I have been asked to give more details on Dr Cloutier's contribution to the field of overhead electrical conductors (power transmission lines) mechanics. I just received the attached document, written by one close colleague of his, Dr. Claude Hardy, who retired from IREQ, Hydro-Quebec research branch. A nice tribute to Louis Cloutier's legacy.
My friend and former colleague, Dr. Louis Cloutier, passed away on February 26. A long time Hydro-Quebec engineer, among other achievements, he will be remembered for his major contribution to the solution of electric power transmission mechanical problems, most notably to Aeolian vibration control, and related conductor fatigue.
The classical problem of a cable under axial load has been revisited by Weiguo Wu and Xin Cao: Mechanics model and its equation of wire rope based on elastic thin rod theory, International Journal of Solids and Structures, in press, 9 pages. On line 22 october 2016 at http://www.sciencedirect.com/science/article/pii/S0020768316303122 .
Model is applied to a multistrand ccable given in a book by Costello (1990). Axial stiffness results compare very well.
As indicated in the review by Cardou & Jolicoeur (1997), and depending on the application, a helically stranded system may be modelled using a semi-continuous approach whereby each layer is replaced by a continuous helical orthotropic material. For those able to read Russian, this approach is presented in a paper by Danilin & Al. specifically oriented towards Overhead Electrical Conductor mechanics: “Modelling of Deformation of Wire Spiral Structures” published in the PNRPU Mechanics Bulletin (2015, No 4, pp. 72-93).
A paper by Kubelwa et al. (Statistical Modelling of Bending Stress in ACSR Overhead Transmission Line Conductors subjected to Aeolian Vibrations –I) reports data from vibration tests on 4 ACSR. under 3 axial loads (20, 25 and 30% UTS). An 84.5 m conductor span is vibrated at various bending amplitudes and strain is measured near a clamped end (distance not given). Clamps are rigid square-faced bushings. Vibration amplitude is measured at 89 mm from bushing. Strain gages are glued on 3 adjacent top layer wires. Through Hooke’s law, mean stress is derived for each amplitude.
In a paper to appear and available online,( An analytical approach to model the hysteretic bending behavior of spiral strands, Applied Mathematical Modeling 2016, http://www.sciencedirect.com/science/article/pii/S0307904X16300592 )
A new paper by Chen et al.: Experimental research on bending performance of structural cable. In: Construction and Building Materials, 15 October 2015, Vol. 96, pp. 279-288. Equivalent bending stiffness has been obtained applying a force at midspan of simply supported, about one meter long, specimens. A number of tensile force levels have been applied (including zero). Non-linear force-deflection curves are shown.
The International Electrotechnical Commission (IEC) just released a new international standard titled: "Overhead lines - Method for fatigue testing of conductors". IEC 62568. Edition 1.0 2015-07. www.iec.ch . It closely follows previous CIGRE and EPRI publications on this topic:
CIGRE SC B2 WG11 TF7 "Fatigue Endurance Capability of Conductor/Clamp Systems - Update of Present Knowledge" CIGRE TB 332, 2007, Paris.
Single strand cable bending, stick-slip, analytical models require that a choice be made between two contact modes between adjacent wires: either radial (between layers) or lateral (between same layer wires). In most recent models (e.g. Papailiou’s) radial contact is selected. A “lateral contact” model has been presented by Panetti in 1944 and can be found in the proceedings of the Turin Royal Academy of Science. A translated version from Italian is proposed in the attached file.
Some 2014 papers on the mechanics of helical strands: cables and electrical conductors