METHOD FOR OPTIMIZING THE MASS OF A COMPOSITE PANEL

• US 20090022945A1
• Filed: 07/20/2007
• Published: 01/22/2009
• Est. Priority Date: 07/20/2007
• Status: Active Grant

• Current Assignee: Airbus Operations SAS (Airbus SE)
• Original Assignee: Airbus France
• Inventors: Carpentier, Alban, Grihon, Stephane
• Granted Patent: US 8,181,345 B2
• Time in Patent Office: Days
• US Class Current: 428/119
• CPC Class Codes: B32B 2605/18 Aircraft
• CPC Class Codes: B32B 5/024 Woven fabric
• CPC Class Codes: B32B 5/12 characterised by the relative arrangement of fibres or filaments of different layers, e.g. the fibres or filaments being parallel or perpendicular to each other
• CPC Class Codes: G06F 2111/06 Multi-objective optimisation, e.g. Pareto optimisation using simulated annealing [SA], ant colony algorithms or genetic algorithms [GA]
• CPC Class Codes: G06F 2113/24 Sheet material
• CPC Class Codes: G06F 30/3323 using formal methods, e.g. equivalence checking or property checking
• CPC Class Codes: Y10T 29/4932 Turbomachine making
• CPC Class Codes: Y10T 29/49616 Structural member making
• CPC Class Codes: Y10T 29/49622 Vehicular structural member making
• CPC Class Codes: Y10T 29/49801 Shaping fiber or fibered material
• CPC Class Codes: Y10T 428/24174 including sheet or component perpendicular to plane of web or sheet

Abstract

A method for optimizing the mass of a composite panel. The panel is composed of a plurality of uniform thickness zones, each zone defined by a vertical arrangement of plies having different orientation angles. The arrangement defined by a determined number of plies, a positioning order of the plies having a given orientation angle with respect to the others in the vertical arrangement, and the proportion of plies having a given orientation angle with respect to all the plies composing the vertical arrangement. The optimization includes defining a lay-up table. Defining a vertical arrangement of plies for each uniform thickness zone. Starting from the lay-up table, a function describing the physical properties of each zone of the composite panel is built, as a function of the total thickness of each zone, the total thickness for each zone is adjusted using a discrete variables iteration process, the aim of the process being reached when the mass of the panel is minimum.

Claims

1. A method for optimizing the mass of a composite panel, the said panel being composed of a plurality of uniform thickness zones, each uniform thickness zone being defined by a vertical arrangement of plies having different orientation angles, the said arrangement being defined by a determined number of plies, a positioning order of the plies having a given orientation angle with respect to the others in the vertical arrangement, and the proportion of plies having a given orientation angle with respect to all the plies composing the vertical arrangement, characterized in that the said optimization method includes the following main steps:

a) a lay-up table is defined, the said table defining a vertical arrangement of the plies for each uniform thickness zone,

b) starting from the said lay-up table, a function describing the physical properties of each zone of the composite panel is built, as a function of the total thickness of each zone, the total thickness for each zone is adjusted using a discrete variables iteration process, the aim of the process being reached when the mass of the panel is minimum.

2. A method according to claim 1, characterized in that step a) for defining the lay-up table includes a preliminary step for building the table wherein idealistic proportions of plies having a given orientation angle with respect to the total thickness are determined for each uniform thickness zone of the panel using a discrete variables iteration process, so as to minimize the total mass of the panel.

3. A method according to claim 2, characterized in that upon completion of the said preliminary step a function giving the proportion of plies having a given orientation angle as a function of the total thickness is defined for each uniform thickness zone and the optimum total thickness is determined using a discrete variables iteration process, so as to minimize the total mass of the panel.

4. A method according to claim 3, characterized in that the derivative of the said function is positive so as to impart ply continuity between two adjacent uniform thickness zones.

5. A method according to claim 1, characterized in that, prior to performing step b) the positioning order of the plies having a given orientation angle different from the others in the arrangement for each uniform thickness zone is adjusted using a discrete variables iteration process, the aim of the process being reached when the buckling resistance corresponds to a predefined threshold value.

6. A method according to claim 1, characterized in that for performing step b) of the method, the lay-up table of step a) is a pre-existing lay-up table.

7. A method according to claim 1, characterized in that upon completion of step b), the exact number of plies for each uniform thickness zone of the panel is determined using a discrete variables iteration process, the aim of the process being reached when the mass of the panel is minimum.

8. A method according to claim 1, characterized in that all the plies composing the vertical arrangement have the same thickness.

9. A method according to claim 1, characterized in that the said composite panel is a plane or curved panel.

10. A method according to claim 1, characterized in that the plies are unidirectional pre-impregnated plies.

11. A method according to claim 1, characterized in that the plies are woven plies.

12. Stiffened composite panel produced from the optimal vertical arrangement of plies for each thickness zone upon completion of the optimization method according to claim 1.

13. Use of the said composite panel according to claim 12 as an equipment for an aircraft.