Joint between airfoil and shroud

1. A vane and shroud for a gas turbine engine having a center axis, comprising:

a shroud having a radial wall facing substantially radially with respect to the center axis, a slot wall defining a slot in the shroud, a relief wall defining a relief area of the slot and wherein the relief wall extends between the radial wall and the slot wall;

a vane having an airfoil and a lug extending into the slot;

a flowable attachment material disposed in the relief area for engagement of the vane to the shroud;

said lug merges into a transition section which curves circumferentially inwardly from said lug to said airfoil; and

said radial wall is generally radially aligned with a radial extent of said transition section which is most adjacent to said radial wall.

2. The vane and shroud according to claim 1 , wherein said slot is larger than said lug, such that said flowable attachment material is also disposed between said lug and said slot wall.

3. The vane and shroud according to claim 1 , wherein said relief area has a triangular cross-section.

4. The vane and shroud according to claim 1 , wherein said relief area has a curved cross-section.

5. The vane and shroud according to claim 1 , wherein said relief area has a rectangular cross-section.

6. A vane and shroud for a gas turbine engine having a center axis, comprising:

a shroud having a radial wall facing substantially radially with respect to the center axis, a slot wall defining a slot in the shroud, a relief wall defining a relief area of the slot and wherein the relief wall extends between the radial wall and the slot wall;

a vane having an airfoil and a lug extending into the slot;

a flowable attachment material disposed in the relief area for engagement of the vane to the shroud; and

a depth of the relief wall is defined to a point most radially distant from a surface of said radial wall facing said center axis, and a radial wall thickness is defined for said shroud adjacent to said relief area, and a ratio of said depth to said radial wall thickness being between about 0.2 and 0.6.

7. The vane and shroud according to claim 6 , wherein said lug merges into a transition section which curves circumferentially inwardly from said lug to said airfoil.

8. The vane and shroud according to claim 7 , wherein said radial wall is generally radially aligned with a radial extent of said transition section which is most adjacent to said radial wall.

9. A vane assembly for use in a gas turbine engine comprising:

a circumferentially extending outer shroud and a circumferentially extending inner shroud centered on a center axis, and a plurality of vanes positioned radially between said inner and outer shrouds, a joint between said vanes and at least one of said inner and outer shrouds, said at least one said shroud having a radial wall facing substantially radially with respect to the center axis, a plurality of slots in said at least one said shroud, slot walls defining said slots in said at least one said shroud, a relief wall defining a relief area of said slots and wherein the relief wall extends between the radial wall and the slot wall;

said vanes having an airfoil and a lug extending into one of the slots;

a flowable attachment material disposed in the relief area for engagement of the vane to at least one of the inner and outer shrouds;

said jug merging into a transition section which curves circumferentially from said lug to said airfoil; and

said radial wall being generally radially aligned with a radial extent of said transition section which is most adjacent to said radial wall.

10. The vane assembly according to claim 9 , wherein said slot is larger than said lug, such that said flowable attachment material is also disposed between said lug and said wall.

11. The vane assembly according to claim 9 , wherein said relief area has a triangular cross-section.

12. The vane assembly according to claim 9 , wherein said relief area has a curved cross-section.

13. The vane assembly according to claim 9 , wherein said relief area has a rectangular cross-section.

14. The vane assembly according to claim 9 , wherein said at least one said shroud is said outer shroud.

15. A vane assembly for sue in a gas turbine engine comprising:

a circumferentially extending outer shroud and a circumferentially extending inner shroud centered on a center axis, and a plurality of vanes positioned radially between said inner and outer shrouds, a joint between said vanes and at least one of said inner and outer shrouds, said at least one said shroud having a radial wall facing substantially radially with respect to the center axis, a plurality of slots in said at least one said shroud, slot walls defining said slots in said at least one said shroud, a relief wall defining a relief area of said slots and wherein the relief wall extends between the radial wall and the slow wall;

said vanes having an airfoil and a lug extending into one of the slots;

a flowable attachment material disposed in the relief area for engagement of the vane to at least one of the inner and outer shrouds; and

a depth of the relief area is defined to a point most radially distant from a surface of said radial wall facing said center axis, and a radial wall thickness is defined for said shroud adjacent to said relief area, and a ratio of said depth to said radial wall thickness being between about 0.2 and 0.6.

16. The vane assembly according to claim 15 , wherein said lug merges into a transition section which curves circumferentially from said lug to said airfoil.

17. The vane assembly according to claim 15 , wherein said radial wall is generally radially aligned with a radial extent of said transition section which is most adjacent to said radial wall.

18. A gas turbine engine comprising:

a compressor section, a combustor section and a turbine section, with said compressor section and said turbine section being defined by a plurality of rotor stages and a plurality of vane assemblies positioned between adjacent ones of said rotor stages;

at least one of said vane assemblies having a circumferentially extending outer shroud and a circumferentially extending inner shroud centered on a center axis, and a plurality of vanes positioned radially between said inner and outer shrouds, a joint between said vanes and at least one of said inner and outer shrouds such that said at least one said shroud having a radial wall facing substantially radially with respect to the center axis, a plurality of slots in said at least one said shroud, slot walls defining said slots in said at least one said shroud, a relief wall defining a relief area of said slots and wherein the relief wall extends between the radial wall and the slot wall;

said vanes having an airfoil and a lug extending into one of the slots;

a flowable attachment material disposed in the relief area for engagement of the vane to at least one of the inner and outer shrouds; and

a depth of the relief area is defined to a point most radially distant from a surface of said radial wall facing said center axis, and a radial wall thickness is defined for said shroud adjacent to said relief area, and a ratio of said depth to said radial wall thickness being between about 0.2 and 0.6.

19. The gas turbine engine according to claim 18 , wherein said at least one of said vane assemblies is in said compressor section.

20. The gas turbine engine according to claim 19 , wherein said at least one shroud is said radially outer shroud.

21. The vane and shroud according to claim 18 , wherein said lug merges into a transition section which curves circumferentially inwardly from said lug to said airfoil, and said radial wall is generally radially aligned with a radial extent of said transition section which is most adjacent to said radial wall.