Structural Mechanics Module
New App: Beam Subjected to Traveling Load
In this application, the response to a set of load pulses traveling along a beam placed on equidistant supports is computed. The beam geometry, the speed and width of the load pulses, and their spacing can be varied.
An app of a beam subjected to load pulses traveling along it where the beam geometry, the speed and width of the load pulses, and their spacing can be varied.
Part Libraries for Structural Mechanics
In the new Part Libraries, a number of geometries have been added. There are two main groups: 2D beam cross sections and 3D models of bolts, nuts, and washers.
The beam cross sections come in two main categories: generic sections and standard sections. With a generic section, you have a parametrized representation of some common beam sections. When using the standard cross sections, which are available for U.S. and European standards, you can create the cross section with one to three parameters. As an example, for an HEA beam, you can enter values like 100, 120, 140, etc. to generate the beam geometry.
The main use for the beam cross sections is within the Beam Cross Section interface, but they can also be extruded to full 3D models.
In the Bolts folder, you can find bolts, nuts, and washers with different levels of detail ready for insertion in the model. The geometries are designed for easy meshing and the bolts are prepared for use together with the Bolt Pre-Tension feature in the Solid Mechanics interface.
When a bolt has been inserted from the Part Libraries, in the Prestressed Bolts in a Tube Connection model, the different geometric parameters can be easily defined.
A new feature, External Stress, has been introduced to the Linear Elastic Material, the Nonlinear Elastic Material, and the Hyperelastic Material subnodes. It is used for adding an extra stress contribution to the stress computed by the constitutive model.
- You can choose to only use the external stress as a load contribution and not add it to the stress tensor. This is typically the case when there is a pore pressure in a porous elastic medium.
- Stress tensors computed by other interfaces are available and can be selected.
- A pore pressure computed through the Darcy's law interface can be directly selected.
- There can be several external stress contributions to the same domain.
Multiphysics Coupling for Hygroscopic Swelling
When Solid Mechanics is combined with one of the Transport of Diluted Species or Transport of Diluted Species in Porous Media interfaces, a new multiphysics coupling called Hygroscopic Swelling is created. It has the same settings as the Hygroscopic Swelling subnode to the material model nodes. With this new multiphysics coupling, you are able to transfer a concentration of moisture, computed in the Transport of Diluted Species or Transport of Diluted Species in Porous Media interfaces, into a hygroscopic swelling strain.
Moisture concentration and deformations in a MEMS pressure sensor due to hygroscopic swelling.
Computation of Mass Properties
The structural mechanics physics interfaces (Solid Mechanics, Membrane, Shell, Plate, Truss, Beam, and Multibody Dynamics) can now return complete mass properties to the Mass properties node under Definitions. All types of mass contributions from the physics interfaces are accounted for:
- Mass density in all material models.
- Added mass.
- Point mass and inertia.
- Mass and inertia on Rigid domains and Rigid connectors.
- Inertia with respect to thickness in beams and shells.
- Inertia with respect to rotation around the axis of a beam.
Spring Material Model in the Truss Interface
A new material model, intended for simplifying the modeling of discrete springs and dampers, has been added to the Truss interface. The spring is connected between two points that can have arbitrarily large deformations. The purpose is not primarily to use the spring in truss models, but to use it for connecting points in other structural mechanics interfaces. The spring can be placed in parallel with a viscous damper and also have loss factor damping. The spring characteristics can be nonlinear and it is possible to activate and deactivate it based on a general logical expression.
Physics-Based Mesh in the Truss interface
The default mesh for the Truss interface now uses one element per edge. This resolution is sufficient for all truss structures, so it is only when modeling cables that more elements are actually required. The advantage with this is that the default mesh will be much smaller than before. Also, the default discretization in the Truss interface is now to use linear shape functions, rather than quadratic.
In the Solid Mechanics and Membrane interfaces, it is now possible to specify Viscous damping together with the Linear Elastic Material. Viscous damping, which relates the stress to the strain rate, can be used both in the time and frequency domains.
Viscoelasticity Added to the Membrane Interface
In the Membrane interface the effects of viscoelasticity have now been included with the following viscoelastic models available:
- Generalized Maxwell
- Standard Linear Solid