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Search result for: Bergstrom-Boyce
| # | Post Title | Result Info | Date | User | Forum |
| Bergstrom Boyce Model in Abaqus explicit | 17 Relevance | 7 years ago | Kinsy2324 | Bergstrom-Boyce Model | |
| Hello to all, After the determination of the parameter of Bergstrom boyce, I will use their (*Hysteresis) in abaqus explicit. But the post treatment shown an error THIS KEYWORD IS NOT AVAILABLE IN Abaqus/Explicit. Please, how i can fend this problem!! what is the idea?? | |||||
| The Bergstrom-Boyce Model: Experiments & Predictions | 17 Relevance | 14 years ago | Jorgen | Finite Element Modeling | |
| [IMG] [/IMG] I have made available a pdf-file ([URL= that discusses representative experimental data for elastomeric materials and how the observed non-linear strain, strain-rate, and hysteretic behavior can be modeled using the Bergstrom-Boyce (BB) model. | |||||
| Bergstrom-Boyce Model Theory | 17 Relevance | 14 years ago | Jorgen | Bergstrom-Boyce Model | |
| This pdf-file is a draft working document that describes the foundation and implementation of the Bergstrom-Boyce model for predicting the behavior of rubber elastic materials. The final version of this document is published in J. Mech. Phys. Solids, Vol 46, pp. 931-954, 1998. Attachment:Bergstrom_Boyce_model1.pdf | |||||
| elastomers - strain dependent behaviour ABAQUS | 15 Relevance | 11 years ago | Jorgen | Elastomers | |
| Great Thesis Anders! The Bergstrom-Boyce (*Hysteresis) model captures qualitatively both the strain amplitude and the frequency response of elastomers. It does not, however, do a great job of qualitatively predicting the response for industrially relevant applications. The good news is that the Bergstrom-Boyce model can easily be extended to better capture the dynamic response. I have developed model that does this nicely - the Dynamic-Bergstrom-Boyce model. This model is commercially [URL= Send me an email if you are interested. -Jorgen | |||||
| MSC MARC Implementation of BB material model | 14 Relevance | 5 years ago | fanggd | Bergstrom-Boyce Model | |
| Hi, what i found out so far is the following: Arruda-Boyce-Constants for Network B: [B]MARC nkT[/B] is the same as [B]mu_B[/B] (initial shear modulus) found in the papers [URL= [B]MARC Chain Length[/B] is the same as sqrt(stretch_lock), where stretch_lock is the stretch where the chains begin to lock the stress strain behaviour. For the parameters of the evolution law just read the papers in the link above: Multiplier = hat{C}, Exponent = c, Stretch sensitivity = m. There is barely any documentation inside Marc regarding Arruda-Boyce and Bergstroem-Boyce and especially their implementations, just a sample data set: Multiplier: 1.75 Exponent: -1 Stretch Sens.: 4 Maybe you could post your experiences with this model, i would be really interested! Good luck and best regargs, Andreas EDIT: I have to correct the definition of the Multiplier - it is hat{C}/(sqrt(2)^m). Found it somewhere in the Docs of Mentat 2015. | |||||
| weakness of the Arruda-Boyce model in Abaqus? | 14 Relevance | 15 years ago | Jorgen | Constitutive Models | |
| ... model for glassy polymers. The 8-chain model is implemented in ABAQUS, but the Arruda-Boyce viscoplasticity model is not implemented in ABAQUS. Some years ago I developed a model with M.C. Boyce that is now implemented in ABAQUS. This model is often called the Bergstrom-Boyce (BB) model, and can be activated in ABAQUS using the *Hysteresis command. The BB model was developed for elastomer-like materials. The Hybrid model (HM) is a a new advanced model for thermoplastics that is not available in ABAQUS. I also recently developed a model for predict ... | |||||
| Accurate material model for Teflon | 13 Relevance | 7 years ago | kale496 | Thermoplastics | |
| [QUOTE=ravishankar,11427]I am trying to find material parameters for Teflon with simple tension data (multiple cyclic loading at different temperatures). From Mcalibration, the following models are available - Bergstrom Boyce, Bergstrom Boyce Mullins, Dual Network Fluoropolymer, Three Network Model, Hybrid Model. Out of all these, BBM seems to give the best fit of 0.89 (R2). However, DNF, which was specifically made for Teflon in Bergstrom and Hilbert paper gives a fit of only 0.72. TNM and BB give lesser than BBM (around 0.78). 1. So, how to decide which model is best ? 2. Also, is it possible by the user to adjust the values of parameters to improve the fitness or is it that whatever the optimization results are the best one could get (implying that material model itself is not accurate)? -Ravishankar[/QUOTE] Teflon is the brand name of a compound discovered by Roy J. Plunkett (1910-1994) of DuPont in 1938 and introduced as a commercial product in 1946. Teflon is polytetrafluoroethene (PTFE).Teflon is also used as the trade name for a polymer with similar properties, perfluoroalkoxy polymer resin (PFA). | |||||
