Title of Invention

A MULTI AXIAL FATIGUE TESTING MACHINE

Abstract A fatigue testing machine comprising a motor for rotating a shaft on which are mounted an inertia loading mambe;a pair of supporting heads for mounting the test specimen;a lever and dead weight arrangementt for loading the test specimen,cheracterised in that one end of the test specimen is attached to a rotatable disc having spaced slots cut on the face disc;an electromagnet interposed at the outer periphery of the disc whereby when a.b.c.voltage is applied to the coil of the magnet,the resulting cyclic magnetic force acting on the said magnet,the resulting cyclic magnetic force acting on the said disc produces a counter torque on the said shaft and thus a counter torque on the test specimen, thereby inducing a cyclic torsional stress on the test specimen
Full Text

This invention relates to a fatigue testing machine.
The known fatigue testing machine is a machine for assessing the effect of stresses on a test specimen, such as, bending or torsion stresses on the application of a load. Torsion combined with either tension or bending of a solid shaft has been used extensively because it duplicates one of the more important multi-axial loading conditions found in structures and components.
This invention proposes a multi-axial fatigue testing machine incorporating a torsional exciter operating electro-magnetically.
The fatigue testing machine, according to this invention, comprises a motor for rotating a shaft on which are mounted an inertia loading member; a pair of supporting heads for mounting the test specimen; a lever and dead weight arrangement for loading the test specimen, characterised in that one end of the test specimen is attached to a rotatable disc having spaced slots cut on the face of the disc ; an electromagnet interposed at the outer periphery of the disc whereby when a d.c. voltage is applied to the coil of the said magnet, the resulting cyclic magnetic force acting on the said disc produces a counter torque on the said shaft and thus a counter torque on the test specimen, thereby mducing a cyclic torsional stress on the test specimen.
The disc is made of a lightweight non-magnetic material, such as, aluminium.

The accompanying drawings illustrate, by way of example, and not by way of limitation, one of various possible embodiments of the fatigue testing machine proposed herein.
A motor 1 rotates a shaft on which are mounted an inertia loading member 2 a pair of supporting heads 4 for mounting the test specimen. A universal coupling is indicated by 3.
A lever and dead weight arrangement 6 is provided for loading the test specimen 8. The load point is indicated by 7.
The above mentioned machine is characterised in that one end of the test specimen 8 is attached to a rotatable aluminium disc 9, said disc having spaced slots 11 cut on the face of the disc.
An electromagnet is interposed at the outer periphery of the disc 9 whereby when a d.c. voltage is applied to the coil 10 of the said magnet, the resulting cyclic magnetic force acting on the said disc 9 produces a counter torque on the said shaft and thus a counter torque on the test specimen 8 thereby inducing a cyclic torsional stress on the test specimen 8.
The disc is made of a lightweight non-magnetic material, such as, aluminium.
The machine proposed herein is versatile and suitable for laboratory use as well as advanced R&D work.






We Claim:
LA fatigue testing machine comprising a motor for rotating a shaft on which are mounted an inertia loading member; apair of supporting heads for mounting the test specimen; a lever and dead weight arrangement for loading the test specimen, characterised in that one end of the test specimen is attached to a rotatable disc having spaced slots cut on the face of the disc ;an electromagnet interposed at the outer periphery of the disc whereby when a d.c. voltage is applied to the coil of the said magnet, the resulting cyclic magnetic force acting on the said disc produces a counter torque on the said shaft and thus a counter torque on the test specimen, thereby inducing a cyclic torsional stress on the test specimen. 2.A fatigue testing machine as claimed in Claim 1 wherein the disc is made of aluminium.
3.A fatigue testing machine substantially as herein described with reference to, and as illustrated in, the accompanying drawings.


Documents:

705-che-2004-claims.pdf

705-che-2004-correspondnece-others.pdf

705-che-2004-correspondnece-po.pdf

705-che-2004-description(complete).pdf

705-che-2004-drawings.pdf

705-che-2004-form 1.pdf

705-che-2004-form 19.pdf

705-che-2004-form 26.pdf


Patent Number 206754
Indian Patent Application Number 705/CHE/2004
PG Journal Number 26/2007
Publication Date 29-Jun-2007
Grant Date 11-May-2007
Date of Filing 20-Jul-2004
Name of Patentee M/S. INDIAN INSTITUTE OF TECHNOLOGY
Applicant Address IIT P.O. CHENNAI 600 036.
Inventors:
# Inventor's Name Inventor's Address
1 MR.DR.MINNAL MUTHUVEL MAYURAM IIT P.O. CHENNAI 600 036.
PCT International Classification Number G01N-3/32
PCT International Application Number N/A
PCT International Filing date
PCT Conventions:
# PCT Application Number Date of Convention Priority Country
1 NA