Removable strain gauge fixture and method for measuring accumulated strain in a material

US4526039A · kind A · utility

Assignee

• The United States of America as represented by the Secretary of Transportation · US

Inventors

• Harry L. Ceccon · Boston, US
• Richard Murphy · Oak Park, US
• H. David Reed · Carlisle, US
• Oscar Orringer · Duxbury, US

Key dates

• Filing date: Jun 23, 1983
• Grant date: Jul 2, 1985
• Expiry date: Jun 23, 2003

Classification

• Technology area (CPC G): Physics
• CPC primary: G01B7/16
• WIPO field: Measurement
• WIPO sector: Instruments

Abstract

The invention encompasses a removable strain gauge fixture, and a method for measuring accumulated stress in a structural component, such as a railroad rail. The strain gauge fixture generally comprises first and second side pieces connected by a strain concentrating bar of reduced cross-section, an electronic strain sensor mounted on the bar, and first and second tapered pins extending from the front faces of each of the side pieces. The tapered pins transmit accumulated strain from the component being measured to the strain focusing bar when the pins are inserted into mating holes in the component. The method of the invention generally comprises the steps of providing a pair of holes in the component mateable with the tapered pins of the strain gauge fixture, inserting the tapered pins into the holes of the material in order to transfer accumulated strain in the material to the strain concentrating bar, taking a first strain measurement via the strain sensor on the bar, removing the tapered pins from the material, and taking a second strain reading from the strain sensor.