Pressure loads

These values were ehosen since they were the best compromise between the possibility to provtde significant amplitudes of the cyclical pressure loading and the experimental apparatus limits. Infact, the cyclical pressure amplitude gets lower as the frequency gets higher. 

Expansion joints for free-movement systems can be designed for axial or offset movement alone, or for combined axial and offset movements (see Fig. 10-171). For offset movement alone, the end load due to pressure and weight can be transferred across the joint by tie rods or structural members (see Fig. 10-172). For axial or combined movements, anchors must be provided to absorb the imbalanced pressure load and force bellows to deflect. 

Grady, D.E., Phase Transformation Under Intense Shock Pressure Loading, Sandia National Laboratories Report No. SAND82-1317C, Albuquerque, NM, 5 pp., 1982. 

OTI594 The prediction of the pressure loading on stmctures resulting from an explosion... 

Recommended monitoring for each type of pump is essentially the same, regardless of specific design or manufacturer. However, process variables such as flow, pressure, load, etc. must be taken into account. 

Since a buried pipe movement is resisted by the surrounding soil, a tensile load is produced within the pipe. The internal longitudinal pressure load in the pipe is independent of the length of the pipe. Thus, Poisson s effect must be considered when designing any length of pipe, whether long or short that is part of a buried pipe system. Buried pipes are influenced by friction with their surrounding media. 

Fig. 8-17 Example of pressure loading on the plastic melt during IM.

This section has been primarily concerned with the response of structural elements to which the blast pressure loading has been directly applied. This is termed primary (local) response to blast loading, and it is commonly... 

The principal stresses (see Section 13.3.1) acting at a point in the wall of a vessel, due to a pressure load, are shown in Figure 13.1. If the wall is thin, the radial stress comparison with the other stresses, and the longitudinal and circumferential stresses o and <72 can be taken as constant over the wall thickness. In a thick wall, the magnitude of the radial stress will be significant, and the circumferential stress will vary across the wall. The majority of the vessels used in the chemical and allied industries are classified as thin-walled vessels. Thick-walled vessels are used for high pressures, and are discussed in Section 13.15. 

The bending moments per unit length due to the pressure load are related to the slope and deflection by ... 

A general equation for the thickness of a flat plate required to resist a given pressure load can be written in the form ... 

Though secondary stresses do not affect the bursting strength of the vessel, they are an important consideration when the vessel is subject to repeated pressure loading. If local yielding has occurred, residual stress will remain when the pressure load is removed, and repeated pressure cycling can lead to fatigue failure. 

The third principal stress, that in the radial direction or3, will usually be negligible for thin-walled vessels (see Section 13.1.1). As an approximation it can be taken as equal to one-half the pressure loading... 

The tube-plates (tube-sheets) in shell and tube heat exchangers support the tubes, and separate the shell and tube side fluids (see Chapter 12). One side is subject to the shell-side pressure and the other the tube-side pressure. The plates must be designed to support the maximum differential pressure that is likely to occur. Radial and tangential bending stresses will be induced in the plate by the pressure load and, for fixed-head exchangers, by the load due to the differential expansion of the shell and tubes. 

Design procedures for tube-plates are given in BS PD 5500, and in the TEMA heat exchanger standards (see Chapter 12). The tube-plate must be thick enough to resist the bending and shear stresses caused by the pressure load and any differential expansion of the shell and tubes. The minimum plate thickness to resist bending can be estimated using an equation of similar form to that for plate end closures (Section 13.5.3). 

The fluid in a rotating centrifuge exerts pressure on the walls of the bowl or basket. The minimum wall thickness required to contain this pressure load can be determined in a... 

Covering the ablator with CMC, e.g. C/SiC, avoids the ablator erosion process. At the same time the ablator cools the CMC down to a range which is not detrimental to it. The analyses conducted up to now clearly show that even significantly higher heat and dynamic pressure loads can be coped with. 

The ideal side-on parameters almost never represent the actual pressure loading applied to structures or targets following an explosion. So a number of other properties are defined to either more closely approximate real blast loads or to provide upper limits for such loads. (The processes of reflection and diffraction will be discussed later.) Properties of free-field blast waves other than side-on pressure which can be important in structural loading ares... 

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