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Metal Forming

FAQ's related to metal forming simulation in LS-DYNA
Article During the forming analysis I found that some elements in the blank became distorted. How can this problem be solved?
http://www.dynasupport.com/faq/metal-forming/during-the-forming-analysis-i-found-that-some
Article After the trimming process, some of the elements in the blank mesh have become distorted around the trim line. How can this be avoided?
http://www.dynasupport.com/faq/metal-forming/after-the-trimming-process-some-of-the-elements-in
Article Can I arbitrarily pick the nodes to constrain for a springback analysis?
http://www.dynasupport.com/faq/metal-forming/can-i-arbitrarily-pick-the-nodes-to-constrain-for
Article Can you advise how to improve the speed in the forming analysis?
http://www.dynasupport.com/faq/metal-forming/can-you-advise-how-to-improve-the-speed-in-the
Article Can you explain the failure behaviors that occur in sheet metal forming?
http://www.dynasupport.com/faq/metal-forming/can-you-explain-about-the-failure-behaviors-that
Article Do I have an easier way to define the velocity curve?
http://www.dynasupport.com/faq/metal-forming/do-i-have-an-easier-way-to-define-the-velocity
Article Do I have to consider the thickness of the blank?
http://www.dynasupport.com/faq/metal-forming/do-i-have-to-consider-the-thickness-of-the-blank
Article Do I have to consider the thickness of the rigid bodies?
http://www.dynasupport.com/faq/metal-forming/do-i-have-to-consider-the-thickness-of-the-rigid
Article Even if I include the card of *CONTROL_ADAPTIVE in my input deck, the blank is not adapted. How can I fix this problem?
http://www.dynasupport.com/faq/metal-forming/even-if-i-include-the-card-of-control-adaptive-in
Article How can I evaluate material formability for a new material?
http://www.dynasupport.com/faq/metal-forming/how-can-i-evaluate-material-formability-for-a-new
Article How can I specify friction coefficient in the contact interface?
http://www.dynasupport.com/faq/metal-forming/how-can-i-specify-friction-coefficient-in-the
Article How can you add constraints for a springback analysis?
http://www.dynasupport.com/faq/metal-forming/how-can-you-add-constraints-for-a-springback
Article How can you evaluate the material formability under complexity deformation condition or multiple steps forming?
http://www.dynasupport.com/faq/metal-forming/how-can-you-evaluate-the-material-formability
Article How do I choose the element type for the analysis of sheet metal stamping?
In LSDYNA, there are different elements available in the analysis of sheet metal stamping Would you please give me some advice on how to choose the proper element type?
http://www.dynasupport.com/faq/metal-forming/how-do-i-choose-the-element-type-for-the-analysis
Article How do I implement my own FLD in LSPOST?
http://www.dynasupport.com/faq/metal-forming/how-do-i-implement-my-own-fld-in-lspost
Article How do I specify the draw bead force?
http://www.dynasupport.com/faq/metal-forming/how-do-i-specify-the-draw-bead-force
Article How do I use define draw bead in stamping analysis?
http://www.dynasupport.com/faq/metal-forming/how-do-i-use-define-draw-bead-in-stamping-analysis
Article How do you perform a multiple step analysis?
http://www.dynasupport.com/faq/metal-forming/how-do-you-perform-a-multiple-step-analysis
Article How do you trim the blank after a forming analysis?
http://www.dynasupport.com/faq/metal-forming/how-do-you-trim-the-blank-after-a-forming-analysis
Article How do you use RIGID_BODY_STOPPER?
http://www.dynasupport.com/faq/metal-forming/how-do-you-use-rigid-body-stopper
Article Use the card of *CONSTRAINED_RIGID_BODY_STOPPERS You can constrain the displacement by specifying a negative value for LCMAX and LCMIN. How is seamless springback analysis done with LSDYNA?
http://www.dynasupport.com/faq/metal-forming/use-the-card-of-constrained-rigid-body
Article How is the FLD obtained in LSPOST? What is the limitation of using this FLD?
http://www.dynasupport.com/faq/metal-forming/how-is-the-fld-obtained-in-lspost-what-is-the
Article How many levels of adaptive mesh do I need in my calculation?
http://www.dynasupport.com/faq/metal-forming/how-many-levels-of-adaptive-mesh-do-i-need-in-my
Article How to do hydro forming analysis?
