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  1. MechEngineerNT

    Non-Linear Static Structural to Explicit Dynamic Environment (Material Properties Issue)

    I ran the Johnson cook model in a static environment and the results were a bit weird. I thought it took into account permanent plastic deformation, however, the flange of the crimp popped back after the roll die cold-formed it. The crimp should've clearly been deformed. Johnson cook is meant...
  2. MechEngineerNT

    Non-Linear Static Structural to Explicit Dynamic Environment (Material Properties Issue)

    Thanks, L K. I don't have a good understanding of the Johnson-Cook material model for 7075-T6 (material I'm analyzing). I've done some preliminary research and have found some constants online (attached), but can't seem to find some constants ansys is looking for. I've found Ansys has some...
  3. MechEngineerNT

    Non-Linear Static Structural to Explicit Dynamic Environment (Material Properties Issue)

    Hi Guys, I'm running a Primer crimp simulation. In step one, I'm applying a displacement to a roll die and plastically deforming a crimp on a primer. From there, I want to apply a pressure trace to the internal faces of the primer to see if it holds. I've been running this simulation in the...
  4. MechEngineerNT

    Pendulum test

    Hey Guys, I'll be running a pendulum test to test gun recoil. The platform is around 100 lbs and will be supported by 2 steel bars about 8 feet long and 20lbs each. Would it be safe to ignore the weight of the metal arms because they are so long? Thanks, Alex
  5. MechEngineerNT

    Crimp Die for 45 Primer and Cartridge -- FEA non-linear Analysis not matching with Real life results

    Thanks NRP99. That was very useful. Did what you advised, but still got similar results, still failing, however FOS to ultimate is around 0.87 using Equivalent Von Mises now. I'm wondering if I should use a different failure criterion. The upper portion of the crimp is in compression, couldn't...
  6. MechEngineerNT

    Crimp Die for 45 Primer and Cartridge -- FEA non-linear Analysis not matching with Real life results

    Hey Guys, I'm running a quasi-static non-linear FEA in Ansys trying to simulate crimping a primer into the cartridge using a die crimp tool. In short, the crimping operation works in real life (80 units tested), to which I've decided to try to simulate. However, the result of the simulation...
  7. MechEngineerNT

    FEA die crimp non linear quasi static

    Yeah, have already done that from the start (large Deflection). Simulation would crash if large deflection wasn't activated. I put in a friction coefficient of around .2 (aluminum to brass), however it didn't make any real impact. --Alex
  8. MechEngineerNT

    FEA die crimp non linear quasi static

    Is it possible the pieces in real life are being work hardened by the crimp, and thus attaining a higher ultimate strength?
  9. MechEngineerNT

    FEA die crimp non linear quasi static

    If you take a look at the video I posted, all the elements in red are above .88-.99 ult FOS to von mises failure criterion.
  10. MechEngineerNT

    FEA die crimp non linear quasi static

    Yeah, I'm trying to understand what benefit applying a force would have as opposed to a displacement value?? They should achieve the same result. And yes, I'm using True -stress strain curve, not the engineering stress. It is a substantial amount of elements, however, they are very marginal--...
  11. MechEngineerNT

    FEA die crimp non linear quasi static

    Thanks for the reply, L K. I'm very concerned about the stresses the crimped material exhibits when the die comes down and pinches it to the primer. Some portions of the material are above it's Von Mises Maximum ultimate tensile strength when it undergoes the crimping process (as shown in red)...
  12. MechEngineerNT

    FEA die crimp non linear quasi static

    Hey Guys, I'm running a quasi-static non-linear FEA in Ansys trying to simulate crimping a primer into the cartridge using a die crimp tool. In short, the crimping operation works in real life (80 units tested), to which I've decided to try to simulate. However, the results of the simulation...
  13. MechEngineerNT

    Crimp Die for 45 Primer and Cartridge -- FEA non-linear Analysis not matching with Real life results

    Hey Guys, I'm running a quasi-static non-linear FEA in Ansys trying to simulate crimping a primer into the cartridge using a die crimp tool. In short, the crimping operation works in real life (80 units tested), to which I've decided to try to simulate. However, the results of the simulation...
  14. MechEngineerNT

    Measuring Pressure---Casting a composite material

    link Your file's link is: http://files.engineering.com/getfile.aspx?folder=e8f5ad54-61cc-40a6-ab54-f5b70e962c97&file=photo_(1).JPG http://files.engineering.com/getfile.aspx?folder=e8f5ad54-61cc-40a6-ab54-f5b70e962c97&file=photo_(1).JPG
  15. MechEngineerNT

    Measuring Pressure---Casting a composite material

    Hi All, I'm currently working on a project that involves measuring pressure of a material being cast. A test cast was designed in which threaded holes were machined in order to accommodate pressure transducers; which act as a part of the cast wall when inserted. I am interested in measuring the...
  16. MechEngineerNT

    Casting a Composite material characterization

    Sorry, bad grammar. I've been getting higher pressure readings on the OD of the part as compared to the surface of the part. We are applying a pressure only to the top surface.
  17. MechEngineerNT

    Casting a Composite material characterization

    Hi Guys, I currently investigating a casting procedure that the company i have been working for has had a lot of issues with. So I outfitted this with pressure transducers and load cells. I applied to load cells on the top and bottom of the cast, and pressure transducers on the OD of the cast...
  18. MechEngineerNT

    Compressive Pre-Load (bolted member)

    BrianE22, This is a piston the is operated by a hydraulic system. The force is coming from the top down, which is 1 load path thru the pressure trandsucer.
  19. MechEngineerNT

    Compressive Pre-Load (bolted member)

    Tbuelna, yes i have recently changed the design because of this. So know to get an accurate load cell measurement i must subtract the weight of the piston.
  20. MechEngineerNT

    Compressive Pre-Load (bolted member)

    ALso, please ignore symbols, these are just NX mating symbols. THanks,

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