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thomas100

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About thomas100

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  1. Hi Mario, Is it possible to change the background color from grey to while (same color as graph area) outside the graph area? Thanks.
  2. Hi, I have imported some data (csv file) into HG to generate the trend line (in the attachment), but I just can not smooth the sharp corner (dash line) like the excel do automatically. I am wondering is there any way I can do it (not using the filter)? Many thanks.
  3. Hi, I want to do a crash simulation on a tube at the speed 1mm/s (static). Is lsdyna capable to do it? If yes, how should I set up the time step? mesh size: 3mm termination time: 600000ms Many thanks.
  4. Hi Mario, If I go to the manual way, how can I apply 10H filter? Thanks.
  5. Hi Mario, Thanks for your tips. Now I can see *filter, *misc etc. menu as soon as I open the HV without registering. Is this normal? I have a look at filter menu, it looks like there is no predefined 10Hz filter. What should I do to pick up the 10Hz filter? Many thanks.
  6. Hi Mario, After adding the line "{mvp_toolbar_dir = "<adapt path>/MVP_Toolbar";include(mvp_toolbar_dir + "/preferences_macro.mvw")}" at the end of the preference file, i got a error message "could not preprocess the file" as soon as I open the hypergraph. Also in the installation guide saying "Load via the menu "Set Preference File ..."", but there is no option "set preference file" in the menu. Please help.
  7. Hi Mario, Thanks for your tips and it is really helpful. I still have three questions about CFL criterion: Q1: As far as I understand through the reading, the time step applied to the simulation must be less than that calculated from the CFL criterion. But from the HV, it gives the minimum time step. Does it mean I need to apply a time step bigger than it? If so, it conflicts with CFL criterion. Q2: I have also done a simulation with a reasonable time step 0.9*|-0.05| (TFFSAC*DT2MS in the control_timestep keyword) for a termination of 1000. (unit in ms) The simulation went well. This also conflict with the minimum time step given by HV. Q3: I have tried a very big time step 500 (termination time is 100000, unit in ms), as soon as I tried to run the simulation, the solver just simply crashed and told me to close the program. I have tried three times, but every time is the same. Is there a maximum accepted value by the solver? If so, how much is it? If not, why it didn't go through the simulation like in Q2 with a bigger time step? Thanks a lot.
  8. I just realize if the formula t=L/(sqrt(E/p*(1-v^2))) is used to calculate the critical time step, since the density of metal is always with e-6, when it gets out of the square root, e-3 is maintained and the time step is always around 0.001ms which is too small. Please help.
  9. Hi, I recently mesh an aluminium tube with 3mm square shell element and applied a time step ("control_timestep") with parameter of TSSFAC 0.9 and DT2MS -0.05. So the calculated time step is 0.045ms. (unit system: Gpa, mm, ms, kg) As soon as I assigned crashing velocity as 150mm/s, the simulation went well and yet a reasonable result. Q1: according to the CFL condition, the time step can be calculated by the formula t=L/(sqrt(E/p*(1-v^2))). But if I use this formula, the time step is 0.55e-3ms which much much smaller than 0.045ms. Since the calculation gives the minimum time step, how is it possible to give me the correct simulation result by using a bigger one? Q2: when I assigned another speed 0.33mm/s, I just got a straight line (see attachment) over the force-time curve. What should I put in the control_timestep card? Please help. Many thanks.
  10. Hi Mario, If I don't use the MVP tool for filter (actually it looks like bit hard for me to get started), how should I apply a 10Hz filter to the curve? I saw there is one option called SAE General which I think is a self defined tool to apply any filter class. For the 10Hz class, what should I put in the three displayed fields: curve(time=second), filter class, time conv. ? Many thanks.
  11. I just got another issue. when I tried to apply the SAE60 filter to the force-displacement and force-time curves, I got two same warning message: referenced page is not valid. I didn't change the file location and haven't made any modification to the files. I can't figure out the meaning of this message??? Many thanks.
  12. forgot something in the precious post. There is only options like 60Hz, 120Hz in the menu. And if I can apply a 10Hz filter, how should I do it?
  13. Hi Mario, Thank you for your reply. I just have another question. I have successfully generate the force-displacement curve by following your instructions. Is it possible to apply a SAE 10Hz filter to the force-displacement curve I just generated since I can see there is a lot of noise within the curve. Many thanks.
  14. Hi, Recently I have done a crashing simulation, but I can get force-time curve from key word RCFORCE and the displacement information from key word NODEOUT. But I just cannot combine them into force-displacement curve. Is there any way that I can do it? Many thanks.
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