Bending radius

In this test, a rectangular strip sample is formed around a die with a precisely machined edge of a known radius. The sample is formed by 90° or 180° about an axis in the plane of the sheet. The outer surface of the bend is inspected for cracking or unacceptably deep surface mmpling for the particular appHcation. The minimum bending radius (MBR) about which strip can be successfully formed depends on the strip thickness, t, and is reported with the test thickness specified or normali2ed with regard to thickness as MBR/1. Better formabiHty is indicated by smaller MBR/1 values. 

Forming Limit Analysis. The ductihty of sheet and strip can be predicted from an analysis that produces a forming limit diagram (ELD), which defines critical plastic strains at fracture over a range of forming conditions. The ELD encompasses the simpler, but limited measures of ductihty represented by the percentage elongation from tensile tests and the minimum bend radius from bend tests. 

Fig. 8. Springback behavior for alloy C260, as defined by the ratio of the original forming angle, 90° or q, divided by the final relaxed angle, The effects of temper and orientation ate shown as a function of bending radius R, normalised by the thickness of the strip t.

Ri = bend radius of welding elbow or pipe bend, in (mm)... 

Tube O.D., In. Bend Radius, In. Center-to-Center Distance... 

Bends are described by their radius measurements. The ideal bend radius is 2 to 3 times the ID, as shown in Figure 40.27. For example, if the ID of a line is 2 inches, the radius of the bend should be between 5 and 6 inches. 

The minimum bend radius for flexible hose varies according to the size and construction of the hose and the pressure under which the system operates. Current applicable technical publications contain tables and graphs showing the minimum bend radii for the different types of installations. Bends that are too sharp will reduce the bursting pressure of flexible hose considerably below its rated valve. 

Proof stress (MPa) Tensile strength (MPa) Elongation on 50 mm (<7o) Fatigue limit (% of T.S.) Bend radius Young s modulus (GPa) Density (g/cm )... 

If U-tubes are used the number of tubes will be slightly less than that given by equation 12.3a, as the spacing between the two centre rows will be determined by the minimum allowable radius for the U-bend. The minimum bend radius will depend on the tube diameter and wall thickness. It will range from 1.5 to 3.0 times the tube outside diameter. The tighter bend radius will lead to some thinning of the tube wall. 

Draw a tube layout diagram, take minimum bend radius... 

The fact that Ac is proportional to the bending radius is used in so-called insertion devices such as wiggler and undulator magnets.t Although a description of these is beyond the scope of this chapter, the basic principle behind these is to make the electron beam undergo sharp serpentine motions (thereby having a very short radius of curvature). The net effect is to increase the flux and the critical energy (see topmost curve in Fig. 5). 

Special attention has to be given to low-loss bends, which for decreasing bend radius ask for increasing index contrast An. The minimum bend radius... 

Waveguide Material Bend Radius Waveguide size Interaction... 

This formally simple procedure is very difficult to perform, however. Because of radiation from the bend, the azimuthal propagation constant v to be found is complex. Since the bend radius of the waveguide is typically larger than the wavelength, the real part of v can be large, too. Moreover, a number of modes of each slice with very different values of their effective indexes are to be considered simultaneously. It causes very serious... 

Transfer line elbows must be designed with a gentle bend such that the bend radius is at least five times greater than the diameter of the pipe. This type of design produces a streamlined flow path without regions where the velocity is... 

While UV-vis fibers are much less prone to fiber breakage than mid-IR fibers, excessive mechanical stress may still break the fibers. The miifimum bending radius as specified by the supplier should be observed, and excessive mechanical stress should be avoided. 

Bend radius too small for the type and size of hose... 

Di, = outside diameter of branch Ri = bend radius of welding elbow or pipe bend r = see definition in para. 304.3.4(c) and Table 10-48 r2 = mean radius of matching pipe s = miter spacing at centerline... 

Figure 14.20 Intermediate cross-head locations and corresponding component shapes during forming of a component that has a constant bend radius larger than the forming rollers...

Under the action of a local shear stress, a, a straight dislocation line that is fixed at two points will bend out. The bending radius is inversely proportional to a. The dislocation becomes unstable if the bending radius is <1/2, where / is the distance between the anchor points (Fig. 3-3). Dislocation loops can be formed and macroscopic plastic deformation can continuously occur under stress if... 

Fiber Bend Radius—Radius a fiber can bend before the risk of breakage or increase in attenuation. 

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