Stresswave, Inc.

Fatigue Technology, Inc.

Eric T Easterbrook

Leonard F Reid

Charles M Copple

Michael A Landy

Roger T Bolstad

Darryl E Quincey

Richard Z Jarzebowicz

Mark R Weiss

Louis A Champoux

Joy Sarah Ransom

Nils Juhlin

Michael Landy

Taeksun Nam

Todd L Thompson

Milton Sigelmann

Louis A Champoux, Deceased

Charles A Copple

William B Walsh

Repaired rotors are provided. The rotors are repaired by using an indenter apparatus for plastically straining original portions of the rotor and adjacent repair welds. The weld nugget, adjacent heat affected zones, and the adjacent parent-metal portions or new metal portions, are indented at a weld nugget and heat affected zone, to produce threshold levels of uniform plastic strain which meet or exceed plastic strain levels that provide, when the weld nugget and heat affected zone is heat treated, a recrystallized grain structure metallurgically comparable to the grain structure of the original parent-metal of the rotor. Repaired integrally bladed rotors for gas turbine engines, such as aircraft engines, are provided. Blades for gas turbine engines, including integrally bladed rotors, may be advantageously provided, having been manufactured or repaired as described.

Integrally repaired bladed rotor

A method for design in indenter apparatus for plastically straining a workpiece including a weld nugget, adjacent heat affected zones, and the adjacent parent-metal portions or new metal portions, throughout the weld nugget volume and heat affected zone, to produce threshold levels of uniform plastic strain which meet or exceed plastic strain levels that provide, when the weld nugget and heat affected zone is heat treated, a recrystallized grain structure metallurgically comparable to the grain structure of the parent-metal. The indenter provided by the optimization methods may be used to advantageously in a method for the repair of damaged rotors, including integrally bladed rotors, in gas turbine engines, such as in aircraft engines. Blades for gas turbine engines, including integrally bladed rotors, may be advantageously provided constructed by the methods taught.

Method for integral turbine blade repair

A method of installing fastening elements, and rivetless fasteners for use with the method. Rivetless nutplate fasteners are installed in metal structures by providing flush fit barrel shaped plug or bushing portions in a hole in the structure as defined by an edge wall. The barrel portion is acted upon axially, and expanded radially outward toward the edge wall of the hole, to provide an interference fit. The ends of the barrel portion are machined as desired for flushness. Also, a hole is installed as necessary. Rivetless nutplates are easily installed, and the installation enhances fatigue life of the hole surrounding the barrel of the nutplate.

Method for attaching a nut element to a metal structure

A method for cold working metal structures. A compound indenter is used to produce deformation in a workpiece, to provide a selected beneficial residual stress profile, to provide improved fatigue life structures with minimal manufacturing steps. A compound indenter deforms a workpiece, resulting in dimples therein. A relatively uniform beneficial residual stress profile is provided at the surface and at the midplane of apertures in a workpiece, so as to improve overall fatigue life. A compound indenter tool having a first, elongate indenter with a shaped indenter surface portion, and a second shaped indenter surrounding the first indenter and forming an annular shoulder recessed from the surface portion of the first indenter, is used. Optionally, a foot having a bottom portion is used to confiningly surround an indenter during application of deforming force to the surface of a workpiece, to prevent deformation of adjacent workpiece surface.

Method for manufacturing improved fatigue life structures, and structures made via the method

Metal cold-working tooling and a method of employing such tooling. The tooling is used to produce deformation in a workpiece, to provide a selected beneficial residual stress profile in the workpiece, in order to provide high fatigue life structures in a minimum number of manufacturing steps. An indenter is used to coldwork a workpiece, causing dimples in the workpiece. Preferably, the dimples are provided with a shape formed by application of a uniform pressure profile to the workpiece surface. As optimized, a relatively uniform beneficial residual stress profile is provided at both the surface and at the midplane apertures in a workpiece, so as to improve overall fatigue life. Also, an improved indenter tool profile shape is described, having a smoothly curved indenter surface portion. And, the use of consumable lamina wafers provides the benefit of easy application of uniform stress profile to a workpiece.

Method and apparatus for improving the fatigue life of components and structures

A method of manufacturing a fatigue life enhanced product from a plurality of workpiece parts. At least one fatigue enhancing operation is performed on a first workpiece at a first work station. At least one fatigue enhancing operation is performed on a second workpiece at a second work station. The first and second workpieces are transferred to a first assembly station, where the workpieces are joined to form a fatigue life enhanced product. Aerostructures manufactured according to the method may include components fabricated at different locations to have fatigue life enhancing properties, especially in bounding material adjacent to holes designed to accommodate fasteners. By use of the method, the final assembly step can thus avoid the necessity to include the processing of holes to enhance fatigue life, since this step has been performed prior to bringing components into position to be joined in the final shape or assembly of the airframe.

