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About Renga@MFRC

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  1. Hello, I would like to export the residual stress results from a forming simulation in Hyperform to carry out a structural analysis of the formed part in OptiStruct. Could some one please share a tutorial based on this workflow? Thank you in advance. Regards,
  2. Hello Lutz, Was eager to know if this bug has been fixed? I would like to use negative values for design variables but I keep getting the message "initial value not included in values". Because of this, I am not able to go to the next step. Your response would be appreciated. Regards, Renga
  3. If you want to use symmetry, you don't have to model the full geometry as you have done. As I have indicated in my picture, please model only a sector of the cylinders (Lower die, work piece) and cone (upper die). Then you have to select the 2 planes which go along the height dimension of the work piece. The planes that you should chose on the work piece are numbered as 1 and 2 in the below picture. (Only work piece and lower die shown in this picture) Refer to AFDEX Manual in the installation folder for more details.
  4. Hello, I assume the cylinder in rose color denotes your work piece. Then you should model only a sector of the work piece and dies (for example 30, 45 or 60 deg) and then select the planes of symmetry like shown in the below picture. Regards, Renga
  5. Hello everyone, AFDEX MAT is the material identification module which is used for obtaining flow stress information from the load versus elongation data which is got from tensile/compression tests. Figure 1: Material identification using AFDEX MAT Figure 2: Fracture prediction in tensile test To know how this algorithm works, you can read this. Do get in touch with our technical support team (r.sekar@afdex.com) for further specific details. Cheers from AFDEX Support team!
  6. Hello everyone, Cross wedge rolling is a plastic deformation process carried out at elevated temperatures to exploit the advantage of lesser deformation forces. The initial work piece is mostly cylindrical in shape and is deformed into stepped parts by the tangential movement of dies around the work piece. The process boasts of high efficiency, ease of automation and equipment simplicity. The automotive industry is getting more creative regarding the application of cross wedge rolling. Below are some snapshots of a cross wedge rolling process simulation using AFDEX. Do get in touch with our technical support team (r.sekar@afdex.com) for further specific details. Cheers from AFDEX Support team!
  7. Hello everyone, Self-piercing riveting is a high-speed single-step technique for joining sheet material. Below is an example of the self-piercing riveting process simulation using AFDEX. The rivet and the two sheets were considered as work piece in the simulation and a binder force was applied on the sheets during the riveting. Get in touch with our technical support team (r.sekar@afdex.com) for further details. Cheers from AFDEX Support team.
  8. Dear Forum users, The AFDEX predictions of a chevron crack which occurs during the extrusion process is presented and the results are compared with experiments for validation. Cheers from Support Team !
  9. Hello Forum users, An automatic multi-stage precision cold forging process of a yoke was simulated with emphasis on springback phenomenon using an elastoplastic finite element method. The results are discussed below. Figure 1. Yoke to be studied (cold forging) Figure 2. Process design and simulation result of the 6-stage cold forging process Figure 3. Returning process of the punch in Stage 5 – Contours of nodal velocity shown in the picture Figure 4. Measurement of distances between measuring points at ears before and after the punch returning process It was observed that the AFDEX predictions deviated from the experiment values by 16% in this example. Cheers from AFDEX Support Team !
  10. Dear Forum users, Here is another example of 2D and 3D combined simulation in AFDEX. The above figure compares the AFDEX predictions with the experiments. This is an automatic four-stage cold forging process for a high-strength bolt. The metal flow lines can also be visualized. Cheers from AFDEX Support Team!
  11. Hello Vivian, Yes. It is possible to create a new material and use it for your simulation if you have the material properties. You would be needing the material module “AFDEX-MAT” for doing this. This module can be executed from the installation folder. In terms of input data, for defining a material, you should be having the plastic deformation information. This can be load vs. elongation data, engineering stress vs. engineering strain data or true stress vs. true strain data. You would also be asked to enter the diameter and gauge length of the specimen that you had used during the tensile/compression test. If this information is not available, you should be choosing the "Hollomon model" to define the material. But this topic is a separate post in itself. I hope I have answered your question. Cheers from AFDEX Support Team !
  12. You are welcome. Please do get in touch if you need more information.
  13. Hello dear forum visitors, AFDEX 3D can read AFDEX 2D results files either directly or by means of a simple connecting program, and thus 2D and 3D combined simulations can easily be carried out. Of course, the 2D results can be viewed by the 3D post-processor with more powerful graphics functions. Figure 1. shows the predictions of a five-stage precision cold forging process involving one piercing stage and a final three-dimensional stage, obtained by using the 2D and 3D combined simulation capability with minimum user intervention (i.e., with only an initial run and one connection run). Figure 1: 2D and 3D combined simulation - AFDEX It should be noted that this capability is especially efficient for fastener forming process simulation. The 2D and 3D combined simulation is strongly recommended for enhancing computational time, solution reliability, and engineering productivity when relatively few stages are three-dimensional. So it's time to use your resources smartly. Cheers from AFDEX Support team!
  14. Hello everyone, The figures below compare the AFDEX predictions and experiments of a bevel gear manufacturing process composed of an enclosed die forging stage and a consecutive sizing stage. As this is a representative process in near-net shape manufacturing, a precision simulation is required. Figure 1: Process 1 - Enclosed Die Forging Figure 2: Process 2 - Sizing Figure 3: Enclosed Die Forging - Comparison Figure 4: Sizing - Comparison Cheers from AFDEX Support Team!
  15. Damage models play a decisive role in predicting the fracture phenomena that occur during metal forming or material testing. They may be classified into many categories based on energy, pore-growth micromechanics, porous material and continuum-damage mechanics. AFDEX supports the following damage models as shown in Figure 1 in the current version. 1. Cockroft & Latham Normalized 2. McClintock 3. Brozzo, Deluca & Rendina 4. Oyane, Okimoto & Shima 5. Rice & Tracey 6. Freundenthal Figure 1: Damage models in AFDEX For predicting the crack propagation, AFDEX uses an improved node-splitting technique in the quadrilateral mesh system. Figure 2 shows the history of the fracture formation made using the Brozzo et. Al damage model. It can be observed that the early crack propagates horizontally up to two thirds of the radius of the material. The crack growth is then finalized in the inclined direction. Figure 2: History of fracture formation by the Brozzo et al. damage model A detailed view of the fracture surfaces predicted using different damage models is presented in Figure 3. Figure 3: Detailed view of Fracture surfaces All the major damage models predicted acceptable solutions in terms of the slope of the tensile load drop in the fracture region. It can be observed from Figure 4 that the Freudenthal damage model came closest to the experiments. Figure 4: Load vs. Elongation curve based comparison For more details, reading the literature in the link below is recommended. http://msjoun.gnu.ac.kr/pub/paper/2014/Evaluation of Damage.pdf Cheers from AFDEX Support Team !
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