A technical press release usually announces the development of anew product. The audience for such adocument consists of writers and editors of trade journals, wherethe product may be reviewed and potential customers who mightwant purchase the new product.
A technical press release contains the following elements:
An example of a press release follows.
The ShearTubeTM ShearDamperTM forPrecisionMachine Tools
Winner of a 1994 R&D 100 Award as being one of the 100 mosttechnologically significantnew products of the year.
A ShearTubeTM ShearDamperTM allows anengineer to highly damp a structure without imposing strictlimits on the structure's geometry or materials. As shown above,the ShearTubeTM damper is incorporated into astructure in the following manner:
- The structure has rough holes formed in it (casting, drilling, or welding in a pipe).
- The holes may be any shape, but should maximize the cross-section perimeter (e.g., a square).
- The neutral axes of the holes must be as far away as possible from the neutral axis of the structure.
- Ideally, the holes almost fill the structure (e.g., four squares inside of a large square beam).
Modestly smooth-surfaced tubes (0.5 mm Ra) that are 3-5 mm smaller than the hole are covered with a high loss damping material (e.g., ScotchdampTM). The tubes are suspended into the hole, and an epoxy replicant (e.g., VibradampTM from Philadelphia Resins) is injected (poured) around the tubes. After the epoxy hardens, the component is ready to be used. To achieve excellent temperature control of the machine, the ShearTubesTM are used like heat exchanger tubes to channel temperature-controlled fluid inside the machine.
Good stiffness and damping are necessary, but not individuallysufficient, requirements of a precision machine. Typically,damping in a machine is obtained from the materials and microslipin the joints. The net result is that cast-iron structures haveamplification-at-resonance factors on the order of 200. Polymerconcrete structures can have 5-10 times more damping than cast-iron structures.
However, many advanced materials (e.g., ceramics) have very poordamping and require an additional damping mechanism. TheShearTubeTM ShearDamperTM is a viscousshear damper that can be readily incorporated into machinestructures. Applications include all types of machines wherevibration needs to be damped.
This design is fundamentally different from earlier constrainedlayer damper designs (e.g., exterior plates which had a tendencyto delaminate or require tight manufacturing tolerances) in thatthe dampers are in the internal shear of a thin film ofviscoelastic material. Since the neutral axes of the tubes aredisplaced from the neutral axis of the structure, bending of thestructure causes relative motion to occur between the twosurfaces. This motion shears the viscous fluid and dissipatesvibration energy at a rate orders of magnitude higher than wouldnormally occur in the material of the structure or in its joints.
In addition, the tubes make excellent heat exchanger tubes inwhich temperature controlled fluid can be circulated. Thisallows machines to achieve virtually isothermal performance whichgreatly minimizes errors, as opposed to other vibrationmitigation systems based on solid poured materials.
This concept allows machine tool builders to design a machinewith integrally cast longitudinal holes which can haveShearTubeTM dampers installed if the customerrequests a high damping option on the machine order form. Thusthe concept facilitates modular construction of machine tools.
For questions of a technical nature, contact Prof. AlexanderSlocum, and for questions of a commercial nature, contact Mr.Richard Slocum. Please send your inquiries in writing to:
Dr. Alexander Slocum
PO Box 2126
Concord, NH 03302-2126
Fax: (603) 224-5369
Mr. Richard Slocum
200 Forest Trail
Nicholasville, KY 40356-9150
Fax: (606) 224-8080
The McGraw-Hill Companies, Inc..