http://www.dynasupport.com/faq/metal-forming/how-to-do-hydro-forming-analysis
Article How to use non-smooth trimming?
http://www.dynasupport.com/faq/metal-forming/how-to-use-non-smooth-trimming
Article I found that the number of adapted elements was too large when I performed a multi-stage forming analysis using adaptivity. Is there a way to avoid this problem?
http://www.dynasupport.com/faq/metal-forming/i-found-that-the-number-of-adapted-elements-was
Article I generated a dynain file after forming analysis. Additionally, I used DYNAFORM to trim the mesh, and did springback prediction. However, I found that the predicted springback is too small to be true. What is the problem?
http://www.dynasupport.com/faq/metal-forming/i-generated-a-dynain-file-after-forming-analysis.
Article I had no problem in running a forming job, however, when I used adaptive method, the contact does work properly even from the beginning without adaptivity. What is the problem?
http://www.dynasupport.com/faq/metal-forming/i-had-no-problem-in-running-a-forming-job-however
Article I have no experience in springback prediction, and have no idea whether my prediction is reasonable. Do you have any idea how accurate the solution could be from LSDYNA?
http://www.dynasupport.com/faq/metal-forming/i-have-no-experience-in-springback-prediction-and
Article I just have one IGES file for the part, and I don’t want to offset the surface for the punch and die physically. Is it possible to offset the two surfaces internally inside LSDYNA3D? If yes, how do you offset these two surfaces?
http://www.dynasupport.com/faq/metal-forming/i-just-have-one-iges-file-for-the-part-and-i
Article I think spring back prediction by using implicit is not realistic. What is your opinion regarding the convergence issue?
Implicit spring back analysis is better if converged solution can be obtained. However, over the past two years, I have done over sixty forming simulations, and I only got two converged solutions for spring back simulation. So I think spring back prediction by using implicit is not realistic. What is your opinion regarding the convergence issue?
http://www.dynasupport.com/faq/metal-forming/i-think-spring-back-prediction-by-using-implicit
Article I tried to use LSPOST to compare the strain state with FLD. When I selected the element and clicked the plot button, nothing was plotted. What was the problem?
http://www.dynasupport.com/faq/metal-forming/i-tried-to-use-lspost-to-compare-the-strain-state
Article If a converged solution from springback prediction cannot be obtained after trying many different combinations of parameters, what else can I do?
http://www.dynasupport.com/faq/metal-forming/if-a-converged-solution-from-springback-prediction
Article If I didn’t find wrinkling and strain localization in from my simulation, can I say that my design is good?
http://www.dynasupport.com/faq/metal-forming/if-i-didn2019t-find-wrinkling-and-strain
Article If I use very coarse mesh for the pre-deformation (such as pre-bending, gravity loading etc), and then refine the mesh in the later forming analysis. Will it result in obvious numerical error for the final results?
http://www.dynasupport.com/faq/metal-forming/if-i-use-very-coarse-mesh-for-the-pre-deformation
Article If localized necking occurs what can I do to get rid of it?
http://www.dynasupport.com/faq/metal-forming/if-localized-necking-occurs-what-can-i-do-to-get
Article If wrinkling occurs, what can I do to get rid of it?
http://www.dynasupport.com/faq/metal-forming/if-wrinkling-occurs-what-can-i-do-to-get-rid-of-it
Article In implicit analysis of springback process, there are both linear and non-linear methods. Can you advise which one is better?
http://www.dynasupport.com/faq/metal-forming/in-implicit-analysis-of-springback-process-there
Article In implicit forming analysis, I found that the friction force was not properly applied, what could have been the problem?
http://www.dynasupport.com/faq/metal-forming/in-implicit-forming-analysis-i-found-that-the
Article In LS-DYNA, there are different material models and I’ve found it difficult to choose the proper material model. Would you please give me some suggestions in selecting the proper material model?
http://www.dynasupport.com/faq/metal-forming/in-ls-dyna-there-are-different-material-models-and
Article In my analysis of the sheet metal forming process, I frequently found that the calculation could not continue and it terminated unexpectedly. Is there a way to avoid this?
http://www.dynasupport.com/faq/metal-forming/in-my-analysis-of-the-sheet-metal-forming-process
Article In my simulation, some of the corner nodes can be put in the wrong place. Can you advise what the problem is?
http://www.dynasupport.com/faq/metal-forming/in-my-simulation-some-of-the-corner-nodes-can-be
Article In springback analysis I don't have enough memory or the analysis takes too much time. What can I do ?
