## How to Analyze Eigenfrequencies That Change with Temperature

##### Henrik Sönnerlind May 22, 2017

In some applications, particularly within the MEMS field, it is important to study the sensitivity of a device’s eigenfrequencies with respect to a variation in temperature. In this blog post, we show how to do this using COMSOL Multiphysics® version 5.3. We also explore effects like stress softening, geometric changes, and the temperature dependence of material properties.

### Studying the Artificial Ground Freezing Method with Simulation

##### Bridget Cunningham May 18, 2017

When the German engineer F. H. Poetsch first developed the artificial ground freezing (AGF) method in 1883, he did so to avoid water within Belgian coal mines. The method, which first received praise in the late 1800s, remains similar to its original form and is still valuable today. To develop a more effective AGF method, we can turn to simulation analyses.

### Introduction to Modeling Stress Linearization in COMSOL Multiphysics®

##### Henrik Sönnerlind May 16, 2017

In some applications, it is necessary to approximate a general 3D stress state by a set of linearized stresses through a cross section of a thin structure. This is important for applications like the analysis of pressure vessels, fatigue analysis of welds, and determination of reinforcement requirements in concrete. In this blog post, we discuss why such an approach is useful as well as how to compute linearized stresses in the Structural Mechanics Module for COMSOL Multiphysics® version 5.3.

### Modeling a Transient Contact Problem with Stick-Slip Friction Transition

##### Bridget Cunningham May 3, 2017

For many mechanical contact problems, stick-slip friction transition is an important point of analysis. When present, this phenomenon influences the stresses, strains, and deformations near the contact area between the two bodies. In version 5.3 of the COMSOL Multiphysics® software, we have the tools necessary to handle this type of mechanical contact problem and validate the results. With a better understanding of stick-slip friction transition and its subsequent effects, we can improve the safety and energy efficiency of relative systems.

### Analyzing Heat and Mass Transfer During Cake Baking with Simulation

##### Bridget Cunningham April 26, 2017

Sometimes when you bake a cake, it doesn’t turn out how you expected. Part of this is due to the underlying heat and mass transfer phenomena that occur within the baking process, which affect the end result. With tools like the COMSOL Multiphysics® software, you can study and predict how these mechanisms work and use this knowledge to bake a better cake.

### Analyzing the Mechanical Performance of a Tricycle Frame Design

##### Caty Fairclough April 19, 2017

Human-powered vehicles like tricycles can provide a sustainable alternative to passenger vehicles and help riders avoid traffic in populated areas. Before a tricycle design is ready to roll, it needs to be optimized to meet safety requirements, which can prove difficult due to the complex structure of the tricycle. To efficiently pinpoint weak areas in a tricycle frame design, a research team used the Structural Mechanics Module with the COMSOL Multiphysics® software.

### Studying the Influence of Concrete Phenomena on Sensor Performance

##### Bridget Cunningham April 12, 2017

Many parameters can impact the strength and stability of concrete structures, so finding ways to efficiently measure their condition is key. Embedding sensors within these structures can provide such assessments. To accurately model these systems, it’s important to account for the complex phenomena within concrete and analyze their impact on sensor performance. The flexibility of the COMSOL Multiphysics® software allowed one research team to do just that. Their findings offer insight into designing more reliable sensors for concrete monitoring.

### Predict Thermal Drift in Microwave Filters Using Multiphysics Simulation

##### Caty Fairclough April 11, 2017

Microwave filters can help prevent unwanted frequency components in the output of a microwave transmitter design. However, when the microwave system experiences thermal drift, it can be difficult to achieve high-frequency stability in the filters. To address this issue and improve filter designs, system engineers need to predict the change of the passband frequency caused by thermal expansion. As we’ll see today, one way to achieve this is with multiphysics modeling.

### Using Low-Reflecting Boundary Conditions to Model Wave Propagation

##### Bridget Cunningham April 6, 2017

Modeling the propagation of waves from a large vibrating structure can be a challenging task. It requires balancing the reduction of the computational domain’s size with the decrease of reflection at surface boundaries. With the low-reflecting boundary conditions in the COMSOL Multiphysics® software, we can easily reduce our computational domain to a practical size while ensuring accurate simulation results. Today, we illustrate this with the example of modeling wave propagation in rocks under blast loads.

### Designing a Sensor Package for a High-G Accelerometer via Simulation

##### Bridget Cunningham March 28, 2017

Measuring acceleration is important in high-speed dynamics, as velocity, force, and pressure are derived from it. Sensing elements inside accelerometers make it possible to obtain such measurements. As technology advances, these sensor packages must be optimized to handle higher vibrational frequency bandwidths. To accomplish this, researchers tested their novel piezoresistive sensor chip as part of a package design. Their simulation results, which agree well with experimental data, pave the way for optimizing sensor packages to achieve higher bandwidths.

### Understand Phenomena in the Viscous Catenary Problem via Simulation

##### Bridget Cunningham March 22, 2017

The viscous catenary problem has generated a lot of theoretical and experimental interest in recent years. This is due to the industrial importance of the rich phenomena that occur within it. Using the flexibility of the COMSOL Multiphysics® software, we can gain fundamental insights into complex problems like the viscous catenary problem and determine the validity of the assumptions made in previous analyses.