Questions related to Numerical Simulation
I am currently dealing with a non-convergence problem during meso-scale numerical simulation of a three-point bending test of concrete using a random aggregate model in ABAQUS, where the material chosen is a concrete damage plasticity model that is embedded in ABAQUS, and the load-CMOD curves obtained are incorrect, with a peak load of only about 60N. However, I got the correct results using the same material properties for the compression numerical simulation. In 3TB the contact between the support, the loading device and the specimen is face to face contact.
Please advise me what I should do next to modify the model?
I am trying to model a process in which there is a flow of non-newtonian Herschel-Bulkley fluid. to derive equations of pressure drop, wall shear stress and drag force(for spheres inside the fluid) i need a form of reynolds number for herschel bulkley fluids.reynolds number should consider existence of yield stress in rheogram of fluid.
so is there any generalized form of Reynolds number that is applicable for herschel-Bulkley fluids??
I surveyed previous works but i didn't finds so much about
When utilizing COMSOL for numerical simulation of electrokinetic remediation of heavy metal contaminated soil, is it possible to obtain electroosmotic flow？
For simulating a time periodic flow, I increased simulation times up to 100s and use adaptive time steps.
But I didn't get desire result...I checked simulation setup several times...I don't know why CFX results are different from Analytical solution?
CFX simulation take about 20 days.
*may be by increase the simulation time get a better result!
what do you think?
I am trying to simulate methane-air combustion in Ansys Fluent using EDC model and GRIMech 2.11 detailed mechanism(277 Reactions and 49 species) but i get no combustion. Any suggestions to solve this problem?
- Pressure-based solver
- Realizable k-epsilon model
- Species transport model with EDC model
- Air and CH4 enter chamber from 1 inlet in 2D model at 673K
- Inlet is velocity boundary with swirl component and outlet is pressure boundary
i also tried patching temperature, reactants and products.
Our paper on the subject shows that using the appropriate injection frequency, yes it is possible.
Our work is based on numerical simulation in simplified domains, using LBM. I hope it stimulates application engineers to develop the technology to facilitate the energy transition. Thanks for sharing it.
Our paper is free for 50 days at:
If numerical simulation is not carried out only experimentation has been done in that case is it possible to publish a paper after doing numerical simulation?
I performed the numerical simulation of friction welding on ABAQUS software. Finally, the deformation and temperature distrubtion were recorded on the tool instead of the welded plates. I wonder if anyone can give me some ideas for this problem. Instead of finding stress and strain on the welded plates, I have results on the tool.
I simulate a periodic structure placed on a lossy, dispersive half-space whose relative permittivity is smaller than zero at some frequencies. Using CST 2020, I apply open boundary condition (without adding space) in the direction filled with the mentioned medium.
However, the simulation doesn't progress due to the errors. These errors are as follows:
1) "The Floquet port boundary at Zmin must be homogeneously filled with isotropic loss-free and non-dispersive material. For non-dispersive materials, please consider using the option to "Ignore losses" in the solver specials.".
2)"The Floquet port boundary at Zmin has negative material coefficients, which are not supported."
Curious to know the reason. Does it belong to the software limitations or sth?
Any suggestions or ideas are appreciated.
A 3D numerical simulation project involves a turbulent flow of water in a tube with a constant heat flux entering the surface.
This numerical simulation needs to be validated by a similar article that has simulated the K-Omega SST Turbulence model.
Please guide me if there is an article I can refer to.
Hello, Dear All
Has anyone done numerical simulation using ANSYS FLUENT software for non-Newtonian flows such as Bingham for example "drilling fluid" that can help me in case?
My Question: What is the range of Herschel-Bulkley Parameters such as: Consistency index (k), Power law index (n), Yield stress and Critical shear rate in these fluids? If you know the reference in this case to help me, Please let me know?
Thank you for your consideration
There are several rheological models available in literature for mathematical modelling of Magneto-rheological Fluids. So, which model gives the best solution for numerical simulation? Here best solution means good/close agreement for the experimental results.
