Crack Propagation Test-裂纹扩展-裂纹长度测量-E467-FRACTOTRON.pdfVIP

Practice Hint Crack Propagation Test Measurement of Crack Lengths by Compliance following ASTM E 674 Introduction The above mentioned method is practicable with good results on a resonant testing machine from RUMUL in connection with a strain transducer and the software „Crack Propagation“. The user has to run a pilot test to find out small adjustments which are allowed according to the standard. Behind this hint is the contact to Dr. Peter Hübner, Bergakademie Freiberg. He gave support to the method for finding the coefficients of the polynomial which calculates the crack length. CT-Specimen with single cardanic clevis and a COD-transducer FRACTOTRON This description gives details to a computer-controlled crack propagation test on a RUMUL 20kN resonant testing machine MIKROTRON in connection with a strain (COD -) transducer FRACTOTRON. The tests were done on Aluminium CT-specimens (W=50, B=19) at a test frequency of 75 Hz. This paper doesn’t make the online help system of the software useless; it contains much helpful information related to the program handling. What does the ASTM E 647 say? This standard describes a method to measure crack propagation rates at cyclic loading. Such a test is normally controlled by the cyclic stress intensity ∆K. For the load calculation from ∆K a continuous measuring of the crack length is essential. RUSSENBERGER PRÜFMASCHINEN AG Gewerbestrasse 10/Rundbuck CH-8212 Neuhausen am Rheinfall/Switzerland Phone +41 52 672 43 22 Fax +41 52 672 44 48 e-mail rumul@rumul.ch www.rumul.ch Practice Hint