Resources Contact Us Home
Nondestructive fatigue test method for ferromagnetic construction materials

Image Number 3 for United States Patent #6345534.

A nondestructive test method determines fatigue of a test ferromagnetic construction material by quantifying a change in effective stress due to aging of the test material, in which the magnetic susceptibility (.chi..sub.c) of the test material is measured in its aged state under a magnetic field having a specified intensity (H) according to a relation as expressed by a first equation: c=.chi..sub.c H.sup.3. The magnetic susceptibility (.chi..sub.c) so measured and the magnetic field intensity (H) are put into the first equation, to obtain a susceptibility coefficient (c) of the test material. The susceptibility coefficient (c) so obtained is put into a second equation: .sigma.={log (c)-a}/b, where a and b are known constants determined by an internal structure of the test material, to obtain a current tensile stress (.sigma.) of the test material. The current tensile stress (.sigma.) of the test material so obtained is compared with a known, initial tensile stress (.sigma..sub.0) of the same test material, to determine a change in effective tensile stress of the test material.

  Recently Added Patents
Secure soft SIM credential transfer
Fast carrier allocation in multi-carrier systems
Anthranilic diamide compositions for propagle coating
Hand-held electronic display device
Media processing method and device
Motor drive component verification system and method
  Randomly Featured Patents
Polymorphs of dasatinib isopropyl alcohol and process for preparation thereof
Swivelable quick connector assembly
Mechanical device for combining first and second control orders, and an aircraft provided with such a device
Pyridine derivatives
Information service method and information service system
Refrigeration cycle
Demodulator for high bit rate transmission and corresponding demodulation method
Touch input program and touch input device
Methods and compositions for treating post-myocardial infarction damage
Viscosified treatment fluids comprising scleroglucan or diutan and associated methods