## 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.

### Happy Birthday, Nicolas Léonard Sadi Carnot

##### Caty Fairclough June 1, 2015

Happy birthday to the Paris-born “father of thermodynamics”, Nicolas Léonard Sadi Carnot. A talented physicist and engineer, Carnot channeled his interest in steam engines into the creation of a theoretical thermodynamic cycle called the Carnot cycle. Through this theory, Carnot laid the groundwork for the second law of thermodynamics, which relates to entropy and heat loss and is still relevant in physics and engineering today.

### Using a Simulation App to Evaluate Fatigue Life in a Frame

##### 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.

### Modeling of Materials in Wave Electromagnetics Problems

##### Walter Frei May 27, 2015

Whenever we are solving a wave electromagnetics problem in COMSOL Multiphysics, we build a model that is composed of domains and boundary conditions. Within the domains, we use various material models to represent a wide range of substances. However, from a mathematical point of view, all of these different materials end up being handled identically within the governing equation. Let’s take a look at these various material models and discuss when to use them.

### Modeling an Inductive Position Sensor

##### Caty Fairclough May 26, 2015

Cars have to exist in a variety of environmental conditions. They need to handle environmental changes such as temperature fluctuations. Therefore, it is important to create parts that can handle these conditions. An investigation into the functionality of an inductive position sensor was presented during the COMSOL Conference 2014 in Cambridge.

### Simulating UHV/CVD and Silicon Growth on a Wafer Substrate

##### Brianne Costa May 25, 2015

Chemical vapor deposition (CVD) is popular in the semiconductor industry for its ability to produce high-quality, pure, and extremely strong materials. Ultra-high vacuum CVD (UHV/CVD) requires complex equipment and very high temperatures. To increase efficiency and control costs, engineers can simulate this complex process. Here, we use the growth of silicon wafers as an example.

### App: Improving the Payload Capacity of a Truck-Mounted Crane

##### 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.

### Direct FSI Approach to Computing the Acoustic Radiation Force

##### 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.

### Can Models Be Protected by Copyright Law?

##### Mark Robins May 19, 2015

In the science and engineering community, models are vital to design and development. But can models be protected by copyright law? Establishing the level of creativity required for copyright protection is relatively easy in comparison to patent law, which requires inventions to be novel and non-obvious. Additionally, copyright law does not require the secrecy measures needed to qualify for trade secret protection. We explore the appeal of using copyright to protect models and the functionality built around them.

### Creating a Wavelength Tunable LED Simulation App

##### Matt Pooley May 18, 2015

Thanks to the Semiconductor Module and the Application Builder, developing custom optoelectronic simulation apps has never been easier. In this blog post, we show you how to turn a model of an LED device into a user-friendly application that can be used to assess the impact of different designs on the LED’s emission characteristics and performance. We also demonstrate the use of custom methods to manipulate the solution data, enabling the easy creation of bespoke analysis tools.

### Modeling Metallic Objects in Wave Electromagnetics Problems

##### Walter Frei May 14, 2015

Metals are materials that are highly conductive and reflect an incident electromagnetic wave — light, microwaves, and radio waves — very well. When using the RF Module or the Wave Optics Module to simulate electromagnetics problems in the frequency domain, there are several options for modeling metallic objects. Here, we will look at the Impedance and Transition boundary conditions as well as the Perfect Electric Conductor boundary condition, offering guidance on when to use each one.