Singularities in Finite Element Models: Dealing with Red Spots

Henrik Sönnerlind | June 3, 2015

Your finite element model will sometimes contain singularities — that is, points where some aspect of the solution tends toward an infinite value. In this blog post, we will explore the common causes of singularities, when and how to remove them, and how to interpret results when singularities are present in your model. While most of this discussion is in terms of structural mechanics, similar phenomena can also be found in many other physics fields.


Caty Fairclough | May 28, 2015

Simulating fatigue offers valuable insight into how stress can affect the longevity of a structure and its components. This can help identify potential design problems and pave the way for the development of a safer structure. Arriving at this solution, however, often requires running several simulations to test different scenarios. Our Frame Fatigue Life demo app demonstrates how simulation apps can save you time and energy in evaluating the impact of fatigue.


Alon Grinenko | May 20, 2015

In an earlier blog post, we considered the computation of acoustic radiation force using a perturbation approach. This method has the advantage of being both robust and fast; however, it relies heavily on the theoretical evaluation of correct perturbation terms. The idea behind the method presented here is to solve the problem by deducing the radiation force from the solution of the full nonlinear set of Navier-Stokes equations, interacting with a solid, elastic microparticle.


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Henrik Sönnerlind | May 5, 2015

In Part 1 of this blog series, we discussed some of the considerations that you need to make when transforming your measured material data into a constitutive model. Hyperelastic materials were discussed in some detail. Today, we will have a look at how to use nonlinear elastic and elastoplastic materials, and show one way in which you can use your measured data directly in COMSOL Multiphysics.


Phillip Oberdorfer | April 9, 2015

Stirling engines, or heat pumps, are systems that are able to work on incredibly low temperature differences. In fact, some types of Stirling engines only need human body heat in order to operate. Here, we explore the dynamics of this interesting machine that you can build at home and demonstrate how to model it using COMSOL Multiphysics.


Bridget Cunningham | April 6, 2015

When an earthquake strikes, the force from its seismic waves can weaken the stability of buildings. By implementing seismic control measures, designers can enhance the flexibility of such structures as well as strengthen their safety levels. See how one research team used COMSOL Multiphysics to study the impact of base isolation systems and explore approaches to optimizing their performance.


Bridget Cunningham | May 21, 2015

Truck-mounted cranes are designed to handle heavy loads. With this in mind, manufacturers and engineers look to optimize the machine’s payload, or carrying, capacity. Simulation apps can help expedite the optimization process by extending simulation capabilities into the hands of those who are not experts in simulation through a customized and intuitive interface. Our Truck Mounted Crane Analyzer demo app shows the benefits of this approach.


Brianne Costa | May 13, 2015

Piezoelectric valves are opened and closed by stacked piezoelectric actuators that are positioned above a seal. By applying a voltage to the stacked piezoelectric actuator, it can be made to expand or contract and the resulting deformation is used to open and close the valve. In this blog post, we feature a tutorial model of a stacked piezoelectric actuator in a pneumatic valve, new with COMSOL Multiphysics version 5.1.


René Christensen | April 21, 2015

Today we welcome guest blogger René Christensen from Dynaudio A/S. When evaluating loudspeaker performance, dips and/or peaks in the on-axis sound pressure level can be a result of an unfortunate distribution of phase components. To overcome this, we use a phase decomposition technique that splits a total surface vibration into three components depending on how they contribute to the sound pressure in an arbitrary observation point; either adding to, subtracting from, or not contributing to the pressure.


Fabrice Schlegel | April 7, 2015

Today, we compare the Boussinesq approximation to the full Navier-Stokes equations for a natural convection problem. We also show you how to implement the Boussinesq approximation in COMSOL Multiphysics software and discuss potential benefits of doing so.


Chien Liu | April 1, 2015

Over half a century ago, Mark Kac gave an interesting lecture on a question that he had heard from Professor Bochner ten years earlier: “Can one hear the shape of a drum?” He focused on the (then undetermined) uniqueness of the set of eigenvalues given the shape of a vibrating membrane. The eigenvalue problem has since been solved and here we explore the “hearing” part of the question by considering some interesting physical effects.


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