Method of building fatigue life enhanced structures

A compound indenter for metal coldwork, and a method of employing such tooling. The compound indenter tool is used to produce deformation in a workpiece structure, to provide a selected beneficial residual stress profile in the workpiece, in order to provide high fatigue life structures in a minimum number of manufacturing steps. Preferably, action of a compound indenter causes deformation of the workpiece, causing dimples in the workpiece. By optimized use of the method, a relatively uniform beneficial residual stress profile is provided at both the surface and at the midplane apertures in a workpiece, so as to improve overall fatigue life. An improved, compound indenter tool profile shape is described, having a first, elongate indenter with a shaped indenter surface portion, and a second shaped indenter surrounding the first indenter and forming an annular shoulder recessed from the surface portion of the first indenter. Additionally, a foot having a bottom portion can be used to confiningly surround the second indenter during application of force to the surface of a workpiece, to prevent surface deformation.

Method and apparatus for manufacturing structures with improved fatigue life

Metal coldworking tooling and a method of employing such tooling. The tooling is used to produce deformation in a workpiece, preferably via use of stress waves, to provide a selected beneficial residual stress profile in the workpiece, in order to provide high fatigue life structures in a minimum number of manufacturing steps. Preferably, action of an indenter causes propagation of stress waves to coldwork a workpiece, causing dimples in the workpiece. Preferably, the dimples are provided with a shape formed by application of a uniform pressure profile to the workpiece surface. By optimized use of the method, a relatively uniform beneficial residual stress profile is provided at both the surface and at the midplane apertures in a workpiece, so as to improve overall fatigue life. An improved indenter tool profile shape is described, having a smoothly curved indenter surface portion. Also, the use of a consumable lamina wafer technique provides the benefit of easy application of uniform stress profile to a workpiece.

Method and apparatus for producing beneficial stresses around apertures, and improved fatigue life products made by the method

Metal coldworking tooling and a method of employing such tooling. The tooling is used to produce deformation in a workpiece, preferably via use of stress waves, to provide a selected beneficial residual stress profile in the workpiece, in order to provide high fatigue life structures in a minimum number of manufacturing steps. Preferably, action of an indenter causes propagation of stress waves to coldwork a workpiece, causing dimples in the workpiece. Preferably, the dimples are provided with a shape formed by application of a pre-selected pressure profile to the workpiece surface. By optimized use of the method, a relatively uniform beneficial residual stress profile is provided at both the surface and at the midplane apertures in a workpiece, so as to improve overall fatigue life.

Method and apparatus for improving the fatigue life of components and structures using the stresswave process

Tooling and a method of employing tooling to produce beneficial stress waves in a substrate to provide high fatigue life structures. Stress waves are provided to work a substrate, causing dimples in the workpiece, along a uniform pressure profile in the workpiece. By use of the method, uniform beneficial residual stress is provided at surface and midplane apertures in a workpiece, so as to improve overall fatigue life. An improved tool shape is described, having a smooth curve, rather than a flat punch. Also, the use of a consumable wafer provides additional uniform stress profile benefits.

Method and apparatus for producing beneficial stresses around apertures by use of focused stress waves

Method and apparatus for producing beneficial stresses around apertures by use of focused stress waves, and improved fatigue life products made by the method

A nosepiece apparatus for use in conjunction with a pull gun for prestressing fastener holes, or the like, in a workpiece, the nosepiece including an adapter (12) having a central passageway (19) therethrough and a rear end (20) adapted to be mounted to a pull gun. The forward end of the adapter (12) has a threaded connection for coupling the adapter (12) to an extension piece (14). The extension piece (14) is an elongated, tubular extension having threaded connections at both ends. A sleeve retainer (16) is provided having a threaded connection at its rearward end for securing the sleeve retainer (16) to the extension. The forward end of the sleeve retainer (16) is formed by a multiple of annularly-spaced, alternate splits (56) and fingers (58) extending substantially axially from the rearward end of the sleeve retainer (16). The threaded connection of the sleeve retainer (16) is adapted not only to be threadably coupled to the extension piece (14), but also to be directly coupled to the adapter ( 12).

