Polymer matrix composite repair
AssigneeROLLS-ROYCE plc
InventorsAlexis Lambourne, Alexander C. Smith, Jameel B. Khan
Life of this patent
Estimating the term…
Abstract
A procedure for repairing a polymer matrix composite component is provided. The procedure includes the steps of: providing a polymer matrix composite component having a site prepared for repair by removal of damaged or defective material; locating an uncured, polymer matrix composite repair patch at the site to re-build the component thereat; and curing the polymer matrix of the repair patch by heating the patch using eddy currents induced by one or more alternating current coils. The repair patch is without metallic additives, such that the repaired polymer matrix composite after the curing step is also without metallic additives in the vicinity of the repair patch.
Claims13
A procedure for repairing a polymer matrix composite component, the procedure comprising:
- providing a polymer matrix composite component having a site prepared for repair by removal of damaged or defective material;
- locating an uncured, polymer matrix composite repair patch at the site to re-build the component thereat;
- and
- curing the polymer matrix of the repair patch by heating the patch using eddy currents induced by one or more alternating current coils, including a process of determining a desired maximum temperature of the patch and a desired penetration depth of the electromagnetic field produced by the one or more alternating current coils, and using said desired maximum temperature and said desired penetration depth to determine corresponding values of amp-turns and frequency which are then applied to the, or each, coil in the curing process;
- wherein the repair patch is without metallic additives, such that the repaired polymer matrix composite after the curing step is also without metallic additives in the vicinity of the repair patch.
A method of determining values for amp-turns and frequency of an alternating current to be applied to an alternating current coil used for induction heating of a polymer matrix composite repair patch, the method comprising:
- (i) providing geometric properties of the patch, geometric properties of the coil, electrical properties of the patch, and thermal properties of the patch;
- (ii) determining a desired maximum temperature of the patch and a desired penetration depth of the electromagnetic field of the alternating current coil;
- (iii) estimating values for the amp-turns and frequency of the alternating current to be applied to a coil:
- (iv) using the provided geometric properties of the patch and the coil, the provided electrical properties, and the estimated values for the amp-turns and frequency to predict an eddy current density distribution in the patch and a corresponding penetration depth of the electromagnetic field produced by the coil,
- (v) using the predicted eddy current density distribution, the provided geometric properties of the patch, and the provided thermal properties of the patch to predict the maximum temperature of the patch, and
- (vi) repeating steps (iii) to (v) for different estimated values for the amp-turns and frequency of the alternating current until the predicted penetration depth and the predicted maximum temperature converge on the desired maximum temperature of the patch and a desired penetration depth of the electromagnetic field.
Dependencies are inferred from the claim text.