[SIZE=+2]CONTENTS[/SIZE]
[SIZE=+2]1. Nomenclature[/SIZE][SIZE=+2]2. Fabrication of Coupled Box-Beams[/SIZE][SIZE=+2]3. Performance of Quasi-Unbalanced Box-Beams[/SIZE][SIZE=+2]4. Configurational Considerations[/SIZE][SIZE=+2]5. Application Considerations[/SIZE][SIZE=+2]5. Specific Applications[/SIZE][SIZE=+2]7. Combined Techniques
8. Summary[/SIZE]
[SIZE=+1]A smart textile composite is a structure tailored to exhibit a desirable elastic deformation behavior not necessarily proportional to the imposed load. An example of such a structure would be a box-beam so tailored that an imposed cantilever load results in twisting as well as bending, although no torsional load was imposed. Reversible behavior would be exhibited if in addition an imposed torsional load results in bending as well as twisting, although no cantilever load was imposed. Such a structure is said to exhibit twist-bend coupling. The composite fabrication technique required to produce such a complex response can be either intrinsically-smart (passive) or extrinsically-smart (active):[/SIZE]
[SIZE=+1]Intrinsically-Smart (Passive)[/SIZE] [SIZE=+1]The symmetry and balance of the composite filament plies controls the elastic deformation response to loading of the composite[/SIZE][SIZE=+1]structure.[/SIZE] [SIZE=+1]Extrinsically-Smart (Active)[/SIZE] [SIZE=+1]The sequence of actuation of piezoelectric or magnetostrictive actuators[/SIZE][SIZE=+1]embedded between the composite plies controls the elastic deformation response to loading of the composite structure.[/SIZE] [SIZE=+1]The effect of combining these diverse techniques is discussed.[/SIZE]
[SIZE=+2]1. Nomenclature[/SIZE]
[SIZE=+1]The winding sequence of continuous-wound intrinsically-smart box-beams is denoted by balance and symmetry. A winding is denoted symmetric when the fiber orientation does not change with a 180° rotation of the beam and denoted balanced when the sum of the plies oriented at any angle from the longitudinal axis of the beam is equal to the number of plies oriented at an equal angle but in the opposite direction, taking into account the windings on both the top and bottom surfaces. Balance is required for fabrication by continuous-filament winding.[/SIZE]
[SIZE=+1]Figure 1A illustrates a conventionally-wound box-beam, which is both symmetric and balanced. Because the windings have opposite angles on opposite sides of the beam, the preferential bending axis is normal to the longitudinal axis of the beam.[/SIZE]
[SIZE=+2]
[/SIZE]
[SIZE=+2]Figure 1. Balanced and Unbalanced Winding Architecture[/SIZE]
[SIZE=+1]Figure 1B illustrates a non-symmetrical, unbalanced box-beam. Because the winding angles are the same on opposite sides of the beam, the preferential bending axis is essentially the winding angle. Hence on bending this beam will exhibit twist-bend coupling. Non-symmetry is required for coupling. The flexural behavior of the balanced (uncoupled) and unbalanced (coupled) architecture are shown in Figures 2U and 2C, respectively.[/SIZE]
[SIZE=+2]
[/SIZE]
[SIZE=+2]Figure 2. Elastic behavior of Uncoupled (U) and Coupled (C) Box-Beams[/SIZE]
[SIZE=+1]Coupling is measured analytically as the incremental change in twist angle with bend angle, as shown in Figure 3. The beam is shown twisting upwards with upwards bending, indicating divergent coupling.[/SIZE]
[SIZE=+2]
[/SIZE]
[SIZE=+2]Figure 3. Coupling Convention[/SIZE]
[SIZE=+2]1. Nomenclature[/SIZE][SIZE=+2]2. Fabrication of Coupled Box-Beams[/SIZE][SIZE=+2]3. Performance of Quasi-Unbalanced Box-Beams[/SIZE][SIZE=+2]4. Configurational Considerations[/SIZE][SIZE=+2]5. Application Considerations[/SIZE][SIZE=+2]5. Specific Applications[/SIZE][SIZE=+2]7. Combined Techniques
8. Summary[/SIZE]
[SIZE=+1]A smart textile composite is a structure tailored to exhibit a desirable elastic deformation behavior not necessarily proportional to the imposed load. An example of such a structure would be a box-beam so tailored that an imposed cantilever load results in twisting as well as bending, although no torsional load was imposed. Reversible behavior would be exhibited if in addition an imposed torsional load results in bending as well as twisting, although no cantilever load was imposed. Such a structure is said to exhibit twist-bend coupling. The composite fabrication technique required to produce such a complex response can be either intrinsically-smart (passive) or extrinsically-smart (active):[/SIZE]
[SIZE=+1]Intrinsically-Smart (Passive)[/SIZE] [SIZE=+1]The symmetry and balance of the composite filament plies controls the elastic deformation response to loading of the composite[/SIZE][SIZE=+1]structure.[/SIZE] [SIZE=+1]Extrinsically-Smart (Active)[/SIZE] [SIZE=+1]The sequence of actuation of piezoelectric or magnetostrictive actuators[/SIZE][SIZE=+1]embedded between the composite plies controls the elastic deformation response to loading of the composite structure.[/SIZE] [SIZE=+1]The effect of combining these diverse techniques is discussed.[/SIZE]
[SIZE=+2]1. Nomenclature[/SIZE]
[SIZE=+1]The winding sequence of continuous-wound intrinsically-smart box-beams is denoted by balance and symmetry. A winding is denoted symmetric when the fiber orientation does not change with a 180° rotation of the beam and denoted balanced when the sum of the plies oriented at any angle from the longitudinal axis of the beam is equal to the number of plies oriented at an equal angle but in the opposite direction, taking into account the windings on both the top and bottom surfaces. Balance is required for fabrication by continuous-filament winding.[/SIZE]
[SIZE=+1]Figure 1A illustrates a conventionally-wound box-beam, which is both symmetric and balanced. Because the windings have opposite angles on opposite sides of the beam, the preferential bending axis is normal to the longitudinal axis of the beam.[/SIZE]
[SIZE=+2].[/SIZE]
[SIZE=+2]
[SIZE=+2]Figure 1. Balanced and Unbalanced Winding Architecture[/SIZE]
[SIZE=+1]Figure 1B illustrates a non-symmetrical, unbalanced box-beam. Because the winding angles are the same on opposite sides of the beam, the preferential bending axis is essentially the winding angle. Hence on bending this beam will exhibit twist-bend coupling. Non-symmetry is required for coupling. The flexural behavior of the balanced (uncoupled) and unbalanced (coupled) architecture are shown in Figures 2U and 2C, respectively.[/SIZE]
[SIZE=+2].[/SIZE]
[SIZE=+2]
[SIZE=+2]Figure 2. Elastic behavior of Uncoupled (U) and Coupled (C) Box-Beams[/SIZE]
[SIZE=+1]Coupling is measured analytically as the incremental change in twist angle with bend angle, as shown in Figure 3. The beam is shown twisting upwards with upwards bending, indicating divergent coupling.[/SIZE]
[SIZE=+2].[/SIZE]
[SIZE=+2]
[SIZE=+2]Figure 3. Coupling Convention[/SIZE]
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