50g的教程ansys學習專題contact

1、9. Bonded Contact00129012 Dec 19999-29. Bonded ContactContact between two objects is one of the most frequently encountered phenomena in engineering analysis.It is also one of the most difficult nonlinearities to handle because the stiffness can suddenly disappear or reappear depending on whether th

2、e objects are out of contact or in contact.A rubber seal invarious stages ofcontact as it is compressed by a rigid surface 00129012 Dec 19999-3.Bonded ContactMost contact analyses require advanced analytical techniques that are beyond the scope of this training course.However, one class of contact a

3、nalysis, known as assembly contact, can often be performed without knowledge of advanced techniques.Assembly contact uses the bonded option of ANSYS contact elements and is also called bonded contact.In this chapter, we will briefly describe how to set up and solve a bonded contact analysis:A. Defin

4、itionsB. Typical ProcedureC. Workshop00129012 Dec 19999-4Bonded ContactA. DefinitionsBonded Contact is a special case of contact analysis where the two contacting surfaces are assumed to be glued together throughout the analysis.The two contacting surfaces form a contact pair.One of the surfaces is

5、designated as the target surfaceAnd the other surface is called the contact surfaceContact surfaceTarget surface (inner surface of cylinder)00129012 Dec 19999-5Bonded Contact.DefinitionsAdvantages of bonded contact:Faster solutions since there are no contact convergence issues. Convenient for a quic

6、k analysis of assemblies, for example.Small-deflection cases can be run as linear analyses with one substep and one equilibrium iteration.Also allows large-deflection (nonlinear) analyses. (Coupling and constraint equations are not mended for nonlinear analyses.)00129012 Dec 19999-6Bonded ContactB.

7、Typical ProcedureSeven main steps:1.Create or import the geometry.2.Mesh all of the contacting bodies. (Required for step 3.)3.Create the contact pair.4.Specify the analysis type and solution controls.5.Apply loads and boundary conditions.6.Save the database.7.Solve and review results.We will expand

8、 on steps 3 and 4 next.00129012 Dec 19999-7Bonded ContactTypical ProcedureCreating the contact pairOnce the contacting bodies have been meshed, the next step is to create the contact pair, which consists of target surface elements and contact surface elements.The contact wizard provides an easy way

9、to do this.Preprocessor Create Contact Pair Contact Wizard.00129012 Dec 19999-8Bonded ContactTypical ProcedureFirst pick the target surface(s) on one part.00129012 Dec 19999-9Bonded ContactTypical ProcedureThen pick the contact surface(s) on the other part.00129012 Dec 19999-10Bonded ContactTypical

10、ProcedureThen establish contact settings. Many settings are available, but the common ones for bonded contact are:Coefficient of friction = 0Then under Optional Settings Contact Options tab:Initial penetration = Exclude everythingContact surface behavior = Bonded (always)00129012 Dec 19999-11Bonded

11、ContactTypical ProcedureFinally, generate the contact pair.ANSYS will create the contact and target elements, and identify the contact pair with a real constant set number.The contact pair is plotted with their element normals, which should be pointing to each other. (If not, you can flip them using

12、 Preprocessor Create Contact Pair View Pair.)00129012 Dec 19999-12Bonded ContactTypical ProcedureAnalysis type and solution controlsBoth static and modal analyses can be performed.Typical solution control settings for static analysis:Solution Soln ControlSmall displacement static.One substep nsubst,

13、1, which is the default.One equilibrium iteration neqit,1. This will cause a warning to be issued, but it is generally ok for bonded contact.00129012 Dec 19999-13Bonded ContactTypical ProcedureDemo:Resume contact.db (contains two bodies made of aluminum, meshed with PLANE82 elements)Bring up contact

14、 wizard and create contact pair using:target surfaces on bottom partcontact surfaces on top partMU = 0initial penetration = exclude everythingcontact behavior = bonded (always)Enter Solution and issue the following commands (in order):solc,offneqit,1SolvePlot SEQV, then animate it. Also show UX and UY contours to demon