Abstract:
Embodiments of the present application generally provide for wind turbine blade spar caps comprising composite materials prepared using a low viscosity resin system and a high density fabric and methods for their manufacture. In particular embodiment, the low viscosity resin system has a viscosity in the range of about 1 to about 100 centipoises at a temperature in the range of about 0° C. to about 125° C. during the preparation of the composite material. By using low viscosity resin systems, composite materials have been prepared having a fiber volume fraction of greater than about 65% and a composite modulus of greater than 48000 MPa.
Abstract:
A method for making a turbine blade includes providing a bucket in the turbine blade with a plurality of window pockets passing all the way through a wall of the bucket, positioning the window pockets in regions minimizing or at least reducing stress concentrations on the window pockets, and casting a composite comprising a resin matrix and layers of a fabric material in the bucket.
Abstract:
Disclosed herein are dual cure compositions, methods to cure dual cure compositions, the dual cure compositions comprising at least one filler, at least one curable monomer comprising at least one of an ethylenic unit or cyclic ether unit or mixture thereof; at least one photoinitiator; and at least one thermal initiator. The method comprises the step of photocuring by exposing the compositions to radiation to at least partially photocure the composition, which in turn generates an exotherm which initiates thermal curing. The methods may be used to make cured thick compositions and sandwich structures. Articles made by the methods are also described.
Abstract:
A steam turbine blade includes a shank portion and an airfoil portion. The airfoil portion is formed with at least one pocket filled with a polymer filler material chosen as a function of natural frequency impact on the turbine blade or as a function of the damping characteristics of the filler materials. A steam turbine rotor wheel includes a plurality of blades secured about a circumferential periphery of the wheel, each blade having one or more pockets in the airfoil portion, the plurality of blades divided into two groups of blades. The pockets of one group of blades are filled with one or more polymer filler materials, and the pockets of the other group of blades filled with one or more polymer filler materials, wherein the polymer filler materials in the one group of blades creates different natural frequencies or damping characteristics in the blades of the one group than the polymer filler materials in the blades of the other group. The two groups of blades are assembled on the rotor wheel in accordance with a predetermined pattern.
Abstract:
Epoxy polymer precursors and epoxy polymers resulting therefrom are tolerant to bombardment by high-energy radiation. The epoxy polymer precursors comprise at least an epoxy resin free of aromatic units and at least a curing agent selected from the group consisting of aliphatic polyamines, cycloaliphatic polyamines, polyamides, aliphatic anhydrides, cycloaliphatic anhydrides, and mixtures thereof. In one embodiment of the invention the epoxy resin comprises at least a cycloparaffinic group, and the curing agent comprises a polyamine derived from cyclohexane. Such epoxy polymer compositions are used to form reflectors elements between adjacent scintillator elements in high-energy radiation detector array.
Abstract:
Two pieces of composite material are simultaneously joined together throughout an interface between the two pieces, by induction heating the interface region with an induction coil placed, at least in part, adjacent to the bonding region, and forcing the composite material at the interface together while heating. The approach is particularly useful in joining pieces having "long interfaces" whose longitudinal dimension is substantially larger than its transverse dimension, for example the long interfaces between aircraft wing stiffeners and skins. The induction coil is configured so that, at any one longitudinal location along the interface, the primary current flowing therethrough does not flow in opposite directions in the portions of the coil overlying the interface, and preferably flows in substantially the same direction throughout the interface. Unheated "cold spots" in the interface being bonded, which would not bond properly, are thereby avoided. An electrically nonconductive but thermally conductive material may be placed between the induction coil and the composite material pieces to act as both a heat sink and a pressure-applying tool. Bonding may be enhanced by placing a susceptor made of the same materials as the composite materials being bonded but having a higher electrical conductivity, in the interface between the two composite material pieces prior to induction heating.
Abstract:
Embodiments of the present application generally provide for wind turbine blade spar caps comprising composite materials prepared using a low viscosity resin system and a high density fabric and methods for their manufacture. In particular embodiment, the low viscosity resin system has a viscosity in the range of about 1 to about 100 centipoises at a temperature in the range of about 0° C. to about 125° C. during the preparation of the composite material. By using low viscosity resin systems, composite materials have been prepared having a fiber volume fraction of greater than about 65% and a composite modulus of greater than 48000 MPa.
Abstract:
Adhesive formulations generally including an acrylate and/or methacrylate monomer; a vinyl ester resin having a weight average molecular weight ranging from about 450 to about 3000; and a catalyst. Also disclosed is a method for forming a composite material employing the formulations.
Abstract:
An enclosure for a rotor in a generator including the rotor, rotor windings and a stator, the enclosure comprising a plurality of composite rings located adjacent one another along a length dimension of the rotor so as to contain the rotor windings on the rotor, the rings each comprising at least two layers selected from the group consisting essentially of metals, glass fiber laminates and graphite fiber laminates.
Abstract:
Adhesive formulations generally including an acrylate and/or methacrylate monomer; a vinyl ester resin having a weight average molecular weight ranging from about 450 to about 3000; and a catalyst. Also disclosed is a method for forming a composite material employing the formulations.