Metal treatment – Process of modifying or maintaining internal physical... – Heating or cooling of solid metal
Reexamination Certificate
1998-10-27
2001-09-11
Wyszomierski, George (Department: 1742)
Metal treatment
Process of modifying or maintaining internal physical...
Heating or cooling of solid metal
C148S676000, C148S902000
Reexamination Certificate
active
06287399
ABSTRACT:
TECHNICAL FIELD
The present invention relates to a metallic article including a curved section which is resistant to buckling, and a method for manufacturing such a metallic article.
BACKGROUND OF THE INVENTION
When a compressive force is applied to a metallic member having a curved section in a chord-wise direction, it tends to buckle substantially more readily than a similar member which is straight in the axial direction, and has no such curved section. To prevent the buckling and eventual destruction of such a member, it has been customary to increase the cross sectional area of the curved section and to add a reinforcement such as a rib to the curved section.
However, such measures inevitably lead to the increase in the weight of the member, and the space required for accommodating such a member. In certain applications, such increase in the weight and need for additional space may not be acceptable. For instance, a reinforcement rib may interfere with other components.
In situations where a destructive axial force rarely occurs, and slight deformation of the member can be tolerated, it may be possible to avoid the destruction of the member by reducing the curvature of the curved section or by otherwise controlling the bucking of the curved section, instead of simple reinforcement.
BRIEF SUMMARY OF THE INVENTION
In view of such problems of the prior art, and the recognition by the inventor, a primary object of the present invention is to provide a metallic article having a curved section which can be made resistant to buckling without increasing the cross sectional area of the member or otherwise reinforcing the member.
A second object of the present invention is to provide a metallic article which is slender in shape and provided with a curved section, but resistant to buckling when subjected to an axial compressive force.
A third object of the present invention is to provide a method for manufacturing such a metallic article.
According to the present invention, these and other objects can be accomplished by providing a method for manufacturing a metallic article resistant to buckling, comprising the steps of: preparing a metallic article including a twin deformation system; compressing the metallic article until the twin deformation system is deformed beyond a region of twin boundary deformation; and restoring a part of the twin deformation system which has been deformed beyond a region of twin boundary deformation back to the region of twin boundary deformation so as to produce a first part which is restored to the region of twin boundary deformation, and a second part which is left deformed beyond the region of twin boundary deformation.
When a compressive load is applied to the thus prepared article, and the first part and the second part are both compressed, the first part can deform more readily than the second part so that the overall shape of the article changes as its deformation progresses. Therefore, by appropriately selecting the distributions of the first part and the second part, it is possible to change the shape of the article more suitable for withstanding the load. Typically, the distributions of the first part and the second part are selected such that the bending moment of the vulnerable part is reduced. For instance, the article may be provided with a curved section which deforms into a straight shape when subjected to a chord-wise compression. Typically, the article consists of an elongated member having a curved section therein which has the first part formed on an outside part of the curved section, and the second part formed on an inside part of the curved section. Thus, the article may be made resistant to buckling in spite of the presence of the curved section.
Typically, the twin deformation system is formed in a martensite phase. Such a state can be readily achieved in a Ni—Ti shape memory alloy.
The step of partly restoring the region of twin boundary deformation may comprise a step of bending the metallic article or, alternatively, a step of heating a part of the metallic article. According to yet another embodiment of the present invention, the first part and the second part originally consist of separate members which are processed individually so as to return to the region of twin boundary deformation and stay beyond the region of twin boundary deformation, respectively, and are subsequently joined together.
REFERENCES:
patent: 4450616 (1984-05-01), Morita
patent: 5611874 (1997-03-01), Zadno-Azizi et al.
patent: 5958154 (1999-09-01), O'Handley et al.
Honda Giken Kogyo Kabushiki Kaisha
Wyszomierski George
LandOfFree
Metallic article resistant to buckling does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Metallic article resistant to buckling, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Metallic article resistant to buckling will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2453432