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Rahul Ponginan

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Everything posted by Rahul Ponginan

  1. The equation of motion for a static analysis is as below: [K] {X} = {F} ------------------------------------------ (1) [K] --> Global Stiffness Matrix {X} --> Unknown Displacement {F} ---> External Force Applied. For the body to be in static equilibrium, the net force acting at every node must be zero. Therefore, the basic statement of static equilibrium is that the internal forces, I, and the external forces, F, must balance each other: [K] {X} is nothing but internal force 'I' Equation (1) now becomes, ==> I = F or I - F = 0 -----------------------------------(2) In Dynamic Analysis, the imbalance between the external and internal forces results in an acceleration: F - I = M a. F --> External Forces I ---> Internal Force M*a --> Inertial Forces (mass times acceleration) In linear static analysis the stiffness matrix is constant and shall not change/update throughout the analysis. There are many check need to be performed once you have linear static results for well conditioned problems. The equation (1) is decomposed one time to find the unknown displacement. [K] {X} ={F} After decomposition, a singularity may lead to an incorrect solution. In static analysis to obtain {X} (displacements). Using these displacements, One can calculate a “residual” loading vector as follows: [K] {X} -{F} =δ F This residual vector should theoretically be null (equation 2) but may not be null due to numeric roundoff. In Nonlinear static analysis, The stiffness matrix changes in each and every iteration since the stiffness matrix is dependent on the external load. The external load in Nonlinear static analysis is applied in increments and time here has no physical meaning. Time is just a convenient way to apply full load in nonlinear static analysis. In Optistruct the incremental load is controlled by 'NINC' field in the NLPARM card for NLSTAT load steps, this is a fixed load increment method. If you add the PARAM,EXPERTNL,YES to the deck, the time increment method becomes automatic in which case, the increment (load) is increased or cut back based on the convergence rate. NLGEOM loadstep has automatic time step by default. In NLGEOM loadstep the RAMP load curve can be defined using TABLED1 card and then refer this in NLOAD1 card. In nonlinear static analysis, OptiStruct uses the Newton-Raphson method to obtain solutions for nonlinear problems to maintain the residuals close to zero (equation 2) In a nonlinear analysis the solution usually cannot be calculated by solving a single system of equations, as would be done in a linear problem. Instead, the solution is found by applying the specified loads gradually and incrementally working toward the final solution. Therefore, OptiStruct breaks the simulation into a number of load increments (NINC) and finds the approximate equilibrium configuration at the end of each load increment. It is important that you clearly understand the difference between an analysis step (NLSTAT / NLGEOM), a load increment (NINC of NLPARM card), and an iteration (MAXITER of NLPARM card) The load history for a simulation consists of one or more steps. Within a step you will have many no of increments (NINC), within increment there can be many no. of iteration (MAXITER). OptiStruct checks the equilibrium equation ( equation 2) for each and every iteration. If the solution from an iteration is not converged, OptiStruct performs another iteration to try to bring the internal and external forces into balance. An increment is part of a step. An iteration is an attempt at finding an equilibrium solution in an increment when solving with an implicit method. If the model is not in equilibrium at the end of the iteration, OptiStruct tries another iteration. With every iteration the solution OptiStruct obtains should be closer to equilibrium; sometimes OptiStruct may need many iterations to obtain an equilibrium solution. When an equilibrium solution has been obtained, the increment is complete.
  2. You can fix this by closing all HW Applications and then searching/deleting the following folders: C:\ProgramData\x-formation %USERPROFILE%\AppData\Local\VirtualStore\ProgramData\x-formation\ss.<userID>.lock (if present) %USERPROFILE%\AppData\Local\x-formation\ %USERPROFILE%AppData\Local\Temp\x-formation C:\Windows\Temp\x-formation Once these folders are deleted, re-invoke the product. You should see it open immediately.
