ESI Group (Germany)

The Modelica language is well suited to model systems with discrete and continuous dynamics. If one wants to model the flow of items through manufacturing steps such as preparation, mounting, or transport in the shop floor, this feature is crucial. The library ProcessSimulation can be used to model such processes. By default, it omits the technical details of the process steps, and focuses on the flow of material items through the process steps. In addition to that, a base model to calculate the energy consumption in the different manufacturing steps is provided. It can be enriched with technical details of the components. The library can be used for the calculation of (net) energy consumption, but also for task planning.

Co-simulation techniques have evolved significantly over the last 10 years. System simulation and hardware-in-the-loop testing are used to develop complex products in many industrial sectors. The Functional Mock-Up Interface (FMI) represents a standardized solution for integration of simulation models, tools and solvers. In practice the integration and coupling of heterogeneous systems still require enormous efforts. Until now no standardized interface or protocol specification is available, which allows the interaction of real-time and non-real-time systems of different vendors. This paper presents selected technical aspects of the novel Distributed Co-simulation Protocol (DCP) and highlights primary application possibilities. The DCP consists of a data model, a finite state machine, and a communication protocol including a set of protocol data units. It supports a master-slave architecture for simulation setup and control. The DCP was developed in context of the ACOSAR project and was subsequently adopted by Modelica Association as a Modelica Association Project (MAP). It may be used in numerous industrial and scientific applications. The standardization of the DCP allows for a modular and interoperable development between system providers and integrators. In the end, this will lead to more efficient product development and testing.

In this paper a new library for co-simulation of discrete element method and Modelica models is presented. For this a component-based approach is used that allows closed modeling and visualization of discrete element systems in a modelica tool. Translation into a native DEM description language and co-simulation is done by a separate compiler and backend. Usage and functionality are shown in a simple use case of a bucket excavator digging a hole.

In order to increase the powder bed production rates, the laser power and diameter are increased enabling faster scanning, thicker powder layers and wider hatches. These parameters however interact in a very complex manner: For example increasing the laser power may lead to significant evaporation of the molten metal. Increasing the scan speed may lead to reduced melting and lack of fusion of the powder particles. Combining higher scanning speeds with increased layer thickness enhances lack of fusion even more. Larger beam diameters reduce the energy density and hence impose limitations to scan speeds. Physics based modelling has the potenti al to shed light into how these competing phenomena interact and can accelerate fine tuning build parameters to achieve design goals. Models resolving the heat source powder interaction and describing the melt pool and solidification processes could not be formally validated using experimental data due to the extreme severity of the processing environment. In an effort to verify models describing melt pool behavior the results of two different algorithms are compared: Lattice Boltzmann and Finite Volume Computational Fluid Dynamics. Both codes were developed separately by two different and independent teams. A reference benchmark is defined with corresponding operation conditions. The physical assumptions are aligned as far as possible. The melt pool characteristics and the thermal cycles are compared.

Fibre reinforced plastics are widely used for energy absorbing parts. Due to their superior strength to density ratio they provide a high performance and are ideal for lightweight design for crashworthiness. For this, it is essential that the mechanical behaviour of fibre reinforced composites be predicted correctly by simulation. However, due to the complex inner structure, this is still a challenging task, in particular in case of highly nonlinear crash loading. In order to provide an alternative in this paper a virtual manufacturing simulation chain is proposed to gather detailed geometrical information about the roving structure of a filament wound tube on meso-scale. In addition effective material properties, based on calibrated models of the individual constituents, for the filament–matrix interaction are derived by micro-scale calculations. Both, combined with a USER MATERIAL model for the roving structure finally provide a complete finite element model which is used for the crash simulation of the filament wound tube. By comparing the numerical results to experimental data, the potential of the approach is shown and occurring differences are discussed as well as possible subsequent investigations are proposed.

This paper describes a complete CFD model of the laser metal deposition process. The model covers the complete process, starting from the simulation of powder particles in the deposition head and finishing with the final part. Individual phenomena that are considered in the gas-phase stage of the model include the ricocheting of particles within the head, the flow of powder particles, their interaction with the laser and powder catchment/bouncing. Phenomena considered in the liquid phase (melt pool) stage of the model include particle enthalpy effects, buoyancy, temperature-dependent material properties and Marangoni forces. The CFD model is coupled with a metallurgical database to predict the phase and material properties of the solidified deposit and heat affected area and residual stresses in the part. Modelled and experimental characteristics of multi-track deposits of M2 steel show good agreement.

Knowledge culture is one aspect in corporate culture. It describes, how knowledge is identified, acquired, developed, distributed, used and retained. There are tree levels with which the culture can be described: basic underlying assumptions, norms and values, artifacts. Based on this description it is possible to analyse the current culture and define measures to change it towards a more knowledge oriented culture. A survey on the wm03 had shown, that in most organization still exist an overlap or an ambivalence which is characterized by non-knowledge-oriented culture elements. For the change of culture the tools that are developed for cultural change must be adapted for the specific needs of knowledge cultural change.