How to calculate blank holder force with AutoForm

1. For the setting of drawing blank holder force in AutoForm, many people often set it incorrectly and have problems in understanding. Let's talk about his setting method. At the beginning of the first calculation, the blank holder force can be set to P = 3Mpa, but after the adjustment, it should be set to tonnage according to the calculated blank holder force, and try to make the blank holder force less than 80% of the actual press maximum outer slider force (double action) or maximum lower air cushion force (single action), so as to ensure the authenticity and reliability of the calculation results!! If the calculated blank holder force is greater than 80% of the actual press maximum outer slider force (double action) or maximum lower air cushion force (single action), other parameters, such as sheet size / drawbead strength / drawing model, need to be adjusted to rece the blank holder force. Otherwise, even if the simulation result is the best, it can not be realized on the actual press.

2. Look at the loading process of force in process data in results, thank you

3. The tensile strength of Q235 is 460Mpa,
F = Lt σ B = 327 * 8 * 460 = 1203360n
about 120.336t
take the safety factor of 0.7, take the press of more than 172t, according to the priority number system:
1, open press can buy 200t punch press, model: j21-200, but in fact, it is also capable on the machine tool of 160t, but it may cause bad influence on the machine tool
2. Closed single point press is 200 tons, model: j31-200,
3. Four column universal hydraulic press is 200 tons, namely y32-200

5. I don't have this software on my computer, so it's not easy for you to understand it,

6. In the field of stamping analysis, especially in the automobile and die instry, it is the preferred CAE analysis software. This is mainly e to the speed of AutoForm calculation, which is several times of DYNAFORM and pamstamp, but the accuracy is not as good as DYNAFORM and pamstamp. Therefore, large companies (including automobile companies and die companies) generally have one of DYNAFORM or pamstamp. At the end of the day, AutoForm is basic anyway.

7. 1. Blanking force:
F = LT σ B
L: length of trimming line
t: material thickness
σ b: The tensile strength of material
generally, the blanking force is 60-70% of the nominal pressure of the machine tool
2. Drawing force:
generally speaking, the drawing force is difficult to calculate. In the past, the drawing force and blank holder force can only be estimated by the experience of technicians, and then the punching machine:
approximate empirical formula:
blank holder force: F = AP
P: Unit Blank Holder Force: 2.5-3 Q235 as an example, unit MPa)
A: blank holder area
drawing force: F = KLT σ B (cylindrical part)
k: coefficient: 0.9-0.7, the simpler the part is, the lower it is
L: punch peripheral length
t: material thickness
t: material thickness σ b: The tensile strength of materials is
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but it is impossible to accurately calculate the drawing force of parts, especially for parts with complex shape. However, a rough value can be obtained by finite element simulation, such as AutoForm, DYNAFORM, etc., which can be said to be relatively close to the reality. Generally speaking, when choosing the press, The total drawing force (blank holder force + drawing force) is about 80%. Of course, you can get higher.

8. First set the flanging sequence in geometry generator, then set the drawing sequence, and then set the simulation parameters in proses generator process generator. The flanging sequence tool you want to set can be mapped in the process generator

9. The first warning is that the penetration of sheet metal occurred in 1999. It should be a problem in the shaping process. Carefully check the animation process and adjust the parameters. The second warning can be ignored, which means that the blank holder will automatically load the blank holder force to achieve the pressing state. When the setting force is not enough, it will appear.