MEMS Module Updates

For users of the MEMS Module, COMSOL Multiphysics® version 5.3 includes extended Spring Foundation functionality, energy quantity variables for contact modeling, and enhanced external material functionalities. See all of the new features and functionality in the MEMS Module below.

Energy Quantity Variables for Modeling Contact

New variables containing energy quantities are available when modeling contact. You can now obtain the energy dissipated by friction as well as the elastic energy stored in the contact penalty factors. This is useful for checking energy balances as well as a posteriori checks on selected penalty factors.

A COMSOL Multiphysics plot depicting the energy balance for a rolling and sliding cylinder. Energy balance for a cylinder rolling and sliding inside a channel due to gravity. Energy balance for a cylinder rolling and sliding inside a channel due to gravity.

Application Library path for an example containing new variables for energy quantities when modeling contact:

Structural_Mechanics_Module/Contact_and_Friction/transient_rolling_contact

Elastic Layers Described by Material Data

You can now prescribe the elastic properties of a spring foundation or a thin elastic layer with material data such as Young's modulus and Poisson's ratio together with a given thickness of the layer. This simplifies, for example, the modeling of adhesive layers with known material properties. When using the material data and thickness as input, the strains in the elastic layer are also available as results.

Spring Boundary Conditions for Rigid Domain and Rigid Connector

The Rigid Connector and Rigid Domain features in all physics interfaces have been augmented with a spring boundary condition called Spring Foundation. It has the following properties:

  • The spring can be attached at an arbitrary position
  • Both translational and rotational springs are available
  • The spring can have loss factor damping
  • The spring can act in parallel with viscous damping (for both translation and rotation)

Frequency-Domain Analysis with Contact

You can study the frequency response of a structure where a contact state has been computed in a previous study. As an example, you can perform frequency-domain analyses of bolted structures and study the influence of contact states on the dynamic properties.

Harmonic Perturbation for Prescribed Velocity and Acceleration

In the Shell, Plate, and Beam interfaces, you can provide values for harmonic perturbation for the Prescribed Velocity and Prescribed Acceleration nodes.

Enhancements to Including External Material Functionalities

Several enhancements have been made with regards to the power and usability of material models created with user-defined C code:

  • Inelastic strain contributions for nonlinear elastic and hyperelastic materials can now be implemented
  • Two new interfaces to the C code that take several more quantities as input, including deformation gradients
  • Now possible to include serendipity shape functions
  • Small strain formulation has been added
  • You can start by making a special initialization call to the user function
  • You can make a cleanup call to the user function (e.g., closing files)
  • The state variables can be named individually
  • Time is available as an input argument