Pressure hull structures

OPERATING depth v 20.000 FT MAXIMUM SPEED = S KNOTS ENDURANCE 30 HOURS AT 3 KNOTS 

PERCENT OF OCEAN LESS THAN INDICATED DEPTH 

This review concerns the structural behavior of filament wound RP cylinders. Test specimens of thick-walled, unstiffened cylinders with the 

The simplest method of reducing shearing and bending stresses is to use an unstiffened cylinder. Development of lower density, hollow fiber. 

Calculations indicate that a cylinder with a W/D ratio of 0.44 and made of carbon-filament-RPs with an effective RP modulus of 0.1 MPa (15 X 10 psi) would not require a stiffening system. With this W/D ratio an unstiffened cylinder of semi-infinite length would have an elastic buckling depth exceeding 21,300 m (70,000 ft). At a depth of 12,200 m (40,000 ft) a RP stress of 690 MPa (100,000 psi) would be developed. Present problems with high-modulus, carbon-fiber RPs have been the inability of laminates to take high-compressive stresses. 

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Information on underwater hulls is reviewed in Chapter 7 Filament Windings, Pressure Hull Structures. 

Table 1 gives the results of structural materials calculation activity of NPP and pressure hull of Victor 11 Submarine. 

TABLE 1. Induced Activity of NPP Structural Materials and NS Pressure Hull in 3-Years Dwell... 

A simple close-packed hexagonal structure has been reported for cerium at ambient temperature and pressure (Hull, 1921) and above 5 GPa pressure and 298 K (MeWhan, 1970). The former probably had observed the dhep 8-Ce phase along with fee y-Ce in an impure cerium sample and incorrectly indexed the non-cubic phase as simple hep. The high pressure X-ray pattern observed by MeWhan was also indexed by Ellinger and Zachariasen (1974) to be orthorhombic (see section 2.2). 

RPs have already been used in different structural applications, to replace conventional metal in seawater-compressed air surfacing ballast tanks in the Alvin depth vehicle. This vehicle, a first-generation deep research vehicle, also used RP in its outer hull construction to enclose the pressure tanks and aluminum frame. In the unmanned acoustical research vehicle of the Ordnance Research Laboratory called Divar, an RP cylinder with a 16 in. OD, 3/4 in. wall thickness, I2V2 in. ID with nine ribs, a 60 in. length and weight of 180 pounds went to depths of 950 m (6,500 ft.). 

Common uses for polyester resins are reinforced plastics automotive parts boat hulls foams encapsulation of electrical equipment protective coatings ducts flues and other structural applications low pressure laminates magnetic tapes piping bottles non-woven disposable filters and low-temperature mortars. 

Boat hulls were among the earliest applications of modern reinforced plastics. The United States Navy introduced their first 8.5 m (28 foot) fibreglass personnel boat in 1947, and was contracted to pass 3000 vessels by 1966. The orders for the first two vessels specified construction by the pressure bag method and by the vacuum injection system in order to achieve higher quality than was obtained by the then current hand-lay-up technique [1]. One of the earliest large GRP structures for submerged... 

The earliest investigations of the crystal structure of cerium (Hull, 1921) indicated that cerium had both a face centered cubic (fee) and a hexagonal close-packed (hep with cl a = 1.62) structure at room temperature and one atmosphere. Subsequent studies revealed only the fee phase with a ==5.15 A, which today is identified as y-Ce (see table 4.2 for additional crystallographic data). About 25 years ago the a-Ce phase was identified by X-ray methods at both high pressure and room temperature (Lawson and Tang, 1949) and at low temperature and atmospheric pressure (Schuck and Sturdivant, 1950) to have a fee structure but with a = 4.83 A. The a phase, with a volume about 17% less than that of y-Ce, is also known as the collapsed fee phase. This large volume difference is also observed in dilatometric and volumetric studies of the a y transformation. 

Epoxy resins Structural components, boat hulls, chemical engineering plant, pressure vessels, aerospace structural components, helicopter blades and racing cars [74]... 

Hull S, Berastegui P (1998) High-pressure structural behavior of silver(I) fluoride. J Phys Cond Matter 10 7945-7956... 

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