Ansys Pinball Radius
Madison Rapelyea
The pinball region size (i.e., "pinball radius") defines the boundary between near field and far field open status. The code only calculates gap data for elements in near open stauts. Pinball will influence what amount of gap or penetration is allowed for bonded contact. (In other words, if your clearance < pinball radius, the two surfaces will be bonded together.) The pinball radius is also used in frictional contact to define near vs. far-field contact - if contact elements are in the near-field to the target elements, then more contact checking is performed. Since the default, automatically-calculated pinball radius value is based on the mesh density, having a finer mesh will result in a smaller pinball radius and this may cause problem.
Hi Ayeon Hwang,
Will you please explain the question in a little bit of detail? As I can see, the inner geometry is separated from the outer geometry in the first images. Are you expecting any radial contraction of the inner part of the geometry? Are you expecting the inner geometry to move opposite the movement in the attached image? It all depends on the boundary condition that you have applied.
Regards,
Sampat
Hi,
It all depends on the geometry and boundary condition that you have applied. Will you please upload a screenshot of the original geometry and boundary conditions that you have applied?
Regards,
Sampat
I made two solids in spaceclaim.
And I used the static structural function in workbench.
I don't know how to set a boundary condition here.
I've tried it on Fluent.
The two geometry have different properties.
I want the inner geometry to expand.
Hi Ayeon ,
Will you please check the connection that you have applied for? Please establish contact between the two parts. Are you seeing the result on a large scale? I would recommend you see the result on a true scale.
You can adjust the pinball radius to detect the contact between the inner and outer geometry. You will find the pinball radius option in the contact details. You can also check the status of the contact by using the contact tool.
Regards,
Sampat
I have already met the conditions.
But nothing has changed.
I changed it to Frictional, Frictionless, and no separate, but the result is the same.
Is there any other solution?
The inner geometry was defined as stent and the outer geometry as artery.
I want to see the effect of stent on the artery.
But my simulation result is that stent goes out of the artery.
The elasticity of stent was expected to inflate the artery.
How can I solve this?
Hi Ayeon,
Will you please tell me the issues in detail? Where is it available? Or you can post this in the separate forum question so that this forum thread would remain separate for your model-specific and problem-related contact and boundary condition.
Regards,
Sampat
Hi Ayeon,
We Ansys employees are not allowed to handle any external links or files; maybe someone outside of Ansys would help you with this file.Your model has converged with your loading and boundary conditions. The solver has automatically added a Weak spring to converge this model.What type of result do you obtain when you use frictional contact instead of no separation contact?
Regards,
Sampat
Physically move contact nodes tothe target in order to close a gap or reduce penetration. The initialadjustment is converted to structural displacement values (UX, UY,UZ) and stored in the Jobname.RCN file.
Physically move contact nodes tothe target in order to close a gap or reduce penetration, and alsomorph the underlying solid mesh. The initial adjustment of contactnodes and repositioning of solid element nodes due to mesh morphingare converted to structural displacement values (UX, UY, UZ) and storedin the Jobname.RCN file.
Automatically sets certain real constantsand key options to recommended values or settings in order to achievebetter convergence based on overall contact pair behaviors. This optionis not valid for general contact.
For pair-based contact, the range of real constantpair ID's for which Option will be performed.If RID2 is not specified, it defaults to RID1. If no value is specified, all contact pairs inthe selected set of elements are considered.
For generalcontact (InterType = GCN), RID1 and RID2 are sectionIDs associated with general contact surfaces instead of real constantIDs. If RINC = 0, the Option is performed between the two sections, RID1 and RID2. If RINC > 0, the Option is performed among allspecified sections (RID1 to RID2 with increment of RINC).
Control parameter for opening gap. Close the openinggap if the absolute value of the gap is smaller than the CGAP value. CGAP defaultsto 0.25*PINB (where PINB is the pinball radius) for bonded and no-separationcontact; otherwise it defaults to the value of real constant ICONT.
