Static Response of a Strand

Abstract

Figure 3.1 shows the configuration and cross section of a loaded simple straight strand. The strand consists initially of a straight center wire of radius, R₁, surrounded by m₂ helical wires (six wires are actually shown) of wire radius, R₂. It will be assumed, for the present, that the center wire is of sufficient size to prevent the outer wires from touching each other. This is generally the case, since it tends to minimize the effect of friction in the bending of a strand. Hence, the initial radius of the helix of an outside wire is given by the expression

$$ {r_2}\,\, = \,\,{R_1}\,\, + \,\,{R_2}. $$

(3.1)

An expression will now be derived to determine the minimum value of R₁ so that the outside wires will not be touching each other.