Variable time stepping
Hi Would you help/suggest me on how to set up a variable time stepping scheme in a time dependent solver ( COMSOL 4.2a) Thanking you in advance
View ArticleDeformed geometry from one step does not carry-on into the next study step ?
Hi all, I recently started using V4.3. My model, involving two physics, has three study steps in one study where the solution of previous steps fed to the successive steps as initial conditions. In the...
View ArticleERROR: nonlinear solver did not converge, when simulating ball movement in...
Hi all, I have seen several threads about this error and tried to figure it out myself using the sample cases but I still fail to simulate this. Any help will be greatly appreciated. I am trying to...
View ArticleUndefined value found
I had great trouble meshing a geometry. After I refined the mesh and was finally able to mesh it, I clicked the compute button. 78 seconds later, I got this message: Undefined value found. - Detail:...
View Article2D TRANSIENT Heat Transfer Problem
Hi everyone, I am encountering an error in the time dependent situation - Failed to find consistent initial values, last time steps not converged. I have specified 'initial values' and the required...
View ArticleAcoustic Band Structure of Metamaterials
Hi folks, I have been trying to find the band structure of an acoustic metamaterial. I have been attempting to adapt the "Bandgap analysis of Photonic Crystal" tutorial given for COMSOL 3.5a to 4.3. I...
View ArticleUnidirectional coupling of a time dependent study to a stationary study
Hello, I am using structural mechanics module and a stationary study to calculate stresses and strains in a simple 2D axi-symmetrical model. The model has a thermal expansion node. I have another study...
View ArticleCritical force to bend a cylinder
Hi, I have a cylinder attached to the top of a block (bottom of the block is the fixed constrain). Uniform load is evenly applied along the entire length of the cylinder, and faces the same direction....
View ArticleMean operator requires an adjacent entity of higher dimension
Hi, I am modelling a 3D DC discharge plasma model, My model is a lil bit complex and i have followed the same steps as a 2D DC discharge plasma model. Everything is built but when I try to compute the...
View Article1D plot: plot height in function off it's width (2D geometry)
Hello, I was wondering if there was a built in function to plot the height of a geometry in function of it's width. I thought this would be specially interesting if it was possible to plot this when...
View ArticleTransient Simulation - Continue option
I have ran my transient simulation from 0 - 900 s with 1 s time step. Now I want to continue the simulation from 900 s - 960 s with 1 s time step. How to do this?
View ArticleError: Internal error: cannot convert ElemStruct to double
Hi everyone, Since this morning I have this error on my computer for all simulations where I use periodicity boundary conditions: Error: Internal error: cannot convert ElemStruct to double. It involves...
View ArticleEvaluate a path integral
Hi, I need to evaluate a path integral of a known function f(x,y,z). The path p(t) is a solution of an ODE. dp/dt = E(x,y,z) p(0) = p_0 Here, E(x,y,z) is an electric field solved from a previous...
View ArticleHow to couple two physics model both are time dependent and affect each other
Hi, I have a problem like this. For a simple description: model 1 (corrosion): F1=(X1,X2,X3, F2, t), for example F1 is corrosion depth, F2 is stress model2 (solid mechanical ): F2=(Y1,Y2,Y3, F1, t)....
View ArticleHelmholtz coil not solved correctly
Hi, I am a beginner in Comsol and I am trying to solve for an anti-helmholtz coil configuration. I followed the instructions given in the help manual but the solution seems to be wrong. Furthermore,...
View ArticleCOMSOL 4.4 client / server version mismatch
I'm trying to connect to our remote server (headless Linux box, running COMSOL 4.4.0.248) from my desktop (Mac under Yosemite, running COMSOL 4.4.0.361) to solve a large magnetostatic problem. Both the...
View ArticleWhy "Tin Melting Front" tutorial don't work with stationary solver?
Hello! There is an interesting question. I study the tutorial model "Tin Melting Front". This is Time depended model as it presented. However, this problem obviously has a stationary solution. So, why...
View ArticleModeling LiIon Battery Load Cycles
I've been working with the lithium ion battery module quite a bit, and I keep running into the same problems - load cycle discontinuities are making the solver spit out errors left and right. I've...
View ArticleSimulate elastic substrate
I am very new to Comsol and trying to simulated a elastomeric substrate with nanoparticle filled in it. I have following problems I simulated only a rectangular film made of elastomer. I applied load...
View ArticleSimple solid mechanics problem
Hi everyone! I'm trying to solve a simple two-element steady-state solid mechanics problem, shown in the attached picture. The elements are both Q4 elements. The displacements should be {u,v} = {0, 0},...
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