Struts

Cavitation Formation of transient voids or vacuum bubbles in a liquid stream passing over a surface is called cavitation. This is often encountered arouna propellers, rudders, and struts and in pumps. When these bubbles collapse on a metal surface, there is a severe impact or explosive effec t that can cause considerable mechanical damage, and corrosion can be greatly accelerated because of the destruction of protective films. Redesign or a more resistant metal is generally required to avoid this problem. 

Most ceramics are intrinsically hard ionic or covalent bonds present an enormous lattice resistance to the motion of a dislocation. Take the covalent bond first. The covalent bond is localised the electrons which form the bond are concentrated in the region between the bonded atoms they behave like little elastic struts joining the atoms (Eig. 17.1b). When a dislocation moves through the structure it must break and reform... 

Fig ure 5-22. Upstream view of the inlet casing assembly. The nose cone is supported by struts that also allow entry of cooling steam and instrumentation into the cone. 

Figure 5-24. The struts transmit thrust ioads imposed on the nose cone by fiue gases to the iniet casing and its supports.

Convection and Impingement Cooling/Strut Insert Design... 

The stresses in the strut insert are higher than those in the shell, and the stresses on the pressure side of the shell are higher than those on the suction side. Considerably more creep strain takes place toward the trailing edge than the leading edge. The creep strain distribution at the hub section is unbalanced. This unbalance can be improved by a more uniform wall temperature distribution. 

This design has a strut-supported porous shell (Figure 9-19). The shell attached to the strut is of wire from porous material. Cooling air flows up the central plenum of the strut, which is hollow with various-size metered holes on the strut surface. The metered air then passes through the porous shell. The shell material is cooled by a combination of convection and film cooling. This process is effective due to the infinite number of pores on the blade surface. The temperature distribution is shown in Figure 9-20. 

The trailing edge of the strut develops the highest creep strain. This strain occurs despite the sharp stress relaxation at the trailing edge projection. The creep strain in the strut is well balanced. Transpiration cooling requires a material of porous mesh resistant to oxidation at a temperature of 1600°F (871.1 °C) or more. Otherwise, the superior creep properties of this design... 

Similar desirability factors may be derived for other geometries such as struts, columns etc. This concept is taken further later where material costs are taken into account and Tables 1.11 and 1.12 give desirability factors for a range of loading configurations and materials. 

Show that the critical buckling strain in a strut with pinned ends is dependent only on the geometry of the strut. 

Linnecessary noise, these should be cleaned regularly. Imbalance, whether due to dirt or to other causes, should be corrected by adjustment. Detective bearings should be adjusted or replaced. Struts and sharp edges in front of an impeller should be avoided. Impact noise insulation should be introduced between fan room and floor structure and between fan room and connecting ducts. The fan unit should be enclosed, with satisfactory airborne sound insulation as the objective. 

MERWMG8KM - LEX ACCESS COVER - AVIOMBS ACCESS OOORS NLO STRUT DOOR DRAG BRACE FAIRMO... 

There are at least two ways to make the struts. They could be solid members, or they could be hollow members. You could well imagine that, under certain circumstances, solid members would be perhaps preferable to hollow members, and for other reasons just the opposite would be true. It is up to you to figure out which of those two choices is best for this application. Look at both choices, or you can, alternatively, give a compelling argument as to which configuration, solid cross section, or hollow cross section, you use, with an emphasis on why. Then, you will not have to do the other calculations. 

Steife, /. stiffening (starch, glue, size) consistency prop, strut, stay stiffness, rigidity, steifen, v.t. stiffen starch stay, prop. Steifheit,/. stiffness, rigidity. 

The history of the technical development of the airplane can be divided into four eras pre-Wright the strut-and-wire biplane the mature propeller-driven airplane, and the jet-propelled airplane. We will organize our discussion in this article around these four eras. 

The Wright Flyer ushered in the era of strut-and-wire biplanes, and it basically set the pattern for subsequent airplane design during this era. The famous World War I fighter airplanes—such as the French Nieuport 17 and the SPADXIII, the German Fokker... 

Space frames are structures made up of nodes and struts. When the struts that connect the nodes together are slender, the axial stiffness of the strut becomes the dominant form of stiffness, and the bending stiffness that might be achieved in the attachment of a strut to a node is usually very much smaller, and can often be ignored. 

A strut is usually viewed as a single degree of freedom constraint. It has a length, and that is its key dehning property. A stmt or column or beam can connect between two nodes, thus dehning the distance between those points. An interesting and important variant of a stmt is a cable. This component can only take tension loads, and cannot carry compressive loads. 

In a stmcture N denotes the number of nodes and S the number of struts. 

The simplest determinate 3-d structure has 4 nodes and 6 struts "SN — 6 = 6 and is a tetrahedron. It is straightforward to make 3-d structures that are over or under determined (Table 2). 

In examining 3-d structures, it is clear that each node must be connected by at least three struts. When a node is connected within a structure by only three struts, it can be removed (along with its three struts) without changing the determinate nature of the remaining structure. 

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