Did a Shear-Tensile Failure Cause the Wire Rope Accident?

In summary, the conversation discusses a photograph of a wire from a 7 strand wire rope made of aluminum that was involved in a car accident. The wire appears to have been sheared diagonally, but it is unclear if it was due to tension or wear over time. The photo can be viewed on Flickr by searching "national electrical code" in quotes. It is difficult to determine the cause of the failure without knowing the events leading up to it.
  • #1
zerodish
9
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I have been photographing wires hanging from utility poles that have tangled with and caused automobile accidents. One of these is a puzzle the detail shows a wire from a 7 strand wire rope made out of aluminum. It was too dangerous at the time to anything but drag the wire out of the road and the wire has been removed by the utility. http://www.flickr.com/photos/78934859@N04/12562669533/in/photolist-k97XYz-cabvfq-euZ4FC-hEtawu
 
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  • #2
Can't you just upload the pic here ? to view the pic one needs to sign up for flickr...
 
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  • #3
The wire appears to have been sheared diagonally.
If it had failed under tension I would expect a ragged end or a thinning.

It is possible that it was worn over time against an abrasive surface.
Maybe swinging or vibrating in the wind.
 
  • #4
Here is the photo you can view it on flickr by searching "national electrical code" in quotes.
 

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  • #5
Definitely not tensile failure. I concur with Baluncore. You would see a thinning of the material at the point of break. Possibly broken when it was driven over and dragged along the roadway.
 
  • #6
It's really tough to say...
(1) these cables are wrapped in a 7 cable bundle, most often twisted to maintain shape.
(2) Power cables are in tension but they are catenaries, this, coupled with (1) could cause some very odd shearing action, especially coupled with other loads (wind, entanglement, etc)

There's not much thinning in shear-tensile failures in wire rope. That's a really long "shear plane" (if that's what it is) though...

These factors make it difficult to tell what had happened. Do you know the events which led up to this failure?
 

1. What is a tensile failure?

A tensile failure is a type of mechanical failure that occurs when a material breaks under tension or pulling forces. It is commonly seen in materials such as metals, plastics, and composites.

2. How do you determine if a failure is due to tension?

To determine if a failure is due to tension, engineers and scientists use various methods such as stress analysis, strain measurements, and failure analysis techniques. They may also conduct experiments to simulate the conditions that led to the failure.

3. What are the common causes of tensile failure?

The common causes of tensile failure include excessive stress or strain, material defects, poor design, and environmental factors such as temperature, humidity, and corrosion. In some cases, a combination of these factors may lead to a tensile failure.

4. How can tensile failure be prevented?

Tensile failure can be prevented by using materials with appropriate strength and properties for the intended application, ensuring proper design and installation, regular maintenance, and avoiding exposure to harsh environments. It is also important to conduct periodic inspections and testing to detect any potential issues before they lead to failure.

5. Can tensile failure be predicted?

Yes, tensile failure can be predicted using various analytical and computational methods. Engineers and scientists use mathematical models, computer simulations, and testing data to predict the behavior of materials under different loading conditions. This allows them to identify potential failure points and make design changes to prevent tensile failure.

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