| Accurate material model for Teflon | 13 Relevance | 7 years ago | Krisandersen | Thermoplastics | |
| I am trying to find material parameters for Teflon with simple tension data (multiple cyclic loading at different temperatures). From Mcalibration, the following models are available - Bergstrom Boyce, Bergstrom Boyce Mullins, Dual Network Fluoropolymer, Three Network Model, Hybrid Model. Out of all these, BBM seems to give the best fit of 0.89 (R2). However, DNF, which was specifically made for Teflon in Bergstrom and Hilbert paper gives a fit of only 0.72. TNM and BB give lesser than BBM (around 0.78). 1. So, how to decide which model is best ? 2. Also, is it possible by the user to adjust the values of parameters to improve the fitness or is it that whatever the optimization results are the best one could get (implying that material model itself is not accurate)? -Ravishankar | |||||
| Help ansys designations | 13 Relevance | 11 years ago | jrw5001 | Constitutive Models | |
| ... as: TB, BB, 1, , , ISO !Activate Bergstrom-Boyce ISO data table TBDATA, 1, 1.31 !Define material constant μ,A , TBDATA, 2, 9.0 !Define N0=(λ,Alock)2 TBDATA, 3, 4.45 !Define material constant μ,B TBDATA, 4, 9.0 !Define N1=(λ,Block)2 TBDATA, 5, 0.33 !Define material constant TBDATA, 6, -1 !Define material constant c TBDATA, 7, 5.21 !Define material constant m ! TB, BB, 1, , , PVOL !Activate Bergstrom-Boyce PVOL data table T ... | |||||
| Doubt about Elastomers | 13 Relevance | 12 years ago | ghazel | Constitutive Models | |
| ... the downloadable-documents related to the Bergstrom-Boyce Model in the Forum and it does look like the most enriched model for elastomers ... I have a few general questions:[/COLOR] [B] [COLOR=Red]1 )Are there any published literature which utilizes the Abaqus/LS-Dyna implementation of the Advanced Bergstrom-Boyce Model ? 2) Whats the acquisition process & price of Poly-UMOD Library? 3) Are there any Open-Access or Evaluation versions of the same?[/COLOR] [/B] Regards, Sban | |||||
| RE: Constitutive model of BERGSTROM-BOYCE MODEL | 13 Relevance | 12 months ago | zci89 | Constitutive Models | |
| Hello Frank @FrankMonkey , i am very interested in BB model. I kindly ask you to send me also the subroutine files. Please send them via zub.ciprian@yahoo.com Regards, Ciprian | |||||
| RE: Network B in Bergstrom-Boyce Model | 13 Relevance | 1 year ago | Jorgen | Bergstrom-Boyce Model | |
| Thanks for the images. I am starting to understand your question. You are right, the F tensor can be determined from the applied strain (well, at least the F_11). The way to determine the Fe tensor is from: That is, you need to first calculate the Fp tensor (from the flow rate equation), and then you can calculate the Fe tensor. -Jorgen | |||||
| RE: Network B in Bergstrom-Boyce Model | 13 Relevance | 1 year ago | kate_jelaine | Bergstrom-Boyce Model | |
| Hello Jorgen, Thank you for your response. In regards to the Fe tensor, I am having difficulty understanding where to take data from. In particular, I am utilizing the (2005) paper to try and replicate your stress-strain plots for PTFE at -53 C. While using the BB model, network B calls for the 8-chain model (same as network A) except now the Fe deformation matrix is being used. I am not exactly certain how to get this tensor. I am using the function Grabit in MATLAB to get data from the plots in order to try and replicate them via the BB model. When I attempt to model this data in MATLAB, my plot does not look as it should and I think the issue revolves around the deformation matrices. Hopefully that gives a little more specificity for the question. Attachment:PTFE Stress Strain.PNG Attachment:PTFE Relazation Time.PNG Attachment:BB plot.jpg Attached are the plots I am attempting to replicate. FIGURE 1: I am pulling data from the -53 C curve and using the true strain to form the F tensor. FIGURE 2: Pulling data from this curve to generate Fe matrix? FIGURE 3: My plots from MATLAB | |||||
| RE: Network B in Bergstrom-Boyce Model | 13 Relevance | 1 year ago | Jorgen | Bergstrom-Boyce Model | |
| Hello Kate - Welcome to the forum 😀 I am not sure I fully understand your question. If your goal is to calibrate (find) the BB model parameters that match some experimental data, then I would recommend you using the MCalibration software. It is very easy to use, and you can get a free trial license by clicking on the button on the front page of PolymerFEM.com If your goal is to create your own implementation of the BB model then I recommend that you read my Polymer Mechanics book, which contains (I think) a Python implementation of the BB model. If you have a specific question about the Fe tensor, then can you please provide a bit more details here? -Jorgen | |||||
| RE: Bergstrom Boyce Model and VUMAT subroutine | 13 Relevance | 1 year ago | Jorgen | Bergstrom-Boyce Model | |
| Can you check your input file? It should have worked. | |||||