Studying Presbyopia with an Optomechanical Model of the Human Eye

Thomas Forrister October 24, 2018

During routine exams, eye care professionals look for common refractive errors like nearsightedness, farsightedness, and astigmatism. As patients age, doctors also look for presbyopia, a loss of the accommodative amplitude that results long-term in a complete loss of the near vision. The visual accommodation process is complex, and useful eye properties needed to improve diagnosis and presbyopia treatment are difficult to obtain. To address the problem of measuring the refractive index of the lens, researchers developed a reverse engineering technique […]

Read More

Chandan Kumar September 5, 2018

To characterize hyperelastic materials, we need experimental data from a variety of tests, including subjection to uniaxial tension and compression, biaxial tension and compression, and torsion. Here, we show how to model the compression of a sphere made of an elastic foam using tension and compression test data obtained via uniaxial and equibiaxial tests. We demonstrate the use of the compressible Storakers hyperelastic material model for computation as well as how force-versus-stretch relationships are calculated for uniaxial and equibiaxial tests.

Read More

Brianne Costa May 11, 2018

Shape memory alloys (SMAs) are alloys with “memory”: They can return to their original shape after being deformed via a change in pressure or temperature. SMAs are used in a wide variety of applications — including metallurgy, manufacturing, biomedicine, and children’s arts and crafts — and their uses are always expanding…

Read More

Caty Fairclough February 13, 2018

To treat atherosclerosis, a cardiovascular disease in which a buildup of plaque causes an artery to narrow, doctors can insert a tiny wire mesh tube called a stent into the obstructed artery. Expanding the stent opens up the artery and helps restore blood flow. To successfully perform this operation and minimize potential health hazards, stent designs must be thoroughly studied and optimized. To do so, we can perform a nonlinear structural mechanics analysis with the COMSOL Multiphysics® software.

Read More

Guest Björn Fallqvist January 11, 2018

Today, guest blogger Björn Fallqvist of Lightness by Design, a COMSOL Certified Consultant, discusses using simulation to provide insight into the mechanical behavior of cells. Biological cells are essential for life as we know it. They not only store and replicate hereditary information in the form of DNA but also are instrumental in biological processes. In most, if not all, of these processes, the mechanical behavior of cells is a main factor in ensuring normal physiological functions.

Read More

Phillip Oberdorfer December 15, 2017

The physics behind filling a water balloon seem simple at first glance, but involve a rather complex interplay of fluid flow and a nonlinear hyperelastic material. Fortunately, it is easy to set up and solve this type of model in the COMSOL Multiphysics® software. Let’s see how…

Read More

Bridget Paulus November 6, 2017

Optimizing fuel for nuclear reactors can increase the amount of power they generate, improve their safety, and lower greenhouse gas emissions. However, studying nuclear fuel can be complex, as it involves interactions between multiple physical phenomena. In his keynote talk from the COMSOL Conference 2017 Boston, Andrew Prudil of Canadian Nuclear Laboratories (CNL) discussed using multiphysics models to gain insight into nuclear fuel. If you missed his presentation, find a video recording and summary below.

Read More

Mats Danielsson November 2, 2017

In structural mechanics, there may be situations when you want to implement your own material model. The COMSOL Multiphysics® software gives you the option to program your own material model in C code. The compiled code can then be called from the program using the External Material feature. Here, we demonstrate how to implement an external material model and then use it in an example analysis.

Read More

Bridget Cunningham June 12, 2017

In the last seven years, the output of the manufacturing industry has increased by a total of around 10–20%. This growth is partly thanks to technologies and processes that save on time and costs, such as 3D printing and, as is described here, powder compaction. To model this process, we can use the new porous plasticity models in the latest version of the COMSOL Multiphysics® software.

Read More

Mateusz Stec October 28, 2016

Imagine bending a metallic paper clip back and forth until, after a few repetitions, it breaks entirely. This is one example of fatigue failure, the most common type of structural collapse. In more severe cases, such failure can lead to collapse or malfunction in structures like car exhaust pipes and aircraft jet engines. To better understand and predict fatigue failure in elastoplastic materials, we can use the COMSOL Multiphysics® software to accurately model both the materials and the fatigue process.

Read More

Ed Gonzalez October 11, 2016

Many polymers and biological tissues exhibit viscoelastic deformation, which has a time-dependent response even if the loading is constant in time. Linear viscoelasticity, where the stress depends linearly on the strain and strain rate, is a common approximation. We usually assume that the viscous part of the deformation is incompressible, so the volumetric deformation is purely elastic. As of COMSOL Multiphysics® 5.2a, you can model large-strain viscoelasticity besides linear viscoelasticity. See how to use this material model in a biomedical […]

Read More


Categories


Tags

1 2