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.

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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.

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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.

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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.

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Bridget Cunningham March 1, 2017

To provide sufficient support for a rotating shaft or journal, it is important to choose a hydrodynamic bearing design with the right load capacity. If the applied loads are greater than a bearing design can handle, it can cause excessive wear and instability. With the Rotordynamics Module, an add-on product to the COMSOL Multiphysics® software, you can compare the load capacities for different types of hydrodynamic bearings and determine which one is best suited for your particular application.

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Rémi Magnard February 28, 2017

When modeling a structure with beam elements, we don’t use the actual 3D geometry. Instead, we use a line model, which represents the other two dimensions through defining a set of cross-section properties. With the Beam Section Calculator simulation app, we can easily find the properties for a wide range of beam sections from European and American standards. The app also makes it simple to accurately compute the stress distribution for a given set of applied moments and forces.

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Bridget Cunningham January 2, 2017

When a reciprocating engine’s crankshaft is under rotation, self-excited vibrations occur. These vibrations result from the eccentricity of the crank pin and balance masses on the mechanical part. Here, we’ll accurately study the response of the rotors and the orbits of the mass balances on the shaft with the Rotordynamics Module, a new add-on product to the COMSOL Multiphysics® software and Structural Mechanics Module. From these results, you can improve a crankshaft’s design to reduce vibrations, while optimizing engine performance.

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Bridget Cunningham December 26, 2016

Designing MEMS devices, such as piezoresistive pressure sensors, comes with challenges. For instance, accurately describing the operation of these devices requires the integration of various physics. With the COMSOL Multiphysics® software, you can easily couple multiphysics simulations in order to test a device’s performance and generate reliable results. Today, we’ll look at one example that showcases such capabilities.

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Henrik Sönnerlind December 5, 2016

In finite element modeling, you may encounter formulations where a force does not monotonically increase with displacement. You can see this property in many material models that include degradation of the material. Such behavior is represented by a negative stiffness. In this blog post, we discuss some examples of negative stiffness, including the physical backgrounds and numerical implications. These ideas are not confined to mechanical analysis, even though the term stiffness originates in that field.

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Caty Fairclough November 11, 2016

In the highly competitive world of professional cricket, every swing is important. To deliver powerful shots, a batsman needs a well-designed bat and knowledge of how to best use it. One way to improve a player’s batting skills, and perhaps design better bats, is to locate their so-called “sweet spots”. A research team from the University of the West Indies achieved this by performing a structural analysis with the COMSOL Multiphysics® software.

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Temesgen Kindo September 1, 2016

Suppose you take a piece of metal — a thin sheet, for example — and apply some mechanical loads. The metal will deform and take on a new shape that differs from the original undeformed configuration. Say you now want to use this deformed object as part of a new geometry construction. You can then solve another physics problem on the new composite domain. Today, we’ll demonstrate how to use a deformed object as an input to a geometry sequence.

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