Browse Prior Art Database

Measuring Torsional Properties of Tubes

IP.com Disclosure Number: IPCOM000090911D
Original Publication Date: 1969-Aug-01
Included in the Prior Art Database: 2005-Mar-05
Document File: 3 page(s) / 61K

Publishing Venue

IBM

Related People

Barrager, SM: AUTHOR [+2]

Abstract

The apparatus measures the torsional properties of a thin-walled tube which can be subjected to high torsional forces. The measurements provide for the determination of the damping constant, torsional rigidity, amplitudes of the torsional forces, and the frequency of torsional vibrations resulting from applied torsional forces.

This text was extracted from a PDF file.
At least one non-text object (such as an image or picture) has been suppressed.
This is the abbreviated version, containing approximately 53% of the total text.

Page 1 of 3

Measuring Torsional Properties of Tubes

The apparatus measures the torsional properties of a thin-walled tube which can be subjected to high torsional forces. The measurements provide for the determination of the damping constant, torsional rigidity, amplitudes of the torsional forces, and the frequency of torsional vibrations resulting from applied torsional forces.

A test fixture, capable of providing measurements for determining the criteria, is shown in drawing 1 in a loaded torsional force applying position. Drawing 2 shows the fixture and the tube to be tested during torsional vibrations. The fixture includes frame 10 having depending mandrel 11 for receiving thin-walled tube 12 to be tested. Clamp 13 secures the upper end of tube 12 to depending mandrel 11. Block 14 vertically slidably supports reciprocating table 15. Solenoid 16 moves table 15 between an upper locking position of drawing 1 and a lower unlocking position of drawing 2. Upstanding cylinder 20 is secured to the upper surface of table 15 and has a pair of upstanding locking pins 21. Inverted cup mandrel 22 is secured to the lower end of tube 12 such that it rotates with it.

In drawing 1, pins 21 releasably lock mandrel 22 to cylinder 20.

This includes a pair of kerfs 24 formed on chords for receiving a tool, not shown, for rotating cylinder 20 a few degrees to exert a torsional force on tube 12. Upon completion of a desired rotation,
i.e., the application of a predetermined torsional force, set screw 23 is tightened to hold cylinder 20, mandrel 22, and tube 12 against rotation to preserve the force applied. For making torsional measurements in different ranges of frequencies, inertial ring 25 is disposed about tube 12 adjacent mandrel 22. The mass of ring 25 can be...