Letters

摘要

I read of the elevator-cable innovation in "High-Rise Elevator Called 'Breakthrough Technology' " (ENR 6/17/13 p. 12). I have accumulated considerable experience assuring that bridge and building cables in tension can safely withstand millions of cycles of repetitive tension, bending and fretting loads. These doubtless will play a role in safety and serviceability of the carbon-fiber-reinforced-polymer-based, weight-saving belts proposed for the elevator systems. CFRP cables have been considered and evaluated in laboratory settings and installed on a handful of structures, but not in a primary-load-path setting, to my knowledge.