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
Waterproof wound protector
SMS transport resource control
Method and apparatus for allocating and obtaining IP address
Method of isolating human neuroepithelial precursor cells from human fetal tissue
Magnetic resonance imaging apparatus for use with radiotherapy
System and method for determining payroll related insurance premiums
  Randomly Featured Patents
Method for filling pressurized gas into a cylinder device
Pesticidal and parasiticidal use of 2-(substituted thio) thiazolo-[4,5-b]pyridine compounds
Cerebral palsy arm and hand brace
Digital memo recorder having removable memory unit for vehicle interior
Routing table management method using interface ID in the IPv6
Dross cooling system and cooling method
Optimized ridge apertures for thermally assisted magnetic recording
Apparatus for manufacturing a confection
Spherical optical splitter/combiner
Swingable support for concealably mounting antennas on vehicles