I am working in numerical simulation and analysis of heat source models using Petrov-Galerkin method. I would expect the best and most suitable software for PG method please
Using COMSOL software to realize the numerical simulation of multiphase flow problem, in the field of microfluidic research, how to realize the simulation of the dynamic contact angle of droplets?
I have modelled a transient flow in a microchannel in ANSYS FLUENT using 100 timesteps. I want to export the velocity at each node in excell format for all timesteps simutaneusly. Although using the export command i can only do it for each time step individually . Please advice me how to extract velocity for all timesteps simultaneusly in excell format (does not matter if there is a diferent excell file for each timestep).
I think I have all the settings (in terms of boundary conditions) right and I get a converged solution with reasonable values for poisson and Nerns-Planck only. When I add Navier-Stokes it converges but the results are nonsensical. I think the issue might be how I the equations are solved in the stationary study. Can anyone tell me the sequence in which these equations are solved in their Comsol models? By the way I have version 4.3a.
In ABAQUS, I want to model a bent tube with varying thicknesses and diameter (continuous linear function) from one end to the other. I have attached a sketch with the question for better understanding.
Later I want to hydroform it into an even more complicated shape, therefore meshing, surface definition, and boundary condition definition are important. It is not a challenge for modeling tools like SolidWorks, CATIA or ProE but importing part from there is a mess and even if somehow import is successful, meshing, surface interaction definition, and BC definition is problematic. Therefore, it would be great if I can directly model it in ABAQUS.
I tried 3D/Shell deformable sweep command but it only asks for a sweep geometry at then sweeps the geometry along the defined path continuously, while I want to vary the thickness and diameter linearly.
Is there a possibility to do that?
I am working on numerical simulation of ultrasonic wave propagation through an elastic medium without any defect. I calculated the velocity of wave by using time and distance relationship. But when i used model with void or crack, i got less time to detect the first wave, while it should be longer as there is hole in model and wave propagation through it should be more. Can anyone help me out this problem i.e. how wave velocity is calculated in the model with defect.
I am trying to model excavation procedure of tunnel (D-shaped) in Abaqus (CAE). I have obtained the RF1 and RF2 from an independent analysis as given in Abaqus example (Abaqus example problem guide/1.1.11 Stress-free element reactivation). Now, my problem is that how to apply those concentrated forces ((2n+1)*2) on corresponding nodes?... Because, in my model total number of nodes (2n+1) on tunnel periphery are 129 (in the abaqus example, there are only 13 nodes). And, its changing with each trial/variation of mesh size.
So, how should I apply the concentrated forces?
i) one by one clicking each node, creating each node a set and then applied the loads from load module ? (it's tedious/repetitive. I don't want to do it) or
ii) Doing some editing in *.inp file? (But, when I tried with following format, ABAQUS is simply neglecting my edited lines:
node number, direction, magnitude) or
iii) writing ULOAD subroutine?
Please clear my doubts.
Thanks in advance.
Recent numerical simulations show that the inner part of the disk seems to oscillate in presence of a Large scale magnetic field or when the disk is in MAD state. So, can we correlate this sort of behaviour with the variability of the source?
I need to do numerical simulations such as phase plots, bifurcation diagrams, parametric basins of attraction, and Lyapunov exponent diagrams. I already have the fixed points though.
I have read many publications using FE model to study interfacial behaviour. And Few of them considered matrix viscoelastic effect in the studies. I seems that most authors avoid to discuss about this.
I have a lab combustor on which I did some experiments and obtained some flashback data in terms of equivalence ratio at various flow conditions. i want to simulate the reacting flow field at those flashback data points.
Please help me with some literature which can help me perform those simulations using ANSYS Fluent 18.
i had done some work about the debris flow through the experiment and numerical simulation using PFC3D.the particle velocity cloud figure of particle flow could't be well displayed to the reader.
My objective is to model the stress-relief mechanism of a clayey meter scale experiment.
Please, share published material and your suggestions for such a small scale experiment.
Paleomagnetic studies show that the South China block was moving northward continuously from 300 to 260 Ma and has experienced an overall ∼27° clockwise rotation since then (Huang et al., 2018) ,and assuming a stationary Emeishan mantle plume, so if I want to do a numerical simulation of the geodynamics of the Emeishan mantle plume based on the above conditions. How can I do it?