Apparatus for split sleeve and tubular bushing cold expansion

A circular opening (54) is formed in a wall (12). A tubular shank (42) of a nut mounting unit (40) is inserted into the opening (54). The unit (40) is moved endwise to place a nut cage base (46) against the wall (12). A split sleeve (82) is installed on a small diameter portion (90) of a mandrel (M). The mandrel (M) and sleeve (82) are inserted into the tubular shank (42) from the side of the wall (12) opposite the nut cage (44). The mandrel (M) is then retracted to successfully move increasing and maximum diameter portions (90, 92) of the mandrel (M) through the split sleeve (82). The mandrel portions (92, 94) exert a radially outwardly expanding force on the split sleeve (82). The split sleeve (82) in turn imposes a radially outwardly expanding force on the tubular shank (42). This causes a plastic deformation of the tubular shank (42), creating a tight interference fit between the tubular shake (42) and the sidewall of the opening (54). In this manner, the unit (40) is firmly secured to the wall (12). Next, a nut (20) is inserted into the nut cage (44), between end stops (56, 58). A retainer spring (68) is placed over the base (24) of the nut (20), and is compressed an amount sufficient to move side portions (64, 66) together enough that they will fit between cage sidewalls (48, 50). Then, the squeezing force on the retainer spring (68) is released, allowing side portions (64, 66) to move outwardly into openings (60, 62) in the sidewalls (48, 50). In this position the sidewalls (48, 50) restrain sideways movement of the nut. The end stops (56, 58) restrain endwise movement of the nut (20). The inner spring (68) prevents movement of the nut (20) out from the nut cage (44).

Nut cage and mount

An internally lubricated, longitudinally split sleeve is positioned on a small diameter portion a mandrel having a rear end connected to a piston with a puller tool. The rear end of the split sleeve is flared and is against the front end of a tubular sleeve stop which immediately surrounds the mandrel. The puller tool includes a tubular sleeve holder which surrounds the sleeve stop. A forward main portion of the sleeve holder is separated by a pair of longitudinal slots into a pair of elongated fingers. The forward ends of the fingers define a sleeve and mandrel receiving end opening and jaws radially outwardly bounding the opening. The mandrel and sleeve holder are both extended and then the puller tool is moved into alignment with a sleeve and is moved endwise to push the mandrel through the sleeve until the flared end of the sleeve is against the sleeve stop. Then the sleeve holder is retracted. Next, the mandrel and sleeve are inserted into a hole in a workpiece and the tool is moved forwardly until the front ends of the jaws are against the workpiece. Then, the puller tool is operated to retract the mandrel through the sleeve and into the sleeve stop. Retraction of the mandrel moves first an increasing diameter portion of the mandrel and then a maximum diameter portion of the mandrel through the sleeve which radially expands the sleeve and cold expands the material immediately surrounding the hole in the workpiece. After the mandrel is retracted into the sleeve stop, the puller tool is moved away from the workpiece. The jaws of the sleeve holder engage and retain the sleeve so that the sleeve is pulled out from the hole in the workpiece.

Split sleeve cold expansion

A circular opening (48) is formed in a structural wall (12). A tubular shank (28) of a nut mounting grommet (26) is inserted into the opening (48). The grommet (26) is moved endwise to place a shoulder surface (34) on the base of a nut mounting cup (30) against the wall (12). A split sleeve (54) is installed on a small diameter portion (62) of a mandrel (52) and the mandrel and sleeve (52, 54) are inserted into the tubular shank (28) from the side of the wall (12) opposite the nut receiving cup (30). The mandrel (52) is then retracted to successively move increasing and maximum diameter portions (64, 66) of the mandrel (52) through the split sleeve (54). The mandrel portions (64, 66) exert a radially outwardly expanding force on the split sleeve (54). The split sleeve (54) in turn imposes a radially outwardly expanding force on the tubular shank ( 28). This causes a plastic deformation of the tubular shank (28), creating a tight interference fit between the tubular shank (28) and the sidewall of the opening (48). In this manner, the grommet (26) is firmly secured to the wall (12). Next, a nut (24) is inserted into the cup (30) with its threaded central opening (18) in alignment with the passageway through the tubular shank (28). The sidewall of the cup (30) is deformed, to place portions of a lip (46) endwise of the nut (20), in the path of removal of the nut (20) from the cup (30). The sidewall of the cup (30) includes wrench flats (98) outwardly bounding wrench flats (100) on the nut (20).

Growing community of inventors

Kent, WA, United States of America

Eric T Easterbrook