In springback analysis I’ve found I have two problems: 1) When I use the implicit method I don’t have enough memory and can’t continue the calculation; and 2) At other times springback analysis takes too much time. Are there any methods available to solve these problem?
http://www.dynasupport.com/faq/metal-forming/in-springback-analysis-i-dont-have-enough-memory
Article In springback analysis, I found that my constraint hasn’t been taken into account during the simulation, what was the problem?
http://www.dynasupport.com/faq/metal-forming/in-springback-analysis-i-found-that-my-constraint
Article In springback analysis, I just changed the constrained nodes a little bit away from the original node. The convergence then became very different and the predicted result seems not to be reasonable. What can be the problem?
http://www.dynasupport.com/faq/metal-forming/in-springback-analysis-i-just-changed-the
Article In springback analysis, we had no problem when gravity effect is not considered. However, after gravity effect is included in the input deck, there were some strange error messages. What might be the cause?
http://www.dynasupport.com/faq/metal-forming/in-springback-analysis-we-had-no-problem-when
Article Is it possible to allow separation/gap between elements within one part?
http://www.dynasupport.com/faq/metal-forming/is-it-possible-to-allow-separation-gap-between
Article Is it possible to coarsen a uniformly refined mesh, as well as an adaptively generated mesh?
http://www.dynasupport.com/faq/metal-forming/is-it-possible-to-coarsen-a-uniformly-refined-mesh
Article Is it possible to do forming simulation by using both implicit and explicit method in the same run?
http://www.dynasupport.com/faq/metal-forming/is-it-possible-to-do-forming-simulation-by-using
Article Is the order relevant in which I do triming and coarsening of the mesh?
When I do springback analysis after trimming, I need to coarsen the mesh to decrease the memory requirement and increase the computation speed. We can trim the mesh first and then do coarsen the mesh; we also can coarsen the mesh first, and trim the mesh later. Is there any difference between the above two methods?
http://www.dynasupport.com/faq/metal-forming/is-the-order-relevant-in-which-i-do-triming-and
Article Is there a way to prevent distortion?
When the constraint contact is used, the mesh is distorted in the forming analysis. Is there a way to prevent this distortion?
http://www.dynasupport.com/faq/metal-forming/is-there-a-way-to-prevent-distortion
Article Is there a way to reduce the penetration problem?
When I do a forming analysis there is large penetration of the blank into the rigid tools. Is there a way to reduce the penetration problem?
http://www.dynasupport.com/faq/metal-forming/is-there-a-way-to-reduce-the-penetration-problem
Article Is there any limitation for LSDYNA3D to be applied to Metal-Forming analysis?
http://www.dynasupport.com/faq/metal-forming/is-there-any-limitation-for-lsdyna3d-to-be-applied
Article I’ve found that when I use several CPUs with the SMP code that only one CPU is working and the other CPUs are idle. What is the problem and how can it be corrected?
http://www.dynasupport.com/faq/metal-forming/i2019ve-found-that-when-i-use-several-cpus-with
Article No matter how I’ve tried, I can’t trim the elements with the IGES line data. Is there any alternative to do trimming?
http://www.dynasupport.com/faq/metal-forming/no-matter-how-i2019ve-tried-i-can2019t-trim-the
Article There are several linear solvers for implicit analysis. Can you tell me which one is the fastest and most accurate?
http://www.dynasupport.com/faq/metal-forming/there-are-several-linear-solvers-for-implicit
Article There are several non-linear solvers for implicit analysis - which one is better?
http://www.dynasupport.com/faq/metal-forming/there-are-several-non-linear-solvers-for-implicit
Article There is no load applied to the blank when I used *LOAD_MASK. What might be the problem?
When I used *LOAD_MASK for hydro-forming analysis, first I have no problem in applying the load, but the load is in the wrong direction. I used negative value for the load curve to reverse the load direction. However, there was no load applied to the blank anymore. What might be the problem?
http://www.dynasupport.com/faq/metal-forming/there-is-no-load-applied-to-the-blank-when-i-used
Article What are the differences between smooth and non-smooth trimming?
