Light conduit arrangement for monitoring a physical condition of a structural part

• US 4,840,480 A
• Filed: 08/04/1982
• Issued: 06/20/1989
• Est. Priority Date: 08/12/1981
• Status: Expired due to Fees

• Current Assignee: Koninklijke Philips N.V.
• Original Assignee: Philips Kommunikations Industrie A
• Inventors: Federmann, Helmut, Starke, J. Peter, Levacher, Friedrich K.
• Primary Examiner(s): McGraw, Vincent P.
• Assistant Examiner(s): TURNER, SAMUEL A
• Application Number:
  US06/405,095
• Time in Patent Office: 2,512 Days
• Field of Search: 356/32, 356/34, 250/227, 73/800, 73/786, 340/550, 340/555, 340/564
• US Class Current: 356/32
• CPC Class Codes: G01M 11/086 Details about the embedment of the optical fiber within the DUT

Abstract

A structural element is provided with at least one light conduit which is arranged thereon under a selected mechanical initial stress. In this manner, the deformation or breakage can be detected at loads or deformations which are lower than the breaking loads or deformations of the component parts to be monitored.

Claims

1. A light conduit arrangement for monitoring physical conditions, such as breakage or deformation, of a structural part, comprising at least one light conduit whose breaking elongation is greater than that of the structural part, the light conduit having its terminal portions connectable respectively to a light source and a light receiver, an intermediate portion of the light conduit being secured to the structural part under an initial mechanical stress relative to the structural part, and the initial mechanical stress being selected such that the resulting breaking elongation of the prestressed intermediate portion is less than that of the structural part.

2. A light conduit arrangement as defined in claim 1, comprising a plurality of light conduits secured to the structural part to be monitored at different mechanical initial stresses.

3. A light conduit arrangement as defined in claim 1, comprising a plurality of light conduits arranged at a definite mechanical prestress on or in the structural part, said light conduits intersecting each other to form a coordinate-like pattern.

4. A light conduit arrangement as defined in claim 1, wherein said structural part has a tubular configuration and at least one light conduit is coiled under a definite mechanical prestress on said structural part.