Aeroelastic instabilities are an important factor in the design of modern high-speed, flexible aircraft. The current trend is toward the creative use of composites to delay these instabilities. To obtain an optimum design, an accurate as well as efficient model is required. As a first step towards this goal, aeroelastic analysis is carried out for a swept composite box beam, using a linear stru...

In the present study, fuzzy control of vibration of a hybrid smart composite beam actuated by electro-rheological fluids (ERF) and piezoceramics actuators is investigated. A carbon fiber reinforced plastics (CFRP) cantilevered beam containing ERF with bonded piezoceramics is prepared and vibrated forcibly with sinusoidal external excitation. Fuzzy model of controlled element containing two actu...

Commercially available CdSe/ZnS and PbSe colloidal semiconductor quantum dots were employed to produce both an electron beam sensitive poly methyl methacrylate PMMA -quantum-dot QD positive composite via a prepolymerization processing and an electron beam and ultraviolet UV light sensitive SU-8-QD negative composite via a direct dispersion procedure. Compared to the QDs in the original colloida...

This paper deals with a dynamical inverse problem for a composite beam formed by two connected beams. The vibrations of the composite beam are governed by a differential system where a coupling takes place between longitudinal and bending motions. In this paper, we neglect bending motions and we only deal with the longitudinal motions. These motions are governed by a two-by-two second order sys...

This paper describes investigations into Direction–Of– Arrival (DOA) estimation of a wideband signal by a two– dimensional array antenna, which employs only spatial signal processing for beam forming. The elements of this array are arranged in a horizontal rectangular lattice to steer a beam in azimuth over a wide frequency band. By applying the concept of interpolated array, a composite covari...

The present study concerns compressive and flexural constitutive models incorporated into an isoparametric beam finite element scheme for fiber reinforced polymer (FRP) and concrete composites, using their multi-axial constitutive behavior. The constitutive behavior of concrete was treated in triaxial stress states as an orthotropic hypoelasticity-based formulation to determine the confinement ...

The bond between glass fibre framework and veneer composite can be achieved by silane coupling agents or by monomers that penetrate into a polymer network. However, it has been clinically demonstrated that his bond can fail. This study investigated whether electron beam irradiation improved the bond strength of fibre-frameworks and veneer composite with and without additional coupling agents.

Fiber reinforced polymeric composites can be employed for the construction of structures that are highly durable and easy to fabricate. At EMPA, a prototype footbridge with girders and deck made of pultruded composite sections has been designed and constructed. For thin-wall pultruded sections such as I-beam or T-beam, delaminations can form easily at the web/flange junction. If the delaminatio...

This paper describes a new material, polyurethane-cement composite (PUC), used to strengthen a 29-year-old reinforced T-beam bridge in Harbin, China. Polyurethane-cement composite (PUC) is mixed with polyurethane raw material and cement. This technique is completed by pouring Polyurethane-cement composite (PUC) into the template. Ultimate bearing capacity of the bridge after reinforcement was d...

Wave propagation in composite structures with shunted piezoelectric patches is investigated in this work. The Wave Finite Element(WFE) approach is firstly developed as a prediction tool for wave propagation characteristics like dispersion curves in composite structures, and subsequently extended to consider shunted piezoelectric elements through the Diffusion Matrix Model(DMM). A three-layered ...