Composite patching

Sabelkina V, MaUa S, Hansena MA, Vandawakerb RM, Derrisob M. Investigation into cracked aluminum plate repaired with bonded composite patch. Compos Struct 2007 9(l) 55-66. 

Adhesive bonding is also usefiil for the repair of both metals and composites patches can be applied as temporary or permanent repairs to reinforce damaged stractures and bonded in place using special equipment to apply heat and pressure (see Repair methods). In these circumstances, it is not always possible to use the same pre-treatment and bonding... 

Bonded Lap joints are also used to repair cracked metal parts with composite patches. These patches serve to reduce the stress levels at the ends of cracks and to greatly extend the fife of some metal parts." ... 

Composite patch repair for metallic bridge structures... 

Composite patch repairs overcome some of the traditional disadvantages of normal rehabilitating methods used currently to upgrade bridge stmctures. These advantages are ... 

Aggelopoulos, E. S., Righiniotis.T. D. andChryssanthopoulos, M. K. (2011), Debonding of adhesively bonded composite patch repairs of cracked steel members . Composites Part B Engineering, Vol. 42, Issue 5, July 2011, pp. 1262-1270. 

Bassetti, A., Colombi, P. and Nussbaumer, A. (2000b), Finite element analysis of steel members repaired by prestressed composite patch . Proceedings of the IGF 2000, XV Congresso Nazionale del Gruppo Italiano Frattura, Bari, Italy, 3-5 May 2000. 

Colombi, R, Bassetti, A. and Nussbaumer, A. (2003), Analysis of cracked steel members reinforced by pre-stress composite patch . Fatigue and Fracture of Engineering Materials and Structures, Vol. 26, pp. 59-66. 

Anisotropic particles, such as patchy, multicompartment, and Janus particles, have attracted significant attention in recent years because of their novel morphologies and diverse potential applications. The noncentrosymmetric features of these particles make them a unique class of nano-or microcolloidal materials. Patchy particles usually have different compositional patches in the corona, whereas multicompartment particles have a multiphasic anisotropic architecture in the core domain. In contrast, Janus particles, named after the double-faced Roman god, have a strictly biphasic geometry of distinct compositions and properties in the core and/or corona. This property of Janus particles allows for distinct shape, composition, chemistry, polarity, functionality, electrical, and properties, making them suitable for applications in switchable display devices, interface... 

Fig. 2.9. Scaled active twist rotor blade with piezoelectric fiber composite patches attached to the spar fi om Cesnik [44].

Rose, J.L., Rajana, K.M. and Barshinger, J.N., Guided waves for composite patch repair of aging aircraft. Presented at Symposium on Conrposite Aircraft Repair, Vancouver, BC, 1995. 

Although natural cement was used as a restoration material as early as 1820, when Thomas Jefferson replaced leaking Mme mortars on the Monticello cisterns with natural cement, its true potential can only now begin to be imagined. Applications such as microinjection grouting and composite patching were never envisioned by the canal and fortification builders. The developments of the past 35 years in cement admixture technology have been widely applied to concrete construction and restoration, but have never been used in conjunction with natural cement. 

Fig. 12 a P3HB/at-P3HB asymmetric patches [17] (reprinted by permission of Wiley) and b P3HB film/textile composite patches (Institute of Polymer Research, Dresden, Germany) with porous surface to support tissue regeneration and smooth siu-face to prevent adherence to surrounding organs... 

Other examples of joint-end modifications for joint transverse stress reduction but using external tapers are those of Sancaktar and Nirantar (2003) and Kaye and Heller (2005). Kaye and Heller (2005) used numerical optimization techniques in order to optimize the shape of the adherends. This is especially relevant in the context of repairs using composite patches bonded to aluminum structures (see Sect. 27.5) due to the highly stressed edges. 

Soutis and Hu (1997) studied numerically and experimentally bonded composite patch repairs to repair cracked aircraft aluminum panels. The authors concluded that the bonded patch repair provides a considerable increase in the residual strength. 

Bouiadjra BB, Fekirini H, Belhouari M, Boutabout B, Serier B (2007) Fracture energy for repaired cracks with bonded composite patch having two... 

The analyses referred to above are essentially exact, but can be applied only to bonded joints between adherends of uniform thickness. A new approximate method was developed during the Composite Repair of Aircraft Structures (CRAS) R8cD contract that covers tapered adherends as well. The method, explained by Hart-Smith (2001/2002), relies on the knowledge that the adhesive stresses will be extremely low everywhere except in the immediate vicinity of changes to or interruptions in the thickness of the adherends. It starts with a closed-form analysis in which it is assumed that all the members are fused rigidly together over the entire overlap. The load sharing between the overlapped members can also account for residual stresses caused by thermal dissimilarities between adherends, as between composite patches and cracked metallic structures and between bonded titanium stepped plates at the ends and... 

Composite patches may also be used to repair metallic structures, and recent studies have indicated the potential of such repairs for naval and offshore structures (e.g., Bowditch et al. 2004 Turton et al. 2005). These may be applied, using infusion or preimpregnated materials, or adhesively bonded, and can be applied to repair fatigue cracks, corrosion damage, or for reinforcement purposes. Advantages over metallic repair are ... 

Speth DR, Yang YP, Ritter GW (2010) Qualification of adhesives for marine composite-to-steel applications. Int J Adhes Adhes 30(2) 55-62 Tamblin JS, Yang C, Harter P (2001) Investigation of thick bond line adhesive joints. DOT/FAA/AR-01/33 Turton TJ, Dalzel-Job J, Livingstone F (2005) Oil platforms, destroyers and frigates — case studies of QinetiQ s marine composite patch repairs. Compos A 36 1066-1072... 

Besides the application of FRP on RC structures, there are other researches which were focused on the application of FRP on repairing steel members. Roberts (1995) carried out experimental work to examine the behavior of crack growth retardation in steel plates reinforced with carbon fiber composite patching. Fatigue tests of... 

When composite patching is provided to the cracked surface of a steel member, the composite patching provides deformation constraint to the cracked mouth. Rose (1982) carried out an analytical study estimating the reduction of the crack extension force when a cracked plate is repaired by reinforcing patches bonded on its faces. Rose pointed out that there are two main effects of the bonded reinforcing... 

Figure 8.3 Illustration of modeling of cracked member with composite patching.

Colombi, P., Bassetti, A., Nussbaumer, A., 2003b. Delamination effects on cracked steel members reinforced by prestressed composite patch. Theoretical and Apphed Fracture... 

Naboulsi, S., Mail, S., 1996. Modeling of a cracked metallic stracture with bonded composite patch using the three layer technique. Composite Stractures 35, 295—308. 

Roberts P.D., 1995. Crack Growth Retardation by Carbon Fiber Composite Patching An Application to Steel Pressure Vessel Repair (Master of Science thesis). University of Alberta, Department of Mechanical Engineering. 

Sun, C.T., Klug, J., Arendt, C., 1996. Analysis of cracked aluminum plates repaired by bonded composite patches. AIAA Journal 34 (2), 369—374. 

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