Casing buckling resistance

Buckling resistance The load exerted on the casing if under compression... 

For these structures, R may be taken as a value of 3, however, additional instructions apply in these cases. If huckUng of the support is determined to be the governing mode of failure, or if the structure is in Risk Category IV, then the seismic response coefficient must be determined using a value of VR =1.0 and checked against the critical buckling resistance (safety factor equal to 1.0). 

The compression under which collapse of the films occurs is very variable. In the case of palmitic acid the buckling point occurred between 20 and 45 dynes per centimetre, when the experiments were carried out with fresh water. On the other hand when water with a Ph of about 6 was used, the film, after being allowed to stand for a few days either covered or open to the atmosphere, resisted compression to over 60 dynes per centimetre. 

The external case of the rocket motor supports the mechanically and thermally induced stresses, which are due to internal gas pressure, vibration, acceleration, thrust vector control, and differential thermal expansion of component materials. To accommodate these factors, the structural material should have high strength, adequate modulus, and resistance to buckling. Either a continuous glass filament wound epoxy plastic or a high temperature metal (steel, titanium, or aluminum) case serves as the exterior structural member. 

The primary structural role of the face/core interface in sandwich construction is to transfer transverse shear stresses between faces and core. This condition stabilizes the faces against rupture or buckling away ftom the core. It also carries loads normally applied to the panel surface. They resist transverse shear and normal compressive and tensile stress resultants. For the most part, the faces and core that contain all plastics can be connected during a wet lay-up molding or, thereafter, by adhesive bonding. In some special cases, such as in a truss-core pipe. 

The column web thickness-to-depth ratio, tcw/Tc influences the column flange rotation. The column web stiffness, when an idealization of the column cross section is made, as shown in Fig. 4, is proportional to the ratio, (tcw) /Tc. The greater the column web stiffness, the greater the torsional resistance provided to restrain column flange rotation, 6c, and beam lateral-torsional buckling. In the case of the W14 x 283... 

For the case of a straight-sided buckle, the ratio of the delamination driving force G a) to the phase-angle-dependent delamination resistance r( / ) was shown in Figure 5.7 for a particular choice of the parameter r/c introduced in (5.20) and for three values of the system parameter f/m/ric-A similar representation could be produced for the case of a circular buckle. 

Class 4 - In this class, the slender cross-section, the maximum moment is governed by local buckling and occurs at a value less than the elastic moment of resistance. In this case the stress at the extreme fibres reach the yield strength./ [Pg.595]

The measurement technique of texture of porous materials that collapse under isostatic mercury pressure is based on the mechanical behavior of the network of interconnected filaments. This method defines, as characteristic size, the length of the edge ofthe reference cubic pore that has the same resistance toward buckling that the true pore that collapses under mercury pressure. The calibration of this technique by other characterization methods is necessary, but results can differ depending on whether the adjustment has been made from nitrogen adsorption-desorption isotherms, or from mercury intrusion porosimelry. In the case of discrepancy, preference is given to this last adjustment method. 

Each casing head consists of two hemispheres with the inner hemisphere dimpled at numerous points and spot-welded to the outer hemisphere. The dimples are deep enough to develop an effective flexural rigidity to resist buckling. 

Thouless et al. derived a model based on buckling of an edge flake that predicted n=3. An indentation fracture mechanics model by Chai and Lawn for edge chip resistance is also consistent with the power law eq, 2, but only for the case of /r = 1.5. Although some of our data matched the power law with rr = 1.5, much of it did not. Exponents ranged from as small as 1 to as large as 2. Problems remain with the interpretation of the exponent n and the constant A. Is /r a fundamental material parameter indicative of a material s chipping behavior Can it be related to other material properties What are the units of A ... 

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