Session Details

16:00
Error estimation approach for controlling the macro step-size for explicit co-simulation methods
Tobias Meyer (Technical University of Darmstadt), Jan Kraft (Technical University of Darmstadt), Pu Li (Technical University of Darmstadt), Daixing Lu (Technical University of Darmstadt), Bernhard Schweizer (Technical University of Darmstadt)

Kurzfassung:
An approach for controlling the macro-step size in connection with explicit co-simulation methods is suggested. The method is tailored for applied-force coupling techniques. Each macro-time step is carried out with two different explicit co-simulation methods. By comparing the variables of both results, an error estimator for the local error can be constructed. A step-size controller for the macro step-size can be implemented. Examples are presented demonstrating the applicability and accuracy.

16:20
Quasi-Newton methods for unstable partitioned fluid-structure interactions
Nadja Wirth (Fraunhofer Institute for Algorithms and Scientific Computing SCAI), Bettina Landvogt (scapos AG)

Kurzfassung:
The co-simulation software MpCCI offers various coupling algorithms for transient multiphysical applications. For fluid-structure interactions, where the density ratio between fluid and structure is almost 1, instabilities can occur. The presented Quasi-Newton relaxation considers the coupling as a fix point problem, which is solved by the Newton method using approximations of the Jacobian. It stabilizes the co-simulation and reduces the number of iterative coupling steps per time increment.

16:40
Design of a Nonlinear Observer for a Very Flexible Parallel Robot
Fatemeh Ansarieshlaghi (University of Stuttgart), Peter Eberhard (University of Stuttgart)

Kurzfassung:
A flexible robot in lambda configuration has been modeled and built in hardware. Since there is no direct feedback of the end-effector, a nonlinear observer to estimate the position of the end-effector is designed and implemented. The nonlinear observer results show that the end-effector position can be estimated with high accuracy. Also, using results from the nonlinear observer, the model of the robot is improved so that the maximum end-effector absolute tracking error is drastically decreased.

17:00
Shape optimization of wind turbine blades in a fluid structure interaction simulation
Shahrokh Shayegan (Technical University of Munich), Reza Najian Asl (Technical University of Munich), Roland Wüchner (Technical University of Munich), Kai-Uwe Bletzinger (Technical University of Munich)

Kurzfassung:
This contribution presents the shape optimization of wind turbine blades in the context of a fluid-structure interaction simulation.Vertex Morphing method,which is a node-based shape control technique, is used to find optimal design of the blades.Gradient-based optimization together with continuous adjoint based shape sensitivity analysis is employed to handle the large number of design variables.The fluid-structure interaction problem is solved using a partitioned, strong coupling algorithm.

17:20
Co-simulation in the vehicle development process
Stefan Steidel (Fraunhofer Institute for Industrial Mathematics ITWM), Michael Burger (Fraunhofer Institute for Industrial Mathematics ITWM)

Kurzfassung:
Modern vehicles are highly complex systems consisting of many subsystems in various physical domains that dynamically interact. In this context, co-simulation strategies are particularly attractive as each subsystem is solved via tailored simulation tools with appropriate numerical methods. Industrial applications induce enormous numerical challenges regarding efficiency, accuracy and stability. We present co-simulation strategies by means of selected application examples in vehicle engineering.

17:40
Co-Simulation of electro-mechanical systems for the development of circuit breakers
Thorsten Schindler (ABB Corporate Research Center Germany)

Kurzfassung:
This article describes and discusses the co-simulation methodology for the coupling of multiphysics problems in the field of switching development. Depending on the need and the questions to be answered different tools are applied at the ABB Corporate Research Center. Built-in co-simulation interfaces as well as a parallel co-simulation framework based on a general middleware with communication via TCP/IP are used. The latter has been developed in cooperation with the University of Darmstadt. The article discusses a linear actuator on the basis of the Thomson coil and a recloser.