Strength of wires

Taitsman, 1. P. and Saha, S. 1977. Tensile strength of wire-reinforced bone cement and twisted stainless-steel wire. J. Bone Joint Surg. 59A 419. 

Beta C Typical ultimate shear and tensile strength of wire at RT... 

Beta C typical ultimate tensile and shear strength of wire and bar at RT (continued)... 

Potting. Potting of wire insulated with Tefzel has been accompHshed with the aid of a coating of a coUoidal siHca dispersion. The pots produced with a polysulfide potting compound meeting MIL-S-8516C Class 2 standards exhibit pullout strengths of 111—155 N (25—35 Ibf). 

Characteristics of the wire materials, which are cmcial to the strength of the wire bond, include wire dimensions, tensile strength, elongation, and... 

Wire and cable insulation based on vulcanizates of PZ has also been studied. Again, low fire risk was the target property, and this was achieved. The need to vulcanize the coating, somewhat modest tensile properties, tensile strength of 5.2 to 12.2 MPa (760 to 1770 psi), and high dielectric constant (4—5 at 10,000 Hz) limited interest in this appHcation (19). 

In the soldedess wrap (Fig. 3) or wire-wrap connection, a wire conductor is coiled around the back end of the separable contact, which has a square or rectangular cross section (4). The corners of the soldedess wrap post and the areas of the wire that are in contact with it are severely deformed. In a propedy made wrap, the force required to sHde the wire along the post exceeds the breaking strength of the wire. The method is suitable only for soHd wire, and special tools are used to make this connection. 

Estimate the tensile strength of the wire and the work required to take 1 m of the wire to the point of necking. 

There are less exotic ways of increasing the strength of cement and concrete. One is to impregnate it with a polymer, which fills the pores and increases the fracture toughness a little. Another is by fibre reinforcement (Chapter 25). Steel-reinforced concrete is a sort of fibre-reinforced composite the reinforcement carries tensile loads and, if prestressed, keeps the concrete in compression. Cement can be reinforced with fine steel wire, or with glass fibres. But these refinements, though simple, greatly increase the cost and mean that they are only viable in special applications. Plain Portland cement is probably the world s cheapest and most successful material. 

A mast raised and lowered by wire rope shall have the wire rope sized to have a nominal strength of at least 2- times the maximum load on the line during erection. 

Selection and testing of wire prior to rope fabrication will be adequate to ensure the after-fabrication wire rope breaking strength and wire requirements can be met. Prior to fabrication, wire tests should meet the requirements of Table 4-10. 

Note The diameter of wire can more easily and accurately be determined by placing the wire specimen in the test machine and applying a load not over 25% of the breaking strength of the wire. 

---