Composites pipes

Polyester Shear strength of 20-mm-wide composite pipe section (MPa)... 

Xia M., Takayanagi H., Kemmochi K., Analysis of multi-layered fdament-wound composite pipes under internal pressure. Composite Structures 53 (2001) 483-491... 

In Japan, several commercial projects have been reported in the literature. For example, at the National Research Institute for Metals, the NiTi shape-memory alloy is produced by combustion synthesis from elemental powder for use as wires, tubes, and sheets. The mechanical properties and the shape-memory effect of the wires are similar to those produced conventionally (Kaieda et ai, 1990b). Also, the production of metal-ceramic composite pipes from the centrifugal-thermite process has been reported (Odawara, 1990 see also Section III,C,1). 

Odawara, O., and Ikeuchi, J., Ceramic composite pipes produced by a centrifugal-exothermic process. J. Am. Ceram. Soc., 69, C80 (1986). 

Polyester PC is used in various procast and cast-in-place applications in construction works, public and commercial buildings, for the manufacture of sanitary engineering, cladding of composite pipes in bathrooms and toilets, stairs, and chemical-resistant floors [2,6,7],... 

In a pipe system carrying water with some salt dissolved, a section of a polymeric composite pipe is inserted between a pipe of stainless steel and a pipe... 

Figure 7.12 Cavitation damage to a section of composite pipe flange...

O Saetre, Testing of composite pipes in high velocity seawater , 10th International OMAE Conference, Stavanger, 1991, Volume IIIB, p 577. 

The use of logarithmic extrapolation methods offers an excellent method of predicting the long term service length of composite pipe. This is similar to the extrapolation shown in the underground fuel tanks testing. 

Peck, J., Pang, S.S., Li, G., Jones, R., and Smith, B. (2007) Effect of UV-cured FRP joint thickness on coupled composite pipes. Composite Structures, 80, 290-297. 

A test room of 3 m x 5 m with an internal height of 2.8 m was furnished with vertical PVC, polyethylene, and glass fibre-reinforced polyester pipes of 25 to 90 mm dia., empty or water-filled. Some of them were covered with black-plaster wall. In a second experiment, pipes were mounted horizontally on the walls or under the ceiling. Exhaust conduits of 150 mm dia. were also incorporated, either of glass-fibre-reinforced polyester or PVC/glass-fibre-reinforced polyester composite. Pipes on the wall and the exhaust conduits were loaded with water and air streams, respectively, while the pipes under the ceiling were empty. 

Cold-setting reactions of these kinds are embodied in numerous patented dental cements (Section 12.14), electrical cements, refractory mortars, moulding compositions, pipe-jointing materials and miscellaneous industrial cements. 

Figure 13.5 These PPSF hot water fittings, designed by Wavin for use with cross-hnked polyethylene-aluminum-cross-linked polyethylene composite pipe, are used in both household plumbing and radiator heating...

Polypropylene/continuous glass fiber composite pipes design principles... 

If a thermoplastic composite pipe is pressurized rmder laboratory conditions (with the pipe ends freely moving) the stress/strain in the two principal, axial (ej and hoop ( y), directions exhibit a behavior schematically illustrated in Figure 1. Three aspects of this response, namely (1) the initial stiffness of the pipe associated with the slopes and Sy (2) nonlinearity in the cr/e response and (3) the ultimate failure of the pipe corresponding to the burst pressure, are rationalized by means of micro- and macromechanical modelling. These types of modelling of the short term structural response are the initial steps in the overall design procedure. 

A thermoplastic composite pipe produced by the tape winding process consists of two building blocks the mandrel (wall thickness t , internal radius r ) and the load-bearing composite tape (thickness f ) wound under a winding angle a with respect to the axial direction of the pipe and restraining the mandrel (Figure 2). The extruded mandrel is based on one constituent only, i.e. a viscoelastic polymer of the stress/strain response described by ct = f A, B, C, e). The three parameters are relatable to the initial stiffness and the coordinates of the yield point. The... 

Figure 1 Schematic representation of the stress/strain response of a thermoplastic composite pipe.

Using the polypropylene (PP) glass composite pipe of internal radius 55 mm and based on 3.6 mm thick mandrel overwoimd by 0.4 mm thick laminae to form +57/-57 angle-plied construction as an example, the stiffnesses associated with this structure are = 2.17 GPa, Ey = 4.34 GPa, = 2.26 GPa and = 0.37. Furthermore, it can be shown that... 

The need to partition the stress is associated with the fact that due to the presence of fibers, the stress exerted on the matrix, both in the mandrel and the composite tape, is lower than CTc associated with the internal pressure in the composite pipe. The partition factor is proposed to be the simple ratio of the relevant stiffness, thus in our case = o-c/a = Ey(Ef )/E where Ey (Ej ) is the hoop stiffness of the pipe when the matrix modulus is E. This implies that the composite pipe during pressurization finds itself in different states = 1,2. .. n, each state governed by E ( ) and associated with a specific set of the lamina characteristics, pipe stiffnesses and, consequently, stress partition factors... 

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