Control parameter for initial penetration. Close theinitial penetration if the absolute value of the penetration is smallerthan the CPEN value. CPEN defaults to 0.25*PINB (where PINB is the pinball radius) for anytype of interface behavior (either bonded or standard contact).
Control parameter for initial adjustment. Input apositive value to adjust the contact nodes towards the target surfacewith a constant interference distance equal to IOFF. Input a negative value to adjust the contact node towards the targetsurface with a uniform gap distance equal to the absolute value of IOFF.
The command CNCHECK,POST solves the initialcontact configuration in one substep. After issuing this command,you can postprocess the contact result items as you would for anyother converged load step; however, only the contact status, contactpenetration or gap, and contact pressure will have meaningful values.Other contact quantities (friction stress, sliding distance, chattering)will be available but are not useful.
If CNCHECK,POST is issued within the solutionprocessor, the SOLVE command that solves the firstload step of your analysis should appear in a different step, as shownin the following example:
CNCHECK,POST writes initial contact resultsto a file named Jobname.RCN. When postprocessingthe initial contact state, you need to explicitly read results fromthis file using the FILE and SET,FIRST commands in POST1 to properly read the corresponding contactdata. Otherwise, the results may be read improperly. The followingexample shows a valid command sequence for plotting the initial contactgap:
You can issue CNCHECK,ADJUST to physically move contact nodes to the target surface. Youcan also issue CNCHECK,MORPH to physically movecontact nodes to the target surface and then morph the underlyingmesh to improve the mesh quality. See Physically Moving Contact Nodes Towards the Target Surface in the Contact Technology Guide for more information.Similar to the POST option, if CNCHECK,ADJUST or CNCHECK,MORPH is issued within the solution processor,the SOLVE command that solves the first load stepof your analysis should appear in a different step:
After issuing the CNCHECK,ADJUST command, the initial adjustment is converted to structuraldisplacement values (UX, UY, UZ) and stored in a file named Jobname.RCN. Similarly, the CNCHECK,MORPH command converts the initial adjustment of contact nodes aswell as the morphing adjustment of solid element nodes to structuraldisplacement values (UX, UY, UZ) and stores them in the Jobname.RCN file. You can use this file to plot or listnodal adjustment vectors or create a contour plot of the adjustmentmagnitudes via the displacements. When postprocessing the nodal adjustmentvalues, you need to explicitly read results from this file using the FILE and SET,FIRST commands in POST1to properly read the corresponding contact data. Otherwise, the resultsmay be read improperly.
The command CNCHECK,RESET allows you to resetall but a few key options and real constants associated with the specifiedcontact pairs (RID1, RID2, RINC) to their default values. Thisoption is only valid for pair-based contact definitions.
The command CNCHECK,AUTO automatically changescertain default or undefined key options and real constants to optimizedsettings or values. The changes are based on overall contact pairbehaviors. In general, this command improves convergence for nonlinearcontact analysis. This option is only valid for pair-based contactdefinitions.
The tables below list typical KEYOPT and real constant settingsimplemented by CNCHECK,AUTO. The actual settingsimplemented for your specific model may vary from what is describedhere. You should always verify the modified settings by issuing CNCHECK,DETAIL to list current contact pair properties.
The arched body shown in Fig 1, is supposed to act as a mold for the flat pane. I don't want the mold to be deformed, I just want the loaded pane to follow it's geometry. Therefore, for the mold, I defined the Stiffness Behavior (Mechanical > Geometry > Definition) as Rigid.
When the mesh is generated, only the upper surface of the mold seems to be meshed (as in Fig).
I don't have a lot of experience in ANSYS, therefore if you have any suggestions on how to define Contact (or which type), can you please let me know? Moreover, the lower face of the pane is a continuous one; should this face be split in two, one of those to be the same width as mould?
Is the pane a surface body assigned the thickness of the pane? That is what you want, not a solid body. A surface body will be meshed with shell elements that are very good at computing bending. A solid body needs many elements through the thickness to give good results for bending problems.