There are two methods in trimming, i.e. smooth and non-smooth trimming. In smooth trimming, the boundary element will be cut exactly along the trimming curve; while in non-smooth trimming, the boundary element can be either kept or removed from the model and it will not be cut in half. What is the advantage of each method?
http://www.dynasupport.com/faq/metal-forming/what-are-the-differences-between-smooth-and-non
Article What can I do if the direction of the pressure is not reasonable after the mesh had been refined adaptively?
When I used adaptive mesh in hydro forming simulation, there was no problem in the initial stage. However, I found that the direction of the pressure wasn’t reasonable after the mesh had been refined adaptively. What was the problem and how can it be fixed?
http://www.dynasupport.com/faq/metal-forming/what-can-i-do-if-the-direction-of-the-pressure-is
Article What can I do if the mesh for the last state was not written to the d3plot after restarting from d3dumpxx?
I performed springback analysis using the seamless method, but no converged solution was obtained. Then I wrote a small input deck and restarted the calculation from d3dumpxx. From the message file, the converged solution was obtained, but when I tried to use Taurus to display it, the mesh for the last stage was not written to the d3plot file. Is there a way to avoid this?
http://www.dynasupport.com/faq/metal-forming/what-can-i-do-if-the-mesh-for-the-last-state-was
Article What is FLD?
http://www.dynasupport.com/faq/metal-forming/what-is-fld
Article What is the commonly used contact type in stamping analysis?
In LSDYNA, there are many choices for contact. What is the commonly used contact type in stamping analysis?
http://www.dynasupport.com/faq/metal-forming/what-is-the-commonly-used-contact-type-in-stamping
Article What is the effect of R value (material anisotropic parameter) on FLD?
http://www.dynasupport.com/faq/metal-forming/what-is-the-effect-of-r-value-material-anisotropic
Article What is the effect of R-value on material formability?
http://www.dynasupport.com/faq/metal-forming/what-is-the-effect-of-r-value-on-material
Article What is the material formability?
http://www.dynasupport.com/faq/metal-forming/what-is-the-material-formability
Article What is the proper punch speed that could be used in stamping simulation?
http://www.dynasupport.com/faq/metal-forming/what-is-the-proper-punch-speed-that-could-be-used
Article What is the proper strategy to switch from implicit and explicit method or from explicit to implicit method?
http://www.dynasupport.com/faq/metal-forming/what-is-the-proper-strategy-to-switch-from
Article What is the use of defining a box for drawbead?
http://www.dynasupport.com/faq/metal-forming/what-is-the-use-of-defining-a-box-for-drawbead
Article What is the use of RIGID-BODY_STOPPER?
http://www.dynasupport.com/faq/metal-forming/what-is-the-use-of-rigid-body-stopper
Article What kind of velocity pattern is better for metal forming analysis?
http://www.dynasupport.com/faq/metal-forming/what-kind-of-velocity-pattern-is-better-for-metal
Article When I a used drawbead in the forming analysis, it was observed that some of the elements which moved over the bead line were distorted, and there is no obvious reason for this effect. What might be the problem?
http://www.dynasupport.com/faq/metal-forming/when-i-a-used-drawbead-in-the-forming-analysis-it
Article When I attempt to do a springback analysis, I sometimes have difficulty in obtaining a converged solution. What options are available to improve convergence of springback?
http://www.dynasupport.com/faq/metal-forming/when-i-attempt-to-do-a-springback-analysis-i
Article When I did dynamic relaxation analysis in gravity loading process, it took a long time to get a converged solution. Is there a way to make this analysis faster?
http://www.dynasupport.com/faq/metal-forming/when-i-did-dynamic-relaxation-analysis-in-gravity
Article When I did forming simulation, I found that a material failure was predicted earlier then expected, what might be the problem?
http://www.dynasupport.com/faq/metal-forming/when-i-did-forming-simulation-i-found-that-a
Article When I do springback analysis, the prediction is not satisfactory. I didn’t find any problem in the input deck. What should I check to improve the solution quality?
http://www.dynasupport.com/faq/metal-forming/when-i-do-springback-analysis-the-prediction-is
Article When I run forming simulation, I had such message as “Error: slaves nodes may cross the surface, please check your model, job continues.” I’ve checked my input deck and didn’t find any obvious mistake for the mesh. How can I fix this problem?