Higher-order basis function (HOBF) settings are ignored when are used in conjunction with planar multilayer substrates in FEKO. Does anyone know how can i activate a similar setting?
Thanks in advance
My field of expertize is in CFD and not in climatology. But I would start a discussion about the relevance of the numerical methods adopted to solve physical models describing the climate change.
I am interested in details in physical as well as mathematical models and the subsequent numerical solution.
I was looking for some literature on translational dynamics of particles (irrespective of their shape) in viscous sublayer, and unfortunately did not find any useful information. It is well known that, particles move faster than the fluid in the buffer layer but, the question is do they move faster or slower than the fluid in the viscous sublayer?
I would appreciate if someone can direct me towards some published research articles (both numerical simulations and experimental).
I need to simulate Electrical double layer (EDL) in comsol to achieve more accurate results for my parallel microchannel. the fluid is water and channel is made of glass. it seems that for modeling EDL in comsol I should Couple Laminar flow, Electrostatics and transport of dilute species physics. but I cant do this.. What should I Do? is there any kind of tutorial media for this topic?
I am developing a reactor model and it is required that I employ thermal conductivity, heat capacity and diffusivity as properties that change with temperature. Most COMSOL examples seem to specify these properties as fixed parameters rather than as a variable. Could you describe to me how this can be achieved in COMSOL? References to specific pages in the COMSOL user guide or COMSOL tutorials/blog that explain this will also be appreciated.
I asked this a while ago, but decided to dig a little deeper before asking again. When using the Abaqus JH1/JH2/JHB Johnson-Holquist models for brittle materials, the FS (Failure strain) element removal threshold value is extremely important to ensure the simulation matches experiments, yet in practically all of the studies I have looked into, none of them have reported this FS value despite its major significance.
In the Abaqus documentation, FS was given as 0.2 for SiC. Subsequent studies on alumina have claimed that this FS value needed to be adjusted for accuracy, but then never reported it (e.g. Liu et al. 2015; Khan et al., 2021; Guo et al. 2020; Goda & Girardot 2021).
If anyone can shed some light about what this FS value is meant to be and how to obtain it experimentally or analytically, I would love to understand it better. Thank you!
I am working on Numerical Simulation for Cold Crack prediction in additive manufacturing and looking for a way forward to do FEM simulation with ABAQUS. Generally, cold cracks produced in the presence of hydrogen so I wonder if there is a straightforward solution for hydrogen diffusion or crack prediction with FEM. Thank you in advance
I'm making a series of numerical simulations which the response is a curve of a determined variable along time, for exemple, y(t).
Basically, I have 5 parameters of control which I need to vary to obtain an response on my response variable. For exemple, I need to test three different particle diamenter and three different Reynolds number and obtain 6 curves to my response variable, which is a curve in the form y(t), which t is time.
I know that experiment design can help me with it. But I do not understand how can I correlate a curve as a function of time, and not an specific value. Most book exemples I was able to find correlate an specific value and I was not able to extrapolate from that.
Not sure if I was clear enough, but can someone help me with that?
I am working on FEM Simulation of Crack Susceptibility in PBF additive manufacturing. Perhaps, Could not find a way to evaluate residual stress threshold value for crack prediction through numerical simulation. I look forward to your answers
In my paper, I simulated a PSC with different HTLs. The Jsc of different configurations were close to each other. However, the QE curves for the inorganic HTLs overlapped, except for organic HTLs. What can be the reason for the fluctuation of QE curves regardless of the close values of Jsc?
The same phenomenon happened in figure 4 of DOI: 10.1016/j.rinp.2020.103707, but there was no explanation. It will be much helpful for me if you kindly suggest me some references regarding this with your valuable comment.
