Calculating Resistivity across a mesh sheet

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Discussion Overview

The discussion revolves around calculating the resistivity of a titanium grade 1 mesh sheet, specifically focusing on its geometry and electrical properties. Participants explore various aspects of the mesh, including its dimensions, material properties, and potential applications, while seeking guidance on the calculation methods involved.

Discussion Character

  • Technical explanation
  • Exploratory
  • Debate/contested

Main Points Raised

  • One participant states the resistivity (ρ) for titanium as 4.3x10^-8 ohm x m and provides dimensions for a 1x12 inch mesh sheet.
  • Another participant seeks clarification on the geometry, questioning whether the mesh is a solid sheet or a mesh of wires and asking for a sketch.
  • There is a discussion about the thickness of the mesh and how the wires are bonded at crossings, with questions about the resistance of these bonds.
  • One participant suggests that if the current flows vertically, horizontal connections can be ignored, and proposes combining parallel vertical resistances.
  • A later reply presents a calculation for the resistance of columns in the mesh, indicating a method for determining total resistance based on the number of parallel columns.
  • Participants express uncertainty about the application of the mesh and how voltages will couple into it, with one participant asking for clarification on the intended use.

Areas of Agreement / Disagreement

Participants have not reached a consensus on the geometry and application of the mesh, and multiple competing views remain regarding the calculation methods and interpretations of the mesh's properties.

Contextual Notes

There are unresolved questions about the specific application of the mesh, the nature of the connections, and the assumptions regarding the material properties and geometry. The discussion includes various interpretations of how to approach the calculations.

AlexTheFirst
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Hi everyone!

I'm trying to figure out how to go about this in calculating resistivity of a titanium grade 1 mesh. From what I know the ρ for titanium is 4.3x10^-8 ohm x m. The mesh will be a 1x12inch sheet wrapped cylindrically end to end. Here are the stock values including a change in area. Les also say the temperature of the material is 20°C and grade 1 is equal to 99.9% pure so let's just round that to 100% and ignore impurities.

Area: 12x12inches
Wire diameter: 0.0020inches = 0.0508mm
Width Opening: 0.0080 inches = 0.2032mm
Wire Mesh (wires/in): 100 x 100
% open Area: 64%
ρ for titanium is 4.3x10^-8 ohm x m

I was thinking of using
R=(ρ)(Length)/(cross section area of wire)

im not an electrical engineer, so any guidance what's so ever would be a great help. Thank you everyone.
 
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also if you need any other values, please let me know and I'll try to get them to you.
 
AlexTheFirst said:
Hi everyone!

I'm trying to figure out how to go about this in calculating resistivity of a titanium grade 1 mesh. From what I know the ρ for titanium is 4.3x10^-8 ohm x m. The mesh will be a 1x12inch sheet wrapped cylindrically end to end. Here are the stock values including a change in area. Les also say the temperature of the material is 20°C and grade 1 is equal to 99.9% pure so let's just round that to 100% and ignore impurities.

Area: 12x12inches
Wire diameter: 0.0020inches = 0.0508mm
Width Opening: 0.0080 inches = 0.2032mm
Wire Mesh (wires/in): 100 x 100
% open Area: 64%
ρ for titanium is 4.3x10^-8 ohm x m

I was thinking of using
R=(ρ)(Length)/(cross section area of wire)

im not an electrical engineer, so any guidance what's so ever would be a great help. Thank you everyone.

Welcome to the PF.

Your geometry is not entirely clear to me. First you talk about a metal sheet, then you wrap it around a cylinder (?) and then there are some wires attached somehow? Can you post a sketch or some other way of illustrating what you are making? Also, how thick is the sheet? What are the wires made of?
 
1V4XVAM.jpg
Its a mesh sheet made out of titanium. The goal is to wrap one end and connect it to the other to create a cylinder.
IJEa1p7.jpg

The thickness of the mesh is 0.0020 inches. I
Does that help?
 
Oh, it's a mesh of bare wires, not a solid sheet. Got it. And the wires are made of titanium? How are they bonded at the crossings? What will be the resistance of the bonds?

Also, how will any voltages be coupled into this? Can you say what it will be used for? Which way will currents flow through this mesh?
 
The mesh is made of titanium. Heres what it more or less should look like, albeit finer.
akKRlgJ.jpg

From what I know its a solid sheet that's been perforated to make it a mesh.
I can't really say what it'll be used for, but the current should be flowing upward.
As for coupling, I'm not entirely sure what you mean by that. Do you mean where the voltage energy will be going to once it passes through the wire mesh? then it will be wrapped around a porous wick.
Also thank you for being so patient.
 
AlexTheFirst said:
From what I know its a solid sheet that's been perforated to make it a mesh.
Ah, that makes it easier.
AlexTheFirst said:
I can't really say what it'll be used for, but the current should be flowing upward.
If the current will be flowing vertically, then you can ignore the horizontal connections. Just combine all of the parallel vertical resistances.
AlexTheFirst said:
As for coupling, I'm not entirely sure what you mean by that.
If you were using this mesh for E-field shielding, I was asking about how the E-field (or EM wave) would be coupling into it. But it sounds like it is not being used for EM shielding?
 
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Titanium mesh connection types.jpg

In my opinion, if you'll supply voltage from top to bottom using tight fitted rings[see connection type A], I should agree with berkeman.

Then there are 1200 parallel columns [12/0.01] each one of 12 inches long and 0.002 inches diameter.

Each column resistance =length[m]*rotitanium[ohm.mm^2/m]/area[mm^2]

Rcolumn=12*25.4/1000*0.043/ 0.00202683=6.4665 ohm

Rtotal=Rcolumn/1200=6.4665/1200=0.00538871 ohm

However, if the outgoing wire is connected with a column only[see connection type B] the calculation is more complicated.
 
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