Semicontinuous Mathematical Model for Bending of Multilayered Wire Strands

Semicontinuous wire strand modeling is an approach by which each layer of a strand is mathematically represented by an orthotropic cylinder whose mechanical properties are chosen to match the behavior of its corresponding layer of wires. Such a semicontinuous model is herein proposed for the analysis of multilayered wire strands under bending, tensile, and torsion loads. It is based on continuum mechanics and elasticity of orthotropic materials. The model permits the evaluation of strand stiffness, contact stress, interlayer shear stress, and interlayer slip. Results are obtained and given for a seven-wire strand and for selected steel reinforced aluminum conductors (ACSRs). Comparisons are made with results from two existing models that use a more classical approach, from another model that uses a semicontinuous approach, and from published experimental works. Under tensile and torsion loads, it is shown that the present semicontinuous model gives very accurate results. Under bending load, validation is more difficult to establish, but this new model is very promising.