Interfaces

The basic version of the simulation software alaska/ModellerStudio already contains interfaces for coupling externally defined functionality. Additional alaska add-ons provide interfaces to other CAE software products.

The alaska/ModellerStudio provides a variety of built-in functions. These are for example mathematical functions like sin(), cos() and fabs(), functions for describing the behavior of model parameter values, e.g. step(), bump() and bistop () as well as functions for using externally provided data (characteristic curve/characteristic map interpolation).

In addition, the alaska/ModellerStudio offers the user the possibility to define his own user functions. These functions can be used in simulation models in compiled form analogous to the predefined functions.

Any externally defined functionalities can be coupled via a general DLL interface. These model components can depend on alaska model states and contain their own internal state variables. The data exchange with the alaska model takes place via input and output vectors at discrete points in time according to a specified step size. Unlike the generally readable alaska model descriptions, non-public know-how can be used in simulation models via this interface.

The coupling of alaska simulation models with MATLAB Simulink can be done in three different ways: 

• A special S-Function block in MATLAB Simulink loads the alaska calculation kernel and the alaska simulation model. The complete model is simulated using the MATLAB solver. Optionally, the results are also available in alaska for post-processing.
• Coupling of alaska/ModellerStudio with MATLAB Simulink or the alaska model with the Simulink model via a TCP/IP connection and a connection server. Both programs can run on different computers. Both models are solved with the solver of the respective software.
• Export of the Simulink model with the Simulink Coder and coupling to the alaska model via the general interface for externally defined functionality.

FE models of components that are available in the ANSYS software are reduced modally with ANSYS functionality. This means that the degree of freedom of the calculation model is drastically reduced. The special interface program Ansys2alaska processes the reduced model data and generates alaska simulation model components, which can be coupled directly with other alaska model components and used in common simulation models.

The use of CAD data in alaska simulation models can be done in different ways:

• Export of CAD volumes in *.stl format. This interface is universal because all CAD programs export data in this format. The mass properties are calculated on the basis of the exported data and a uniform density. In addition, a geometric representation is generated.
• If the CAD tool provides a suitable interface (e.g. Python) and can be used to access the internal data structures of the CAD tool, alaska part models can be generated directly. A conversion for CAD models in step format via the Python interface in FreeCAD serves as a template.

The bearing calculation module of the Mesys software (https://www.mesys.ch/) can be coupled to realistically represent rolling bearing forces in alaska simulation models. The description of the bearings is done in Mesys. The created bearing description file is referenced via a special alaska modeling element (template) and is used in the simulation to parameterize the bearing forces to be calculated in the Mesys DLL.

The simulation software alaska/ModellerStudio offers the possibility to connect external model components that comply with the FMI specification (Functional Mockup Interface), so-called FMUs (Functional Mockup Units).

In addition, the C++ class library alaska/SimulationEngine can be used to create custom FMUs for coupling with other (co-) simulation environments. (for more information: https://fmi-standard.org)