In Excel I typed drawing stress formula as:
σy * (3.2/( Δ + 0.9)) (α+ μ) = 572,776
σy * ((3.2/ Δ ) + 0.9) (α+ μ) = 51,760
|
Draw Stress
|
51,760
|
$B$31 * (3.2/$B$21) + 0.9) * ($B$13+ $B$25)
|
|
|
200,000 * 1.312 * .1972
|
|
|
|
|
Pounds Force
|
|
Draw Stress * Area
|
|
|
51,760 * 3.799
|
|
Draw Force
|
196,657 lb
|
=$B$40 * $B$17
|
Thanks, you were right about the error.
I have the updated 14A now, thanks Scott Henry.
Can I use the actual Yield as the Average flow stress?
------------------------------
David Kirchner
COO
High Performance Alloys, Inc
Tipton IN
(765) 945-8230
------------------------------
Original Message:
Sent: 12-15-2023 13:36
From: David Coulston
Subject: Draw Bench math
David,
I am a little bit confused by this calculation:
| σy * (3.2/ Δ ) + 0.9) (α+ μ) |
I am probably not grabbing the right numbers... but when I plug values in, I get an answer that is about 1/10 of the 572,776 value you ended up with.
Another Dave
------------------------------
David Coulston
Niles MI
Original Message:
Sent: 12-14-2023 18:28
From: David Kirchner
Subject: Draw Bench math
| Material Handbook 9th Editition, Volume 14 | |
| Forming and Forging, pg 331 | | |
| Wire, Rod, and Tube Drawing | | |
| | | |
| Aproach Angle | Δ | | |
| deformation zone | Δ | ( α rad/γ)*(1+(1-γ)^.5 ) ^2 | |
| | | |
| die angle | α | The half angle in radians | |
| 5 | (Deg/180)*3.14156 | typical 5-15 degree half angles |
| D0 | 2.25 | in | |
| D1 | 2.20 | in | |
| | | |
| α | 0.0872222 | B12/180*3.14 | |
| | | |
| reduction | γ | 1 - (A1/Ao) | |
| A0 | 3.9740625 | 3.14 *$B$20*$B$20/4 | |
| A1 | 3.7994 | 3.14 *$B$21*$B$21/4 | |
| | | |
| γ | 0.0439506 | 1-($B$18/$B$17) | |
| | | |
| Δ | 7.7627778 | ( α rad/γ)*(1+(1-γ)^.5 ) ^2 | |
| | | |
| Minumum draw stress | Δmin | =4.9(μ / (LN(1/(1-γ))))^.5 | |
| coefficient of friction | μ | | |
| μ | 0.11 | guess | |
| Δmin | 7.6656377 | | |
| | | |
| draw stress | σd | | |
| avg flow stress | σa | average work per volume | |
| Yield Strength | σy | psi | |
| actual ys | 200,000 | lb/in*in | |
| | | |
| drawing stress ratio | Σ | [(3.2/Δ )+0.9](α+ μ) | Another Book 5.13 |
| σd | σy * (3.2/ Δ ) + 0.9) (α+ μ) | |
| psi Draw Stress | 572,776 | $B$38 * (3.2/($B$24 + 0.9)) * ($B$16+ $B$33) |
| | | |
| Pounds Force | | Stress * Area | 572,776 * 3.799 |
| Force | 2,176,205 | =$B$41 * $B$19 | |
| Draw Bench is called 100,000 pound? | |
Can the Actual tested Yield be used in these calculations?
Where do find where my math went wrong?
------------------------------
David Kirchner
COO
High Performance Alloys, Inc
Tipton IN
(765) 945-8230
------------------------------