Advanced Materials for Temperatures above 1500°C - Development of Testing Methods

      Projekt: Foschungsprojekt



      The aim of the project is to carry on the development of already imple-men-ted non-contacing strain and displacement measurement equip-ment based on laser techniques. The following three laser methods will be compared:
      - Interferometric strain/displacement measuring system using 2 micro-hardness indentations about 100 µm apart as markers. Displacement re-solution approx. 2 nm, strain resolution between 10-5 and 10-3 (one dimensional).
      - Speckle pattern interferometer, displacement resolution ~40 nm, strain resolution 10-4 , two-dimensional, evaluated area in the range of square centimeters.
      - Electronic speckle pattern correlation method, displacement resolution ~2 µm, strain resolution 10-5, two spots of several mm² up to 20 mm apart.
      Laser based methods for non contacting strain and displacement measure-ments are well known. However, the application of the methods to strain measurements at standard testing machines suffers from several problems like vibration of the machine, out of plane movement and torsion of the specimen during application of the force. Not much
      attention has been paid up to now by other workers to such problems, which arise even at room temperatures.
      Plan of research
      Comparative evaluation of the three laser based systems by strain meas-ure-ments at room temperatures.
      - Comparison of non-contacting extensometric methods with conventio-nal strain measuring systems.
      - Application of fiber optics t...(this text has been cut automatically)
      Tatsächlicher Beginn/ -es Ende1/01/9531/01/00