Laminated composite

Acoustic Emission to Model the Fatigue Behaviour of Quasi-Isotropic Carbon-Epoxy Laminate Composites. 

Lafarie-Frenot, M.C. and Henaff-Gardin, C., Formation and Growth of 90° Ply Fatigue Cracks in Carbon/Epoxy Laminates , Composites Science and Technology Vol. 40, p. 307-324, 1991... 

Laminates. Two or more layers of material bonded together form a laminated composite. Common examples of laminates are in automobile windshields (laminated glass) and bimetal thermostats (9). In both cases homogeneous, isotropic layers of materials are bonded together to form nonhomogeneous composite laminates (see Laminates). 

Poly(phenylene sulfide) (PPS) is another semicrystalline polymer used in the composites industry. PPS-based composites are generally processed at 330°C and subsequently cooled rapidly in order to avoid excessive crystallisation and reduced toughness. The superior fire-retardant characteristics of PPS-based composites result in appHcations where fire resistance is an important design consideration. Laminated composites based on this material have shown poor resistance to transverse impact as a result of the poor adhesion of the fibers to the semicrystalline matrix. A PPS material more recently developed by Phillips Petroleum, AVTEL, has improved fiber—matrix interfacial properties, and promises, therefore, an enhanced resistance to transverse impact (see PoLYAffiRS containing sulfur). 

Classical laminated plate tlieoiy is used to determine the stiffness of laminated composites. Details of the Kitchoff-Love hypothesis on which the theory is based can be found in standard texts (1,7,51). Essentially, the strains in each ply of the laminate ate represented as middle surface strains plus... 

Laminated composite materials that consist of layers of various materials... 

Laminated composite materials consist of layers of at least two different materials that are bonded together. Lamination is used to combine the best aspects of the constituent layers and bonding material in order to achieve a more useful material. The properties that can be emphasized by lamination are strength, stiffness, low weight, corrosion resistance, wear resistance, beauty or attractiveness, thermal insulation, acoustical insulation, etc. Such claims are best represented by the examples in the following paragraphs in which bimetals, clad metals, laminated glass, plastic-based laminates, and laminated fibrous composite materials are described. 

Find another example or type of laminated composite material than those mentioned in Chapter 1 and describe it. 

The topic of materials with different strengths and stiffnesses in tension than in compression will not be covered further in much depth (except to report different strengths) because research on such materials is still in its infancy. However, the topic is very important for the general class of composite materials, if not fiber-reinforced laminated composites. Ambartsumyan and his associates first reported research on this topic in 1965 [2-9]. A few Americans have also investigated some aspects of the mechanics of these materials (see Jones [2-10], Bert [2-11], and Bert and Reddy [2-12]). 

Laminated composite plates under in-plane tensile loading exhibit deformation response that is both like a ductile metal plate under tension and iike a metai plate that buckles. That is, a composite plate exhibits progressive faiiure on a layer-by-layer basis as in Figure 4-34. Of course, a composite plate in compression buckles in a manner similar to that of a metal plate except that the various failures in the compressive loading version of Figure 4-34 could be lamina failures or the various plate buckling events (more than one buckling load occurs). 

The existence of interlaminar stresses means that laminated composite materials can delaminate near free edges whether they be at the edge of a plate, around a hole, or at the ends of a tubular configuration used to obtain material properties. In all cases, delamination could cause premature failure so must be considered in specimen design because othen/vise the specimen does not represent the true physical situation. 

R. Byron Pipes, Jack R. Vinson, and Tsu-Wel Chou, On the Hygrothermal Response of Laminated Composite Systems, Journal of Composite Materials, April 1976, pp. 129-148. 

R. Byron Pipes and I. M. Daniel, Moir6 Analysis of the Interiaminar Shear Edge Effect in Laminated Composites, Journal of Composite Materials, April 1971, pp. 255-259. 

J. N. Reddy, Mechanics of Laminated Composite Piates Theory and Analysis, CRC Press, Boca Raton, Florida, 1997. 

Robert M. Jones and Jose C. F. Hennemann, Effect of Prebuckling Deformations on Buckling of Laminated Composite Circular Cylindrical Shells, AIM Journal, January 1980, pp. 110-115. 

M. S. Ewing, R. J. Hinger, and A. W. Leissa, On the Validity of the Reduced Bending Stiffness Method for Laminated Composite Plate Analysis, Composite Structures, Volume 9, 1988, pp. 301-317. 

Pagano studied cylindrical bending of symmetric cross-ply laminated composite plates [6-21]. Each layer is orthotropic and has principal material directions aligned with the plate axes. The plate is infinitely long in the y-direction (see Figure 6-16). When subjected to a transverse load, p(x), that is, p is independent of y, the plate deforms into a cylinder ... 

Jamea M. Wl ey, Stress Analysis of Thick Laminated Composite and Sandvrich Plates, Journal of Composite Materials, October 1972, pp. 426-440. 

Hong T. Hahn and Stephen W. Tsai, Nonlinear Elastic havior of Unidirectional Composite Laminae, Journal of Composite Materials, January 1973, pp. 102-118. 6-49 Hong T. Hahn, Nonlinear Behavior of Laminated Composites, Journal of Composite Materials, April 1973, pp. 257-271. 

DavkJ Ford Sims, Viscoelastic Creep and Relaxation Behavior of Laminated Composite Plates, Ph.O. dissertation. Department of Mechanical Engineering and Solid Mechanics Center, Institute of Technology, Southern Methodist University, Dallas, Texas, 1972. (Also available from Xerox University Microfilms as Order 72-27,298.)... 

One of the key elements in laminated composite structures design is the ability to tailor a laminate to suit the job at hand. Tailoring consists of the following steps. We want to design the constituents of the laminate, and those constituents include the basic building blocks of the individual laminae and as well how they are oriented within the laminate. We design those constituents to just barely meet (with an appropriate factor of safety) the specific requirements for, say, strength and stiffness. 

The composites have been classified in general under the following heads particulate composites, fibrous composites, and laminated composites [1]. 

In laminated composites, the individual layers of materials are bonded together to form an element or plate. When the constituent materials in each layer are the same, the laminated layers are called a laminate (e.g., plywood, papers, etc.). If the layers are of different constituent materials or of the same material with different reinforcing patterns, the laminate is said to be a hybrid laminate. 

Wadsworth, J. (2002), Ancient and modem steels and laminated composites containing steels, Mater. Research Soc. Bull. 27(12), 980-987. 

The elastic modulus of laminated composite plate in which an ER silicone gel of carbonaceous particles is sandwiched between two PVC sheets also changed under the influence of an electric field. It was found that an electric field of 1.17 kV/mm caused a gain in the elastic modulus of the gel of 13% [57]. 

Laminated composites, 26 760 Laminated glass, as a solar energy material, 23 5... 

The short beam shear test designated in ASTM D 2344 (1989) involves loading a beam fabricated from unidirectional laminate composites in three-point bending as... 

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