FRP Structures

Signature Recognition of Acoustic Emission from FRP Structures. 

The unsaturated polyester-styrene combination, is used as the resin matrix, in Fibre-reinforced plastics (FRP) structures. These resins also find use as decorative coatings. 

Corrosion resistant FRP structures and also resin linings have resin or resin-rich surface layer to protect the structures from corrosive attack. Therefore, the study of corrosion behavior of resin is essentially important. 

The combination of an adhesive and adherend is a laminate. Commercial laminates are produced on a large scale with wood as the adherend and phenolic, urea, epoxy, resorcinol, or polyester resins as the adhesives. Many wood laminates are called plywood. Laminates of paper or textile include items under the trade names of Formica and Micarta. Laminates of phenolic, nylon, or silicone resins with cotton, asbestos, paper, or glass textile are used as mechanical, electrical, and general purpose structural materials. Composites of fibrous glass, mat or sheet, and epoxy or polyester resins are widely employed as reinforced plastic (FRP) structures. 

The principle of dual laminate construction is to line an FRP vessel or column with a fluoropolymer lining. However, the sequence of construction is to first make the liner out of fabric-backed sheets the same as in the adhesively bonded construction. The FRP structure is then laminated on the liner to pro-... 

Corrosion-Resistant Binder for Fiberglass Composites. A second application of furan resins is as a premium, corrosion-resistant binder for fiberglass for fabrication of FRP structures for the chemical process industry. Structures can be easily fabricated using "hand lay-up" techniques used to fabricate polyester composites (see Figure 4). In this fashion, pipes, ducts, tanks, scrubbers, etc., are produced for use with process media which quickly... 

Hiibler, M., Gurka, M., Schmeer, S., Brener, U.P., 2013. Performance range of SMA actuator wires and SMA—FRP structure in terms of manufacturing, modelling and actuation. Smart Materials and Structures 22 (9) (lOP Publishing Ltd). 

Castro San Roman, J. (2005) System ductility and redundancy of FRP structures with ductile adhesively-bonded joints. PhD thesis. EPFL, Lausanne. 

Keller, T., Zhou, A., Tracy, C., Hugi, E., and Schnewlin, P. (2005) Experimental study on the concept of liquid cooling for improving fire resistance of FRP structures for construction. Composites Part A, 36 (11), 1569-1580. 

A one-dimensional thermal response model was developed to predict the temperature of FRP structural members subjected to fire. Complex boundary conditions can be considered in this model, including prescribed temperature or heat flow, as well as heat convection and/or radiation. The progressive changes of thermophysical properties including decomposition degree, density, thermal conductivity, and specific heat capacity can be obtained in space and time domains using this model. Complex processes such as endothermic decomposition, mass loss, and delatnina-tion effects can be described on the basis of an effective material properties over the whole fire duration. 

In multiple-story load-bearing FRP structures, passive protection methods appear appropriate to resist the passage of flames and hot gases from one space to another (structural integrity) and to maintain a temperature on the surface below specified limits (insulation). To delay stractural collapse for the code-specified 90min (structural adequacy), however, either a thickprotective layer of passive protection or an active protection method is required as well. Overall, no passive or active method is without weaknesses or compromises. For this reason, a combination of methods is usually employed. The proper combination depends strongly on the application. 

Full scale experiments on FRP structural members subjected to realistic fire exposure are also necessary. Not only does this supply valuable results and provide confidence for the fire performance of FRP structural members to be used in civil engineering, it also validates the above modeling concepts on the structural level. Similarly, as performed in the fire design of structures made by traditional materials such as steel and reinforced concrete, active and passive fire protection techniques may be necessary for prolonging resistance time of composite materials in fire. Such techniques are reviewed and compared, particularly with regard to their applications for composite materials. 

Vinyl ester resins derived from bisphenol-A epoxies are suitable for chemical resistant FRP structures, filament winding and pultrusion with failure elongations of about 6%. 

Under the effect of blast, FRP structures and components can undergo appreciable elastic distortion without suffering major permanent damage. 

P(3) When the FRP structure to be repaired may have been exposed to conditions in which it may have absorbed more humidity than under typical in doors atmospheric conditions, the structure shall be dried prior to bonding. 

Published literature in this area is very limited. One study (reference 5.37) examined structural testing of different types of bonded connections (for detailed discussion see 5.3.5.10). One of the main conclusions to emerge from this study was that weakest link in FRP structures is at the secondary bonding connections. Because of this, (pure) bonded... 

Fiber-Reinforced Plastic (FRP) Structural composite consisting of a fibrous support material encased in a solid matrix of polymerized resin. 

Common uses of FRP structures include simple fabrications such as tub and shower enclosures, spas and hot tubs, automobile body and marine patching compounds, customized and regular replacement automobile body components, and low-tolerance or low-performance shrouds and housings. Production methods for such structural composites in low-tech applications are relatively simple they do not caU for critical placement of reinforcing materials or extensive consolidation of the structure before the curing process. Similar, but fer more demanding methods are used for the production of advanced FRP structures that must meet close tolerances and high performance specifications. 

Fabrics. Structural composites in fabrics are used in an entirely different manner from other structural composites, because fabrics are typically used on their own strengths and merit rather than in combination with a binding or matrix material. Fabric composites may employ combinations of very specialized materials, especially if they are to be used in FRP applications. The vast majority of fabric structural composites, such as rayon-cotton or cotton-polyester, are used in the garment and furniture industries for clothing and for protective enclosures and coverings. Specialized fabrics combining such materials as carbon and Kevlar fibers are used in FRP structural composites. 

Bank, Lawrence G. Composites for Construction. Structural Design withFRPMaterials. Hoboken, N.J. John WUey Sons, 2006. A textbook for the application of FRP structural composites in the construction industry for new construction, retrofitting, and repairs. 

As with the structural shapes of first-generation profiles (see Section 9.8.1), which mimic the geometry of structural steel cross-sections, so the current practice of bolting FRP structural elements copies the constructive details of steel construction (Fig. 9.4). In most cases, this direct knowledge transfer of connection technology leads to oversized FRP components, since it does not consider the different behavioms of the two materials. In fact, the linear-elastic behaviour of FRP profiles is incompatible with plastic deformations and so the stress concentrations aronnd the bolt holes are higher than those... 

Pickett A K and Hollaway L (1985), The analysis of elastic-plastic adhesive stress in bonded lap joints in FRP structures . Compos Struct, 4(2), 135-160. 

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