I am attaching the QE curves for different HTLs and the Jsc table of my paper herewith. The arXiv preprint link of my paper is
When planning and designing buildings, and urban environments, especially cities with many high-rises, simulating airflow is an important tool for studying how the city’s layout might affect expected temperatures, among other things. Other areas of use include modeling and predicting wind load on buildings to study Fluid-Structure Interaction(FSI). The local climate around a building in an urban environment can differ significantly from the more general weather data often used in the computation. Consequently, local wind and temperature conditions affect heating and cooling as energy requirements for buildings. However, there is still a stumbling block. Existing simulations use extremely simplified geometric descriptions of the urban environment, which results in poor computational precision. (The photo has been taken from Chalmers university of technology.)
I am working on numerical analysis of the Friction Stir Welding (FSW) process using Abaqus. The model compressed of johnson cook flow model, ALE Adoptive Remesh to avoid distortion problem, Mass scaling to increase computational efficiency, Temperature-dependent material properties, modified columns law with the temperature-dependent friction coefficient, a shoulder to pin ratio of 3, assumed tilt angle as 0 in the present case, and trying to simulate the Plunging, Dwell, and welding phase of FSW.
Plunging, Dwell is happening as expected. However, on entering the welding phase, the material retrieves aren't taking place and leave a dent, as shown in the attached file in all cases of different rpm and travel speed. This looks like permanent deformation of material without material retrieval during the process. Kindly suggest relatable suggestions on how possibly these issues can be solved using Abaqus... I really appreciate any help you could provide.
#FSW #Abaqus #Friction Stir welding #ALE
I would like to consider corrosion in a column in my numerical simulation in ABAQUS? Can I just decrease the stiffness to simulate the corrosion? or any change in mechanical properties?
Is there any reference or paper or guideline about numerical simulation of corrosion specially in the steel or RC columns?
I am interested to perform spectral analysis of a structure under random waves. could anyone suggest me a book or an example that starts from wave spectrum (such as
JONSWAP spectrum , P-M etc) to RAO. A complete example from formulation to numerical evaluation.
I submited a manuscript to Communications in Nonlinear Science and Numerical Simulation, and would like to list the reviewers in this journal.
Thank a lot .
I'm performing a cryogenic turning process.
The temperature are recorded from the thermal imaging camera.
Can I use these temperature values to simulate the flow characteristics and behaviour of the cryogenic coolant?
Is this an acceptable thesis?
Thank you in advance.
As you might know, the centrifugal compressors can experience surge at low flow rates.
Surge detection is possible using experimental measurements and/or numerical simulations.
In the numerical simulation, the compressor's outlet pressure or mass flow rate starts to oscillate as the flow rate gets closer to the surge margin.
Is there any quantitative criteria for the amplitude of oscillations at which the flow rate can be considered as the surge margin? In other words, how mush oscillations are allowed in the safe operation of a centrifugal compressor?
I would like to estimate the fatigue life of the composite through numerical simulation. please help me with how to write code for low cycle fatigue in Abaqus.
High fidelity simulations create an enormous amount of data that can mimic real-world values with excellent accuracy with modern tools and much of this is discarded as "too sanitized" for use in deep learning. But in cases where datasets are very lopsided, such as when a true positive is hard to obtain or rare to observe but true negatives are abundant, isn't sanitized synthetic positive data better than nothing?
In my current project, using an FEM model of the brain/skull system we are using the simulations of head impacts to supplement data from athletes who wear smart mouth guards in an attempt to gather important statistics for early concussion detection. This extra source of true positives has helped improve the overall performance of the ML platform that analyses signals coming from the mouth guards, but it isn't a perfect solution.
I would like to be provided with the articles that you think simulated heat and mass transfer of droplets in condensation in the most accurate way. I am interested more in the simulations containing both fluid and vapor phases. Please recommend articles with numerical simulations, not analytical approaches.
I am dealing with quasi-static compression simulations on topology-optimized lattice structures using the Abaqus Explicit solver.
By the way, I have not modeled material failure model for several reasons and the material model I've used includes Johnson-cook plastic parameters for AM-SS316L. Now here is my question:
How important and effective is modeling material failure in this case? does it effectively change the stress-strain (force-displacement) curves trend?
If yes, what is your suggestion for material failure model of SS316L in Abaqus? Is there any easier way rather than finding J-C damage parameters for SS316L?
It would be great if anyone can help me to find these parameters.
