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.
I´m doing a plastic collapse evaluation as per API 579-1 Appendix B1, and one of the load cases is Earthquake loads. 579 refers to ASCE 7, which for tanks refers to API 650 Appendix E. The approach in 650 is a static equivalent lateral force seismic analysis where you find equivalent lateral forces and moments according to some likely earthquake spectrum. It seems that what you do is apply these at the top of the tank shell, which mimics the overturning and shear behavior, assuming the tank doesnt slide from inertia.
Hello All,
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.
Hello, Everybody, who is studing reservoir geomechanics,
With the availability of different brands and grades of cables in the market, it can be pretty challenging to narrow down the options to a few good ones. As with several other things related to wires, a high price tag or big brand name doesn’t actually help in making the right selection. Instead, one has to look out for particular characteristics and specifications for picking the right cable.
Some 2014 papers on the mechanics of helical strands: cables and electrical conductors
One approach to helical strand (cable or overhead electrical conductor) bending analysis puts the emphasis on friction rather than on elastic curved rod behavior. Based on Coulomb’s laws of friction, it leads to stick-slip models where strand bending stiffness varies with imposed curvature (Papailiou, 1995). Such an approach can be traced back to a Ph.D. thesis by H. Ernst, in 1933. This work is in fact often referred to in cable analysis reports. An English translation (with a short presentation) of the dissertation analytical part is attached.
