rate Dependence of Structure Evolution in Copper and its Influence on the Stress-Strain Behavior at Very High Strain Rates, in Impact Loading and Dynamic Behavior of Materials (edited by C.Y. Chiem, H.-D. Kunze, and L.W. Meyer), Springer-Verlag, New York, 1988, pp. 315-322, Vol. 1. 

API Standard 4A (superseded by Standard 4F) provides rating of derrick capacities in terms of maximum safe load. This is simply the load capacity of a single leg multiplied by four. It does not account for pipe setback, wind loads, the number of lines between the crown block and the traveling block, the location of the dead line, or vibratory and impact loads. Thus, it is recommended that the maximum safe static load of derricks designed under Standard 4A exceed the derrick load as follows ... 

The manufacturer shall establish the reduced rated static hook loads for the same conditions under which the maximum rated static hook loads apply, but with the addition of the pipe-setback and sucker-rod loadings. The reduced rated static hook loads shall be expressed as percentages of the maximum rated static hook loads. Thus, the portable mast ratings in Standard 4D include a safety factor of 2 to allow for wind and impact loads, and require the manufacturer to specify further capacity reductions due to setback. 

Extreme Low Temperature. Maximum load ratings shall be established at room temperature and shall be valid down to 0°F (-18°C). The equipment at rated loads when temperature is less than 0°F is not recommended unless provided for by the supplemental requirements. When the equipment is operating at lower temperatures, the lower impact absorbing characteristics of many steels must be considered. 

For the most part, many of the behavioral characteristics discussed are valid for a wide range of loading rates. There may be significant shifts in behavior, however, at load or strain durations that are much shorter than those discussed, usually take about a second or less to perform (Figs. 2-47 and 2-48). This section deals with loading rates significantly faster than those covered so far, namely rapid and impact loading. 

Conditions during start-up can have a dramatic impact on time required to reach reasonable performance levels and on the ultimate reactor performance. Dilution rate, loading rate as measured by chemical oxygen demand (COD), carrier choice, inoculum amount, inoculum strategy, and inoculum species distribution are critical parameters (Sreekrishnan et al., 1991 Araki and Harada, 1994 Austermann-Haun et al., 1994 Yongming et al., 1993). Pore characteristics have a strong influence on time required for start-up and on the ultimate biomass density in the... 

Fig. 7,2. Fracture toughness, R, of Kevlar 49-epoxy matrix composites (a) under varying strain rates in three-point bending and (b) at different temperatures under impact loading (O) uncoated fibers (0)41%, (Q) 63% and ( ) 100% Estapol coated fibers (A) silicone vacuum fluid (SVF) coated fibers. After Mai...

Eker S. and F. Kargi (2006). Impacts of COD and DCP loading rates on biological treatment of 2,4-dichlorophenol (DCP) containing wastewater in a perforated tubes biofihn reactor. Chemosphere 64 1609-1617. 

Table 9. Critical strain energy release rates, G ., for common thermoplastics measured under impact loading promoting brittle fracture [92]...

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