Learning Forum

[warrensu]

I am currently modeling a PCB undergoing reflow in order to look at its warpage. Ideally, I like to run my simulation three times (Heat -> Cool down -> Reheat) to represent the thermal cycling condition that occurs in reality. In the first run, the simulation would start with an undeformed model. Then, in the second run, I would like Ansys to start with a model that contains the deformation distribution from the first run.

How can I change the model after my first run and before my second run is my main question here.

So here's my thought on how to approach this:

After the first run, deactivate all of the elements for the PCB and reactivate with no strain in order to remove the stress components of the elements. Using this technique, the FEA model of PCB in the second run will only have the deformation distribution. But how can I implement this? Through some kind of commands?

Any suggestion on how to implement is greatly appreciated! Thanks!

[1shan]

You could do 2 linked analysis, where the second one uses the deformed model of the first. To do this simply connect the solution cell of the first to the model cell of the second, something like https://www.youtube.com/watch?v=pleyVI4AZj0.

Regards Ishan.

[warrensu]

Thanks for the suggestion! This method works great for analysis with only a few steps. But, ideally, I hope to simulate 10~20 thermal cycles or more...and creating a block for every step would be almost impossible.

[1shan]

You might wanna check the UPGEOM command. I also think the procedure you mentioned can work! I tried it for a static structural simulation. You will have to deactivate any loads that act on the model while the elements are dead.
Regards Ishan.

[warrensu]

I tried implement the method you suggested by dragging the solution into a new block, but I encounter this error below. My model is a 2D shell and it contains imported trace.

System.InvalidOperationException: Assembly Failed. Error assembling pmdb and acmo files : Combined scale factor is out of the supported range [1e-3, 1e+3]
at Ansys.Addins.Infrastructure.Remoting.RemotingApiHelper.FatalApiMethodInvalidOperationException(String message, RemotingApiMethod callback)
at Ansys.Simulation.Core.ISimulationHelperWrapper.Assemble(ModelAssemblyFileOptions& modelAssemblyFileOptions, AssemblyOptions& assemblyOptions)
at Ansys.Simulation.Core.Commands.AddinModelAssembler.AssembleGeometryAndMesh(IFullContext context, ModelAssemblyFileOptions& modelAssemblyFileOptions, AssemblyOptions& assemblyOptions)
--- Ans.ModelConverter.RemoteLib.Exceptions.ModelTransferFailedException: Assembly Failed. Error assembling pmdb and acmo files : Combined scale factor is out of the supported range [1e-3, 1e+3]
at Ansys.Simulation.Core.Commands.AddinModelAssembler.AssembleGeometryAndMesh(IFullContext context, ModelAssemblyFileOptions& modelAssemblyFileOptions, AssemblyOptions& assemblyOptions)
at Ansys.Simulation.Core.Commands.AddinModelAssembler.Assemble(IFullContext context, ModelAssemblyFileOptions modelAssemblyFileOptions, IAssemblyOptionsProvider assemblyOptionProvider)
at Ans.ModelConverter.RemoteLib.AddinWorkflow.AssemblyBase.Assemble(IFullContext context)
at Ansys.Simulation.Core.Commands.AddinModelAssembler.Assemble(IFullContext context)
at Ansys.Simulation.Core.Commands.RefreshModel.ProcessAssemblyFiles(IFullContext context, Dictionary`2 modelConversionFilesMap, Dictionary`2 modelAssemblyFilesMap)
at Ansys.Simulation.Core.Commands.RefreshModel.ExecuteCommand(IFullContext context)
--- Ans.ModelConverter.RemoteLib.Exceptions.ModelTransferFailedException: Assembly Failed. Error assembling pmdb and acmo files : Combined scale factor is out of the supported range [1e-3, 1e+3]
at Ansys.Simulation.Core.Commands.RefreshModel.ExecuteCommand(IFullContext context)
at Ansys.Addins.Infrastructure.CommandUtilities.CommandHelper.Execute(IFullContext context)
at Ansys.Core.Commands.Concurrency.CommandWorkUnit.executeInContext(CommandContext subContext, IExecutionEngineCallback tracer)
at Ansys.Core.Commands.Concurrency.BaseWorkUnit.doExecute(IExecutionEngineCallback executionEngine, CommandContext subContext)
at Ansys.Core.Commands.Concurrency.BaseWorkUnit.Execute(IExecutionEngineCallback executionEngine, Boolean dontCatchExceptions)
--- Ansys.Core.Commands.CommandFailedException: Assembly Failed. Error assembling pmdb and acmo files : Combined scale factor is out of the supported range [1e-3, 1e+3]
CommandName: Mechanical.RefreshModel(Container="Model 7", RemainingContainers=[])
at Ansys.Core.Commands.CommandAsyncResult.RethrowFailureException(Exception e)
at Ansys.Core.Commands.CommandAsyncResult.Wait(Int32 milliSecondsTimeout, Boolean exitContext)
at Ansys.ProjectSchematic.Commands.RefreshCommand.RefreshComponents(IFullContext context, IEnumerable`1 componentsToRefresh, Boolean refreshUnfulfilled)
at Ansys.Core.Commands.Concurrency.CommandWorkUnit.executeInContext(CommandContext subContext, IExecutionEngineCallback tracer)
at Ansys.Core.Commands.Concurrency.BaseWorkUnit.doExecute(IExecutionEngineCallback executionEngine, CommandContext subContext)
at Ansys.Core.Commands.Concurrency.BaseWorkUnit.Execute(IExecutionEngineCallback executionEngine, Boolean dontCatchExceptions)
--- Ansys.Core.Commands.CommandFailedException: Assembly Failed. Error assembling pmdb and acmo files : Combined scale factor is out of the supported range [1e-3, 1e+3]
CommandName: RefreshComponent(Component="/Schematic/Component:Model 7")
at Ansys.Core.Commands.CommandAsyncResult.RethrowFailureException(Exception e)
at Ansys.Core.Commands.CommandAsyncResult.Wait(Int32 milliSecondsTimeout, Boolean exitContext)
at Ansys.ProjectSchematic.Commands.RefreshComponentCommand.InvokeAndWait(IProtectedContext context, DataReference Component)
at Ansys.UI.GuiOperationContext.Invoke(GuiOperationMetaData operationData)
at Ansys.UI.UIManager.InvokeOperationCore(String pseudoname, OperationDelegate callback, Boolean allowOSMessages, Boolean coreTransaction, Boolean deferredRefreshOnly)

[warrensu]

For the UPGEOM commands, do you mind listing out what exactly you typed alongside some brief explanations of what each one of them does? Thank you!

[warrensu]

As described above, I like to model a thermal cycling condition where my PCB will heat -> cooldown -> reheat again. In reality, deformation after three cycles will definitely be different from after just one cycle of heating and cooling. In ANSYS Static Structural, I added the following temperature points to my thermal condition.
However, the deformation after cooling down is the same as when it was heating up.
This led me to look into the ekill and ealive commands which supposedly should deactivate all the elements and reactivate them (reactivated elements should have zero strains) before proceeding to solve the next step. But, I still get the same values for deformation.
What else can I possibly attempt to reach the desired outcome I want to see? Thanks!

[alexandrecferreira]

Did you get any solution to the error:
"Combined scale factor is out of the supported range [1e-3, 1e+3]"

Currently, I'm trying to perform a post-buckling analysis, and I've come across the same kind of error.

Either way, I appreciate any suggestions! Thanks