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| # | Post Title | Result Info | Date | User | Forum |
| Bergstrom Boyce Model in Abaqus explicit | 16 Relevance | 9 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 | 16 Relevance | 15 years ago | Jorgen | Finite Element Modeling | |
| [IMG] [/IMG] I have made available a pdf-file ([URL= ]Bergstrom_Boyce_model1.pdf[/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 | 16 Relevance | 15 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. | |||||
| elastomers - strain dependent behaviour ABAQUS | 14 Relevance | 13 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= ]available[/URL]. Send me an email if you are interested. -Jo ... | |||||
| MSC MARC Implementation of BB material model | 12 Relevance | 7 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= ]here[/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? | 12 Relevance | 17 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 ... | |||||
| Can't use calibrated PolyUMod Bergstrom-Boyce for FE simulations | 12 Relevance | 7 months ago | abetosam | Bergstrom-Boyce Model | |
| Hi all, I was able to calibrate the BB model to my data. I have 3 curves at different strain rates all coming from uniaxial tension experiments. The model seems to fit the data great, but it always fails whenever I try to run the validation for FE simulation. I try changing the solver from default to Abaqus when doing that I can't even get it to run. Additionally, I exported the model as a script and imported it into Abaqus but whenever I run a job I get deformation on the material although the stresses are zero. Another thing that I checked is the units, I set my units to be micro newtons for force and micrometers squared for length which matches my experimental data where my stresses are in MPa. But for some reason, I get values of the order 10^-6 in my stresses. This only happens in the graph, if I edit the data it does come out to what I had input. What am I doing wrong here? I am new to all of this, and any help would be greatly appreciated. I've attached some pictures that might be helpful please let me know if any other details are necessary. | |||||
| RE: Constitutive model of BERGSTROM-BOYCE MODEL | 12 Relevance | 3 years 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 | 12 Relevance | 3 years 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 | 12 Relevance | 3 years 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. 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 | 12 Relevance | 3 years 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 | 12 Relevance | 3 years ago | Jorgen | Bergstrom-Boyce Model | |
| Can you check your input file? It should have worked. | |||||
| RE: Bergstrom Boyce Model in Abaqus explicit | 12 Relevance | 3 years ago | Jorgen | Bergstrom-Boyce Model | |
| Just perform the dynamic model as usual, except that you specify the material model you like to use (*Hysteresis, PRF, PolyUMod). -Jorgen | |||||
| RE: Constitutive model of BERGSTROM-BOYCE MODEL | 12 Relevance | 3 years ago | Melly | Constitutive Models | |
| Frank, I am very much interested in those resources for BB model. It will boost my already picking momentum in learning polymer mechanics. If you don't mind, kindly send me via my email: melliesons@gmail.com Regards, Melly | |||||
| Bergstrom Boyce model for thermoplastics | 12 Relevance | 7 years ago | dvhudson08 | Thermoplastics | |
| I was wondering if there is a way to use BB model to simulate thermoplastics. If yes then how to account for poisson ratio? Will it be via Incompressibilty parameter d? Thanks! | |||||