## Structural Mechanics Tutorials: Adding Initial Strain and Thermal Stress

##### Andrew Griesmer April 4, 2013

Back in January, I presented a video tutorial introducing the Structural Mechanics Module here on the blog. The video described the steps necessary to perform a static linear analysis on a bracket geometry. Now, to help you better understand the extra functionalities that exist within COMSOL Multiphysics and the Structural Mechanics Module, we are also creating additional tutorial videos of this bracket. The first two “mini-tutorials” to accompany the static linear analysis video focus on adding initial strain and thermal […]

### Structural Analysis with Thin Elastic Layers

##### Chandan Kumar April 3, 2013

Some structural applications involve thin or high aspect ratio structures sandwiched between other relatively low aspect ratio structures. For example, if a piezoelectric transducer is glued on the surface of a mechanical system, the thickness of the adhesive layer is very small in comparison to the two structures it glues together. Numerical modeling of such a thin layer in two or three dimensions requires resolving it with an appropriate finite element mesh. This can result in a large concentration of […]

### The Graphene Revolution: Part 2

##### Daniel Smith March 27, 2013

In a previous blog entry I discussed some of the exotic properties of graphene. The fact that graphene consists of a single layer of atoms means the aspect ratio of any graphene-based structure may be very high. High aspect geometries present their own array of modeling challenges.

### Modeling Temperature of a Wine Cellar

##### Valerio Marra March 26, 2013

A lot of effort is put into inventing or improving existing technologies used to cool buildings, food, or any goods that need to be stored at a definite temperature. The reason is simple: adopting more efficient designs will result in achieving the same goal while consuming less energy. Both our balance sheet and the environment will benefit from these solutions. Here we will explore modeling temperature of a passive cooling design using a wine cellar as an example.

### Acoustofluidic Multiphysics Problem: Microparticle Acoustophoresis

##### Mads Herring Jensen March 7, 2013

The use of acoustic waves to manipulate suspensions of particles, such as cells, has inspired the work of many researchers, paving the way for the field of ultrasound acoustofluidics. The manipulation is achieved in many ways, including using bulk acoustic waves (BAW) and surface acoustic waves (SAW), as well as acoustic radiation forces and acoustic streaming-induced drag. The latter two combine to produce the acoustophoretic motion of the suspended particles; i.e., movement by means of sound, and the methods provide […]

### Simulating Heating of Brake Discs in a Car

##### Fanny Griesmer February 27, 2013

Cars need brakes for obvious reasons, and you don’t want these to fail. Brake failure can be caused by many things, one of which is the overheating of the brake’s disc. As I’ve said before, no engineer wants to design a product that fails, which is also true in the case of brake-disc design. Let’s study a scenario of a car in panic brake mode, and find out how hot the brake discs and pads get as well as how […]

### Electrical: The Bumblebee Electrifies Anyway

##### Phil Kinnane February 22, 2013

“The Bumblebee Flies Anyway” was a book by Robert Cormier that I read as a young teenager. In it, Cormier describes how bumblebees are natural anomalies as they seemingly do not have the aerodynamic capability to actually fly. Their wing span and flapping speed should not provide enough lift to allow flying, and this is a fact that I have always associated with bumblebees since. Yet, this has been proven not to be true, as a closer investigation of the […]

### Long-time Multiphysics User on COMSOL for Heat Transfer

##### Phil Kinnane February 21, 2013

Having used COMSOL Multiphysics for over six years now, we are pleased to have Dr. Jon Ebert, Director at SC Solutions, join us in the next Mechanical Engineering Magazine Webinar Series titled “Heat Transfer in Solid and Fluids”. On March 7th, he will co-host an instructional webinar together with COMSOL’s John Dunec. Dr. Ebert will discuss SC Solution’s simulation activities within a wide span of heat transfer-related applications, particularly with respect to semiconductor manufacturing. As a long-time user of COMSOL […]

### Upgrading the Nuts and Bolts of the Electrical Grid

##### Andrew Griesmer February 20, 2013

The electrical grid describes the network created for producing electricity, transmitting it and delivering it to the consumers. A “smart grid” is an electrical grid that gathers information on the suppliers and consumers automatically to improve efficiency and sustainability in the system. As the automated technology improves, the hardware that physically connects the electrical grid together must improve as well. This hardware, the “nuts and bolts” of the grid, is comprised of transformers, cable joints, terminations, bushings, and fault current […]

### Infamous Failures of Fatigue

##### Fanny Griesmer February 7, 2013

If you’ve studied structural mechanics you’re probably familiar with stories of planes falling out of the sky due to fatigue (no one wants to be the engineer who designed an airplane that crashed…). Jimmy Stewart made a famous movie about that, but different from the usual horror stories of fatigue is the accident in 1919 of a storage tank that burst in Boston, spilling molasses onto the streets at 35 mph (56 km/h). The Boston Molasses Disaster, as it’s referred […]

### Joule Heating Simulations Tutorial

##### Fanny Griesmer January 29, 2013

One of the classic multiphysics couplings in engineering and science is Joule heating, also called resistive heating or ohmic heating. Some Joule heating examples include heating of conductors in electronics, fuses, electric heaters, and power lines. When a structure is heated by electric currents, the device can reach high temperatures and either structurally degenerate or even melt. The design challenge is to remove this heat as effectively as possible. COMSOL eases these challenges by providing a specialized multiphysics interface for […]