What are the situations of broken wire of steel wire rope?

1. Local accumulation and broken wire of steel wire rope

If the broken wires of the steel wire rope are close together to form local aggregation, the steel wire rope shall be scrapped. If the broken wires are gathered in the rope length range of less than 6D or in any rope strand, the steel wire rope shall be scrapped even if the number of broken wires is less than the value specified in the standard. Local accumulation of broken wires on the surface of steel wire rope is often caused by fatigue failure.

2. Broken wire at Valley of steel wire rope

The broken wire in the valley of the steel wire rope usually occurs on the multi-layer strand steel wire rope. When the steel wire rope bears the external load, the valley position where the inner steel wire rope and the outer steel wire rope contact each other will be squeezed, and the steel wire rope in the valley position will be subjected to alternating stress for a long time. The broken wire in the valley develops from inside to outside. If the broken wire occurs in the valley of the steel wire rope, the internal steel wire has often suffered serious losses. When one or more broken wires in the valley are found in one lay distance, the steel wire rope shall be scrapped

3. Broken wire inside the steel wire rope

Internal broken wire is the most common on multi-layer non rotating steel wire rope. Multi layer non rotating steel wire rope is made of inner and outer strands twisted in the opposite direction in the steel wire rope, which has good low rotation under tension. Due to the opposite twist direction of the inner and outer layers of rope, the layer strands are in point contact state. When the steel wire rope bears the load, there is a great extrusion force and friction between the strands, and the extrusion force and friction force of the inner layer strands are the largest. The broken wires inside the steel wire rope are often difficult to find with the naked eye. When the outer steel wire is not damaged, a large number of broken wires are generated inside, and the resulting accidents are difficult to predict.

The scrapping standard of broken wire of steel wire rope is based on the requirements in gbt5972-2009 maintenance, maintenance, installation, inspection and scrapping of steel wire rope of heavy machinery. The relevant scrapping standards are given in the form of table. If you check the table, you will find that you can't understand it, and there are many concepts involved, such as "interactive twist", "same direction twist", "twist distance", etc. at the same time, the working level and length range should be considered. Many safety managers, especially those of construction units, will be deterred.

Make the specification update feasible and make the front-line operators and managers more acceptable and understandable. The work of safety managers still has a long way to go.