http://www.dynasupport.com/faq/metal-forming/when-i-run-forming-simulation-i-had-such-message
Article When I tried to trim the mesh after forming, the generated ‘dynain’ file contains the mesh without trimming, what is the problem and how can I fix it?
http://www.dynasupport.com/faq/metal-forming/when-i-tried-to-trim-the-mesh-after-forming-the
Article When I trim the blank using IGES file, there is a message such as “Entity type xxx form 0 not supported # lines = x”. What does it mean?
http://www.dynasupport.com/faq/metal-forming/when-i-trim-the-blank-using-iges-file-there-is-a
Article When I trimmed the mesh after forming, I only used one trim curve (in IGES format), but LSDYNA found 10 trimming curves. Accordingly, the result was not acceptable. What was the problem?
http://www.dynasupport.com/faq/metal-forming/when-i-trimmed-the-mesh-after-forming-i-only-used
Article When I use constrain method (SOFT=4 in the FORMING_ONE_WAY_xx card), the calculation terminates immediately, what is the problem?
http://www.dynasupport.com/faq/metal-forming/when-i-use-constrain-method-soft-4-in-the-forming
Article When I use FEA, I don’t know how big the mesh size should be. Would you please tell me what is the proper mesh size?
http://www.dynasupport.com/faq/metal-forming/when-i-use-fea-i-don2019t-know-how-big-the-mesh
Article When I use mesh adaptivity in my stamping simulation I don’t know how to define the proper adaptive frequency. Would you please give me some suggestions?
http://www.dynasupport.com/faq/metal-forming/when-i-use-mesh-adaptivity-in-my-stamping
Article When I use the implicit method to do springback analysis I cannot obtain a converged solution no matter what I’ve done. Do I have some other choices to obtain a converged solution for springback prediction?
http://www.dynasupport.com/faq/metal-forming/when-i-use-the-implicit-method-to-do-springback
Article When I used coarsening, I found that there is an error message:’ Something is wrong, sub: nextele’. What is the problem, and how can I avoid it?
http://www.dynasupport.com/faq/metal-forming/when-i-used-coarsening-i-found-that-there-is-an
Article When I used implicit method to do springback analysis, the iteration information was not output or displayed in the screen. I think this iteration information is important for me to monitor the convergence status. How can I display this information?
http://www.dynasupport.com/faq/metal-forming/when-i-used-implicit-method-to-do-springback
Article When I used switch method in my calculation, I used explicit method and then I changed to implicit method. In the later implicit calculation process, it was seen that the contact didn’t work properly. What was the problem, and how can I avoid this?
http://www.dynasupport.com/faq/metal-forming/when-i-used-switch-method-in-my-calculation-i-used
Article When I used the seamless method to do both forming and springback analysis, a converged solution wasn’t obtained. I don’t want to repeat the forming analysis. Is there a way I can repeat the springback analysis from the previous output files?
http://www.dynasupport.com/faq/metal-forming/when-i-used-the-seamless-method-to-do-both-forming
Article When the constraint contact is used, the calculation crashes during the forming analysis. What needs to be done to prevent this?
http://www.dynasupport.com/faq/metal-forming/when-the-constraint-contact-is-used-the
Article When we do springback analysis, we have two choices to do it, i.e. using implicit and explicit method (dynamic relaxation). What is the advantage of using the implicit method in springback analysis?
http://www.dynasupport.com/faq/metal-forming/when-we-do-springback-analysis-we-have-two-choices
Article Why does the restart of the springback analysis not work?
I attempted to restart the springback analysis from the d3dump01. The springback analysis was not performed even though the “message” file shows that the analysis terminated normally. What causes this problem and how can it be fixed?
http://www.dynasupport.com/faq/metal-forming/why-does-the-restart-of-the-springback-analysis
Article Why dynamic relaxation doesn’t seem to work at times?
http://www.dynasupport.com/faq/metal-forming/why-dynamic-relaxation-doesn2019t-seem-to-work-at
Article Will the mesh coarsening affect the accuracy of springback prediction?
http://www.dynasupport.com/faq/metal-forming/will-the-mesh-coarsening-affect-the-accuracy-of