Apparatus for reducing thermal stress in turbine airfoils

This invention relates generally to airfoils and, more particularly, to turbine airfoils with parted spars. A turbine airfoil includes at least one spar arrangement having a length less than an associated turbine airfoil length. During operation, the turbine airfoil has an outer skin surface which operates at a substantially higher temperature than that of an internal supporting parted spar arrangement. The parted spar arrangement permits the turbine airfoil outer skin surface to thermally expand between spar arrangements, thus preventing self-constraining thermal stresses from forming within the spar arrangement or the airfoil skin surfaces.