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Error: 7161 The mass matrix is zero - resolve

Respected sir/ma'am, I am trying to simulate a Nano ElectroMechanical Switch(NEMS) using the following modules:a)solid, stress-strain, b) Moving Mesh, and c)Electrostatics. When i run the solver, it...

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failed to evaluate variables

Hi , I am building a 3d model of fluid flowing around a wafer using 4.3a. The following error occured when I tried to plot the pressure on the edge of the wafer. Cannot ecaluate expression. Failed to...

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different physics with different meshes in 3D

Hello, I work on a casting model with a phase change in a metallurgy process. The 2D-axy model works fine and i begin the 3D model. I work on a 3D coupled problem with different physics: mf for...

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Electric field between electrodes

Hello I am trying to make a very simple model to calculate electric field between two electrodes in water facing each other(using electrostatics module). I set for the electrode boundaries opposite...

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Avoiding Negative Concentrations

Hello, I would like to make sure that my reaction rate is such that when the concentration of the species approaches zero, then so does the species sink. Comsol Says: This can be achieved for instance...

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modeling nanostructured organic solar cell with Comsol

Hi,how can I modeling Zinc oxide nanostructures organic solar cell in which include the effects of optical interference, exciton diffusion, charge separation via the formation of polaron pairs, and...

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Piezoresistive modeling

Hello all I want to simulate a piezoresistive beam with Comsol. I was looking to find an example of piezoresistive modeling to find out what module they usually use and how are the settings but i...

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Problem about Joule heating and thermal expansion

Hi I want to inject ac current (amplitude is fixed) to a silicon beam and hope to see maximum expansion when the ac frequency is at half of the mechanical resonant frequency of the beam. I tried using...

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Mie scattering in 4.3

Hello, I have already seen some discussion about mid scattering of a gold nanosphere. But I the discussions I have consulted, no one has yet implemented a mie scattering program in Comsol 4.2 or 4.3...

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New "Introduction to COMSOL Multiphysics" book now available

Hello, We are pleased to announce that a new version of the "Introduction to COMSOL Multiphysics" book is now available for immediate download...

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Electrical resistance in a structure

hello everybody, I need to have a simulation of electrical potential in 1D beam elements in a structure. I want to give potential to one point of the model and ground to another point and observe the...

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Problem in my Results

Hello everyone, I'm having a problem simulating a cylinder of copper. The surround of it is a cube with PML and scattering condition. But my results (attached) seems a little strange. Can anyone help...

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Output pressure of the transducer in frequency domain

Hello,everyone I'm doing research in capacitive ultrasonic transducer. I use the electromechanic model and want to observe the output pressure in the frequency domain. Now I can add the biased voltage...

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Simulation of leakage flux from transformer

Hello. I've tried to simulate a quantity of leakage flux from transformer by using COMSOL 4.3a. To do this, I made a simple transformer model with LiveLink for AutoCAD.(I want to attach mph file, but...

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bistatic radar cross section

Hello! I studied the given tutorial related to radar cross section. Unfortunately, these only provides how to plot monostatic RCS. I tried to use parametric sweep, but it wasn't successful. Can I get...

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Magntic field analyses using current excitation

Hello, I have started to use Comsol this week and have done some examples, but when I try to simulate my model I hit some set backs. The model has 16 electromagnetic poles with a pair of coils in...

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AC/DC training courses in Phoenix, AZ and Burlington, MA

An invitation is open for our Discussion Forum readers! You are invited to attend one of our upcoming AC/DC focused training courses that will take place within the next few weeks. The first course...

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Tightly folded Inflatable structure deployment simulation possible in comsol ?

Hi, We have a problem where we need to simulate the deployment of a tightly folded inflatable structure. I have used explicit ALE method in a different software to achieve this, however it takes a long...

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Temperature effect in Electrostatic module.

Hi, I am using Comsol ver 3.5a. Can anyone guide me that how could i observe the effect of temperature on capacitance value in Electrostatic module ? From where i can change/control the temperature in...

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Gaussian heat flux

I want to use Gaussian heat flux in Comsol 4.3. 1.As given in this module we are using function gp1 but what is the position and standard deviation values for it. 2. Is it necessary to have...

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