Method of pre-stressing a structural member
US4501058A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Sep 24, 1981 |
| Grant date | Feb 26, 1985 |
| Priority date | — |
| Expiry date | Sep 24, 2001 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T403/48
- WIPO fieldMechanical elements
- WIPO sectorMechanical engineering
Abstract
The following specification discloses the use of a nickel titanium alloy component referred to as Nitinol for purposes of providing a pre-stressed structure. The alloy component provides stiffness to shell structures and tubular members such as oil well pipes, and conduits, as well as pre-stressed loadings for head bolts on engines or other pre-stressed fasteners. Pre-stressing is accomplished by deforming the Nitinol component below its transformation temperature which can be a cryogenic temperature, after which the Nitinol component returns by its memory to a desired shape for pre-stressing. The foregoing develops a large pre-load on a structural joint, so that successful design applications of Nitinol can pre-load joints with minimum load path offset for a shell or other structure. This minimizes in-plane local moments, as well as eccentric loading, and provides joints of lower weight and less internal volume protrusion.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.