Displacement-Controlled Indentation of Rubber Membrane--Reaction Forces too Low
Displacement-Controlled Indentation of Rubber Membrane--Reaction Forces too Low
(OP)
Hello,
I am trying to model the deflection of a rubber "membrane". The "membrane" is 250 mm in diameter and 0.5 mm in thickness; it is meshed with C3D6H elements and is modeled as an incompressible, neo-Hookean material with C10 = 0.17 MPa. The material is deformed 127 mm via displacement-controlled loading by a rigid body indentor with a radius of 50 mm. Standard "Hard Contact" with a friction coefficient of 0 describe the contact between the two surfaces. The model converges with the desired displacement, but the reaction forces are significantly lower than expected.
If there is any insight into what I may be doing wrong or leaving out, it would be greatly appreciated!
Thank you!
I am trying to model the deflection of a rubber "membrane". The "membrane" is 250 mm in diameter and 0.5 mm in thickness; it is meshed with C3D6H elements and is modeled as an incompressible, neo-Hookean material with C10 = 0.17 MPa. The material is deformed 127 mm via displacement-controlled loading by a rigid body indentor with a radius of 50 mm. Standard "Hard Contact" with a friction coefficient of 0 describe the contact between the two surfaces. The model converges with the desired displacement, but the reaction forces are significantly lower than expected.
If there is any insight into what I may be doing wrong or leaving out, it would be greatly appreciated!
Thank you!





RE: Displacement-Controlled Indentation of Rubber Membrane--Reaction Forces too Low
RE: Displacement-Controlled Indentation of Rubber Membrane--Reaction Forces too Low
RE: Displacement-Controlled Indentation of Rubber Membrane--Reaction Forces too Low
I have included my input file below. As a reference, at 50 mm displacement, the reaction force should be about 25 N; 100 mm displacement, 130 N reaction force; 127 mm, 200 N reaction force.
Thank you again!!
RE: Displacement-Controlled Indentation of Rubber Membrane--Reaction Forces too Low
Rob Stupplebeen
www.OptimalDevice.com
RE: Displacement-Controlled Indentation of Rubber Membrane--Reaction Forces too Low
Do you know of any other codes that let you carry out material parameter identification by driving Abaqus?
Are you new to this forum? If so, please read these FAQ:
http://www.eng-tips.com/faqs.cfm?fid=376
http://www.eng-tips.com/faqs.cfm?fid=1083
RE: Displacement-Controlled Indentation of Rubber Membrane--Reaction Forces too Low
Thank you again!
RE: Displacement-Controlled Indentation of Rubber Membrane--Reaction Forces too Low
Rob Stupplebeen
www.OptimalDevice.com
RE: Displacement-Controlled Indentation of Rubber Membrane--Reaction Forces too Low
My thought is that the discrepancy is related to either the interaction or mesh; however, I've checked each setting one-by-one and can't seem to resolve the issue. Are there specific settings that can alter the accuracy of the model?
RE: Displacement-Controlled Indentation of Rubber Membrane--Reaction Forces too Low
EMJohnsen, I do not currently have Abaqus but will soon. If you post your problem or a scrubbed version someone usually steps up to help. It usually turns out to be a minor slip-up like referencing the wrong material in a property or something else unpredictable.
I hope this helps.
Rob Stupplebeen
www.OptimalDevice.com
RE: Displacement-Controlled Indentation of Rubber Membrane--Reaction Forces too Low
I am modeling an indentation of an incompressible, hyperelastic material. The following are the specifications used:
Membrane diameter = 5 um
Indentor diameter = 0.5 um
Membrane thickness = 0.005 um
C10 = 2.7e-9 N/(um^2)
The material is to be indented 2500 nm.
The following plot are the results obtained via CGMD: http://files.engineering.com/getfile.aspx?folder=0... As you can see, my results do not match, and I just can't seem to find the issue. If you could please help it would be GREATLY appreciated!