Ultrasonic imaging is a powerful nondestructive evaluation (NDE) tool for flaw characterization. This thesis discusses the signal processing techniques developed for ultrasonic imaging of flaws in composite laminates. Commonly used time-domain signal processing techniques have problems including poor resolution, dependence on operator's experiences and subjectivity. Some transform-domain proces...

Many opportunities are becoming available for using composite materials to strengthen/upgrade existing reinforced concrete (RC) structures. This paper focuses on a new technique for the seismic upgrade of RC beam-column connections in gravity load-designed (GLD) frames by the application (combined or not) of FRP rods and laminates. The FRP rods provide flexural strengthening, whereas the lay-up...

Abstract. Generally one encounters a substantial variation in the mechanical properties of composite laminates. This is due to the fact that a large number of parameters have to be controlled during the manufacturing process. The dispersion in the material properties can best be accounted for by modelling these as random. In this paper, FEM in conjunction with Monte Carlo Simulation is employed...

TIlls paper describes the design and manufacture of a multifunctional space structure. The analytical techniques used in this project included thermal analyses of structures in various earth orbits, determination of structural requirements from optical performance calculations, designing of near zero Coefficient of Thermal Expansion (CTE) laminates, consideration of manufacturing and material v...

Abstract Low mechanical resistance and high weight restrict use of natural stones in applications where tensile or flexural capacity is required together with a low weight, such as for long spans or thin sections (e.g., cladding, countertops, desktops). The use of composite laminates as external reinforcement both to increase the mechanical resistance and to decrease weight of natural stone is ...

The increasing use of composite materials in many advanced structures brings with it a need to establish inspection and monitoring regimes to ensure structural integrity and safe operation throughout the service life. This results in the fast-growing composite industry searching for a technologically and economically feasible structural health-monitoring method to identify and assess defects/cr...

The relationships between a resistance curve (R-curve), the corresponding fracture process zone length, the shape of the traction/displacement softening law, and the propagation of fracture are examined in the context of the through-the-thickness fracture of composite laminates. A procedure that accounts for R-curve toughening mechanisms by superposing bilinear cohesive elements is proposed. Si...

In recent years, even if Fiber Reinforced Polymer (FRP) composites have been widely used for strengthening of civil buildings, a new generation of materials has been studied and proposed for historical masonry construction. These buildings, mainly made of stone work, are common in many areas of Europe and Asia and recent earthquakes has been the cause of many catastrophic failures. The brittlen...

Synopsis A theoretical study of viscoelastic properties of composites is presented with the aim of identifying structures which give rise to a combination of high stiffness and high loss tangent. Laminates with Voigt and Reuss structure, as well as composite materials attaining the Hashin-Shtrikman bounds on stiffness were evaluated via the correspondence principle. Similarly, viscoelastic prop...

Electrical tomography can be used as a structural health monitoring technique to identify different damage mechanisms in composite laminates. Previous work has established the link between transverse cracking density and mesoscale conductivity of the ply. Through the mesoscale relationship, the conductivity obtained from electrical tomography can be used as a measure of the transverse cracking ...