I encountered some problems when using the ABAQUS CDP model. Could you please give me some suggestions?
I did a monotonic uniaxial test using a single 3D solid element (C3D8R) and the CDP model. As shown in the picture attached, if tension damage is defined the maximum principle stress vs maximum principle strain relation shows strain hardening compared to the input data, while the stress and strain curve matches the input value if tension damage was not introduced. This is kind of strange as material damage should not have an effect on the stress and strain relation under monotonic loading.
Moreover, when the plane stress element (CPS4R) is used, the stress and strain relation is identical for cases with and without damage as it should.
I have also attached the input files for both the 3D and 2D models. I will be grateful if you could give me some advice.
Hi, I entered the equations for a CPVT collector in ees and linked the model to TRNSYS to use in my simulations, the inputs (ambient temperature, atmospheric pressure and wind speed) are given to the model by Type109-TMY2, but the input for radiation (beam or total) is given zero and causes the model to not work properly. Does anyone know how to fix this? (The TMY2 file has no problem and works well with other components)
I am trying to simulate the time-dependent corrosion of underground concrete structures. I'm looking for easy-to-use software that can handle such models. I know that common numerical simulation software (such as ANSYS and ABAQUS) can be used for this purpose. However, I am looking for a more straightforward and simple simulation tool specifically developed for such models.
With the limited ability of personal computers, it is often impossible to do numerical calculations because it involves a very large number of cells, for example, with 10 million cells. This problem is usually experienced when facing problems with large geometric sizes. What do we do to reduce the number of cells in a numerical simulation, but give good results?
Dear respective researchers, please give your reply for this case.
Thank you very much for your reply and contributions.
Since the unfortunate appearance of COVID-19, there has been a massive number of mathematical models based on the SIR or SEIR models. A perusal of these has shown that the models are mainly numerical simulations to predict the course of the outbreak under varying conditions. Would an understanding of the disease dynamics be improved if equilibria or bifurcation analysis was incorporated?
To analyze the thermal stratification of solar hot water storage tanks using numerical simulations, is it possible to apply the turbulence model? What are the parameters of using the model?
I'm training to make a numerical simulation for differents poisson's ratio which are varied between [0 0.1 0.2 0.3 0.4 0.5]. I need the references that contain their densities and young's modulus.
I would like to do the numerical simulation of an automobile catalytic converter and for that I need some input data such as viscosity, temperature, velocity &... of the exhaust gas. does anyone have access to this data to help me.
I´m working in a numerical simulation of the deformation of a thiourethane during annealing (stress relief) but at this moment I dont know the mechanical properties of the base material, so i want to use the shear and elastic modulus from DMA tests, it could be correct?
I can´t obtain the same results in Fresnel coeficients of a materials with complex refraction index (bi-layer dielectric thin-film) with angular incidence.
Hi, I'm modeling shear critical beams, some of them have stirrups and some don't. I got excellent results for the specimens without stirrups and low load capacities for those with stirrups. It looks like adding the stirrups didn't have any effect at all.
I then realized that if I load only the reinforcement (without the beam) the stirrups move independently from the rebars, looks like they are not connected.
How can I connect them properly? I tried using tie interaction but it didn't work as I expected.
Thank you in advance,
I would like to characterize p-type semiconductor/Metal shottky barrier to study the activation energy Ea of the SC defects. Is there a way to make C(V) or C(F) by numerical simulation tool?
Is there anyone to guide me on how to find a reference geometry of the nasal cavity to validate numerical simulations?
I am working on an algorithm that receives 4 pulsating inputs to produce two continuous outputs. A numerical model that enables numerical simulation is all that I have in hand. However, the practical value of the system can't be assured unless a stability analysis can be conducted. My question is: how to assess such algorithm stability while I don't have a dynamic model of the algorithm in the frequency domain?
I want to numerically simulate a planar solar thermophotovoltaic in matlab. As I searched, could not find complete and detailed formulation for this work. Does anyone have a complete reference or give me a detailed energy balance for the components?
also is it better using simulink platform or writing a detailed code?
I am working on Mathematical Modelling project and looking to using some mathematical tools that they are widely used in cancer models.