calculation molding forces

[franciDK]

Bye to all,
I would need a formula (simple and analytical, then approximate) that allows me to calculate the molding force in two cases:
- bulk molding
- moulding of sheet metal

In the first case the most used formula is f=k*re*a, where k is a coefficient that takes into account the complexity of the geometry, king is the elastic limit and to is the area on the bava plane.
In the second case, I don't know what fish it is. . .

do there exist methods that allow this calculation approximate, and perhaps that they also take into account the starting material?

Thank you in advance!! !

 

[Counterblow Hammer]

Bye to all,
I would need a formula (simple and analytical, then approximate) that allows me to calculate the molding force in two cases:
- bulk molding
- moulding of sheet metal

In the first case the most used formula is f=k*re*a, where k is a coefficient that takes into account the complexity of the geometry, king is the elastic limit and to is the area on the bava plane.
In the second case, I don't know what fish it is. . .

do there exist methods that allow this calculation approximate, and perhaps that they also take into account the starting material?

Thank you in advance!! !

for sheet metal there is no problem: the topic has been developed sufficiently and the various formulations are present now on all the serious manuals that treat sheet metal stamping.

regarding mass deformation... Happy birthday!
Unfortunately in this type of processing in addition to the material and at its temperature it is necessary to take into account the speed of deformation (and therefore the forces that you find operating with a press are completely different from those that you will find using a millet), the degree of deformation that the initial solid must undergo (you consider that print directly from solid requires a force greater than using intermediate sketches), from the geometry of the channel of bava (oftenor and relationship length/of) .
if you want to deepen the topic I suggest you get the book on the hot stamping of the giusfredi (hot metal plastics, etas kompass, 1967), or the Altan article for the calculation of the stamping force on a press (a practical method for estimating forging load with the use of a programmable calculator, 1980) or thomas & bannister article dealing with various formulations for the estimation of force in forging processes (the accuracy of forging load estimation in drop forging, 1976).

I conclude by making you observe that the formulation reported in the giusfredi is quite used in the industrial field, while that of Altan has made proselytes among the forgiers of American school. it is clear that both formulas need common sense in using them as in these estimates an error of 20÷25% can be in some cases considered acceptable.
if I can give you advice however I would say that the formula of the jesters is good for all seasons, especially when you are in the workshop and you need a reference also to spans; the other formula needs a little more calm in being applied, but it has the advantage that provides a little more precise results.


for any clarification are available. . .