Monolithic structure having improved flaw tolerance
US5980206A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | May 31, 1996 |
| Grant date | Nov 9, 1999 |
| Priority date | — |
| Expiry date | May 31, 2016 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB64C27/32
- WIPO fieldTransport
- WIPO sectorMechanical engineering
Abstract
A monolithic structural member (10) operative for reacting steady and vibratory bending moment loads M about an applied loads axis X and having a specially configured cross-sectional configuration for providing improved flaw tolerance. The cross-sectional configuration (10) includes a central connecting element (18) and at least one pair of structural ribs (14a, 14b) being integrally formed with the central connecting element (18) and projecting outwardly thereof. The structural ribs (14a, 14b) are, furthermore disposed in the tensile field produced by the steady portion of the bending moment loads M and are proximal to the centroid C.sub.T of the cross-section (10). The cross-sectional configuration (10) defined by the structural ribs and connecting element produces a partial inertia ratio I.sub.X /I.sub.Y greater than or equal to 1.0, which partial inertia ratio I.sub.X /I.sub.Y has the advantageous effect of retarding or arresting crack propagation in the structural member (10). The cross-sectional configuration (10), as adapted for use in a helicopter rotor hub assembly (50), provides improved flaw tolerance and improved clearance between rotor hub assembly components. Specific…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.