  3. Anomalies with the browsers, the user interface layout (tab locations, command window, panel location, toolbars,) keyboard preferences, import/export settings etc certain malfunctions with errors and crashes can generally be resolved by deleting the settings files. The following problems in HyperMesh have been successfully fixed by deleting the settings files. Entities missing Radio buttons missing in panel area Buttons missing in panel area Toolbar icons missing Utility menu is blank, browser has icons missing Status bar is missing Errors Can’t set hm framework minibar Segmentation error when user starts hm Fatal menu system error hmmenu.set has one or more fatal errors Menu system corrupted : menu itemgroup : get pointer “Only a single create/edit window supported at a time, do you want to close current window before proceeding” “Node command is out of sequence" while importing .fem file "Nodes already exist in the model" while converting Trias to tetras selection Unable to select lines and points from the graphics area, Unable to select elements, Entities do not change colour on being selected While selecting a node adjacent node gets selected. Unable to choose coincident nodes in the model. When user tries to choose one of the nodes at a particular location it does not show the option of picking one of the two or more nodes. crashes HyperMesh 11.0 crashes when he tries to translate a component operations The mesh is not seeded all along the edges of a model and not taking the element size specified When user tries to organize elements using organize option, elements are not moved and tool hangs graphics Panel area is resized User is not able to get White background JPEG if the Check box is marked for Blank background under options panel. While using automesh option, if user does a reject/abort, then all masked elements will be unmasked. i.e. If User masks some of the elements of the same and locally remeshes remaining elements with F12 and aborts the operation then masked elements will appear on the screen without doing unmask elements. Components are not being displayed in the graphics area, though they are active in the model browser and are not masked. Masked Temporary Nodes appear while selecting by window. Find attached elements will select all the elements including those in undisplayed components. The colour of the component does not match between that in the model browser and the graphics area. Creates a material and tries to update a card image but, it goes blank without displaying any options
  4. Check out the Altair University Facebook Page
  5. Search the Support forum - The support forum is an extensive database of queries from HyperWorks - FEA users worldwide, it is likely that your question has been asked and answered before, use the search option in the top right hand corner to search for your question. Search Help documentation - The full HyperWorks HTML documentation (part of your installation) provides a thorough, searchable resource to find detailed information about HyperWorks, including an extensive set of tutorials HyperWorks offers comprehensive documentation in the online help.The Help can be accessed through the menu bar or the use of the “h” , keyboard (help documentation is “intelligent”, opening in the section representing the panel that the user is actively in) Help also contains detailed tutorials on many advanced HyperMesh functions. Search and go through the Free E-Books - Design of Experiments with HyperStudy – A Study Guide Practical Aspects of Finite Element Simulation (A Study Guide) Practical Aspects of Structural Optimization (A Study Guide) Practical Aspects of Multi-Body Simulation with HyperWorks Crash Analysis With RADIOSS – A Study Guide 有限元仿真实践原理 Search and explore the Learning Library - An extensive collection of interactive training videos (with audio) covering the most essentials about interacting with the graphical user interface, basics of geometry cleanup, introduction in 2D meshing, analysis, debugging, topology optimization, and postprocessing (visit the Learning Library for more information) Search and explore Tips and Tricks
  6. Learn more about this from the FEA eBook http://www.altairuniversity.com/free-ebooks-2/free-ebook-practical-aspects-of-finite-element-simulation-a-study-guide/
  7. Please Use the Learning Library for Up To Date HyperWorks Learning Material
  8. Introducing HyperWorks 2017 A Platform for Innovation™ HyperWorks 2017 introduces several new products and hundreds of new features. Discover what’s new in each product included in the HyperWorks suite. Watch the overview videos to learn more about the latest release from our thought leaders at http://www.altairhyperworks.com/hw2017/
  9. Dynamic loads wrt to time are not supported in current Inspire versions, one can use Inspire Motion in the current versions (2017.3) to apply springs for an MBS analysis
  10. We see that you have ordered the Altair student edition from the Altair store and this was delivered to you, The software requires a license file to function, please login to your Altair Store account to download the license file. You should find the license file and the software in the Student Edition Downloads section,
  11. you need higher loads, a load on 150 N on a 150 kg steel block will not produce much effect...
  12. There is no non design space in your model, you need to apply the loads only on non design spaces as shown here
  13. The design space (cuboid in the center) appears to be missing from the analysis, the loads and supports are not applied on a connected solid entity,
  14. we have sent alternative links to the books by mail to you, Please check your junk / spam folders or enter a different email ID for the eBooks and try,
  15. Please add more constraints as it appears the model is not fully supported,
  16. Looks like the vectors have different lengths, you may need to adjust the input data so that your curves c2 and c4 have the same length
  17. altair client center login is replaced by connect as the source for downloads, executables and documentation.
  18. Can you please try with a different browser and choose to proceed (for eg you can use advanced > proceed in chrome)
  19. TechPassion presents VMAP (click here) VMAP is a comprehensive software tool for vibration testing on real-world engineering systems that seamlessly connects virtual simulation and physical testing. Vibration Measurement and Analysis Package (VMAP) represents the convergence of virtual prototyping and prototype testing. There are several parameters that cannot be modeled accurately in existing virtual prototyping tools and are dependent on experimental methods. VMAP bridges this gap between virtual prototyping and experimentation in product design cycle especially in the development of automotive, aerospace and energy systems. The system significantly improves productivity of product design teams by not only cutting costs and development time but also intangibles associated with inaccuracies in design. VMAP is a versatile software platform powered by accurate and efficient algorithms, friendly user-interfaces, rich and fast graphics and supports industry-standard file formats.
  20. New Feature in HW 2017 – Collision Detection Tool
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