Reg - Analysis of an elastomer behaviour
 

Dear All,

I set with a case that to analyse the elastomer behaviour. In our case a rubber seal need to be coupled between two mating parts. When these two mating parts mate, the groove for the seal will be obtained and thereby compressing the seal to deform for a certain extent.

In these mating part, one will be a fixed wall to the seal, and the other is going to be make the compression against the fixed wall.
(attached the geometry as "sealgeom.jpg")

I am working with ANSYS9.0 version. I started the pre processing considering the below steps:

· Creating Element type HYPER84 employing Mooney function, key opting with plane strain.
· Assigning Material Property NUXY – 0.49
· Creating Element Type COMBIN14 key opting linear solution, 1D longitudinal UX DOF
(Not assigned the real constants Spring Constant, Damping Coefficients Cv1& Cv2)
· Tabulating the Mooney Constants using TBDATA, as C1 = 1.252, C2 = 0.313 & d = 2/k = 1.2e-3
· Creating key points, lines, fillets, circles using those key points.
· Creating areas using those lines
· Meshing the line dedicated for Spring(COMBIN14) and area dedicated as O ring (HYPER84)
· Contact pair definition using Contact Wizard. Two pairs as Rigid-flexible & flexible – flexible pairs were created.
Thereby four element types comprises of two basic element types TARGE169 & CONTA172 were assigned to the pairs. (No Real constants were defined)
· Constraining the degrees of freedom for the fixed wall (bottom line) DOF,ALL, ALL
· Constraining the free end Ith node of spring – COMBIN14 - DOF, ALL, ALL
· Constraining the moving wall as (DOF, UX, ALL) / (DOF, UZ, ALL).
· Applying Deflection constraint as DOF,UY, -2.0
· NLGEOM, ON
· Run the solver.
· Returns without solving with few errors and warnings.
I am not sure the procedure or the theory am following for analysing a rubber based elastomer behaviour to find out its deformation, the shear stress induced, and contact stress distributions.

Could anybody advice me regarding the case and for the following queries:

would HYPER84 element type best for analysing the case and mooney values given will be appropriate?

Defining the CONTA172 & TARGE169 for the contact pair elements for two type of pairs, one is for rigid- flexible and flexible, flexible.

A weak stiffenss spring added to the case using COMBI14, and how to define in pre process.

Defining the real constants for the elements.

am facing the issue seriously in defining the pre process and the theory considering for the analysis.

Am kindly seeking for the suggestions and advices.

(attached herewith the CUI procedure "process.docx", error file "error.log" and the case file "oring.dbb")

Thank you in advance,

V.Hari Krishnan

adding another pic of the geometry
 

I have added few pictures for the same case.