Searching for any lead on realistic cord mechanics

In summary, this physicist is trying to understand how a multishafted cord is transferred force and has run into many difficulties. He is looking for help from others and recommends reading two papers. The first paper discusses how to transfer force without reflection and the second paper is about control cables in aircraft.
  • #1
Erandom
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0
Hi all, I'm a physicist, and I'm now trying to understand and model a problem with a multishafted cord, being pulled from one side in order to transfer force. The cord has its own elastic properties (elongation, bending etc.), it goes through several pulleys with friction, and most likely its mass is not negligible.

Point being, from the physics perspective, everything I've neglected in my BSc, came back for revenge.Can anyone point me in a direction of research and models on this topic?

I tried looking for articles and calculations for force transfer on cranes (assuming that in long ropes the elastics are important). I searched for equations in the field, but only found the Capstan Equation. I have found very little helpful materials until this moment.

Any lead, book, suggestion or even subject name in English will be very helpful at this point.Thank you very much in advance,

Erandom
 
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  • #2
Cable and cordage, rope/cable lays may get you a toehold into what you're after.
 
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  • #5
I should remind you of the necessity of keeping tension in your cords to maintain the speed of sound. Cords break when the ends of the system move independently and the speed of sound in the cable permits transmission line characteristics to come into play.

I have not read the references posted, but control wire and cord systems are transmission lines with impedance mismatches at the pulleys. To transfer energy without reflection requires matched impedances. Local reflection of energy has been used to cut thread when stitching agricultural bags.

Resonance systems should be avoided as the stored energy is either destructive or rapidly lost.
 
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  • #6
Thank you for the extra input. My system is not in full tension (at least when I start pulling). It's interesting whether one can exert force through a semi-rigid cord while there are still DOFs that can be streched and get to higher tension.
Your comment about resonance is very important, but I find it very hard to calculate the frequencies when I don't know the frictions coefficients or the stiffnesses. Maybe I should just try to find this empirically.

Thanks again,
 
  • #7
Control cables in aircraft are/were arranged in a closed loop as a differential pair. They are adjusted and pre-tensioned so as to reduce actuator delay and raise the frequency of oscillation.You might consider using two cables in a similar closed loop.

Google 'analysis of control cables' and amongst other offerings you will find;
“Dynamic Analysis And Control Of Cable Driven Robots With Elastic Cables”.
http://www.tcsme.org/Papers/Vol35/Vol35No4Paper6.pdf
 

Related to Searching for any lead on realistic cord mechanics

1. What is the purpose of searching for a realistic cord mechanics?

The purpose of searching for realistic cord mechanics is to understand and replicate the behaviors and movement of cords in real-life situations. This can be useful in various industries such as engineering, robotics, and animation.

2. What are some common challenges in simulating cord mechanics?

Some common challenges in simulating cord mechanics include accurately capturing the flexibility and elasticity of cords, accounting for friction and tension, and determining the appropriate material properties.

3. What techniques are commonly used in studying cord mechanics?

Some commonly used techniques in studying cord mechanics include mathematical modeling, computer simulation, and physical experiments using different materials and setups.

4. How can the understanding of cord mechanics be applied in real-world scenarios?

The understanding of cord mechanics can be applied in various real-world scenarios, such as creating more realistic animations and special effects, improving the design of mechanical systems, and enhancing the functionality of robotics and prosthetics.

5. What advancements have been made in the study of cord mechanics in recent years?

In recent years, advancements in technology and computational methods have allowed for more accurate and complex simulations of cord mechanics. Additionally, there has been a focus on studying the behavior of cords in different environments and under varying conditions.

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