Language-Driven Engineering An Interdisciplinary Software Development Paradigm

We illustrate how purpose-specific, graphical modeling enables application experts with different levels of expertise to collaboratively design and then produce complex applications using their individual, purpose-specific modeling language. Our illustration includes seven graphical Integrated Modeling Environments (IMEs) that support full code generation, as well as four browser-based applications that were modeled and then fully automatically generated and produced using DIME, our most complex graphical IME. While the seven IMEs were chosen to illustrate the types of languages we support with our Language-Driven Engineering (LDE) approach, the four DIME products were chosen to give an impression of the power of our LDE-generated IMEs. In fact, Equinocs, Springer Nature's future editorial system for proceedings, is also being fully automatically generated and then deployed at their Dordrecht site using a deployment pipeline generated with Rig, one of the IMEs presented. Our technology is open source and the products presented are currently in use.Comment: 43 pages, 30 figure

Massively parallel multiphase field simulations

Die Multiphasenfeldmethode ist ein häufig genutztes Simulationswerkzeug für die Mikrostrukturevolution. Eine hohe Anzahl verschiedener Phasenfelder, die Körner verschiedener Phasen und Orientierungen beschreiben, führt zu signifikanten Anforderungen an Speicher und Rechenleistung. Eine Hybrid-Parallelisierung, die MPI und OpenMP vereint, wird vorgestellt und zwei verschiedene Lastbalancierungsverfahren werden vorgestellt und verglichen. Es werden Ergebnisse für Leistungstest und eine Reihe von Anwendungen gezeigt, darunter Kornwachstum in polykristallinen Werkstoffen mit hunderttausenden verschiedenen Phasenfelder sowie die Erstarrung einer Magnesium-Aluminium Legierung. Zudem wird eine Anwendung der Multiphasenmethode zur Konstruktion von Mikrostrukturen mit einer vorgegebenen Korngrößenverteilung präsentiert.The multiphase field method is a commonly used tool to simulate the evolution of microstructure during materials processing. Even when using a concept called active parameter tracking, which substantially reduces the computational complexity, the resource demands of the multiphase field method remain significant in both time and memory. A hybrid-parallelization is presented and two different load-balancing schemes are described and compared. Results are presented for performance benchmarks as well as for a variety of applications, including grain growth in polycrystalline materials with hundreds of thousands of different phase fields and Mg-Al alloy solidification. In addition a way of utilizing the multiphase field method is shown that allows the construction of microstructures with a given grain size distribution

Numerical Study of Epitaxial Growth after Partial Remelting during Selective Electron Beam Melting in the Context of Ni–Al

In the selective electron beam melting approach an electron beam is used to partially melt the material powder. Based on the local high energy input, the solidification conditions and likewise the microstructures strongly deviate from conventional investment casting processes. The repeated energy input into the material during processing leads to the partial remelting of the already existing microstructure. To closer investigative this effect of partial remelting, in the present work the phase-field model is applied. In the first part the solidification of the referenced Ni–Al system is simulated in respect to selective electron beam melting. The model is calibrated such to reproduce the solidification kinetics of the superalloy CMSX-4. By comparison to experimental observations reported in the literature, the model is validated and is subsequently applied to study the effect of partial remelting. In the numerical approach the microstructures obtained from the solidification simulations are taken as starting condition. By systematically varying the temperature of the liquid built layer, the effect of remelting on the existing microstructure can be investigated. Based on these results, the experimental processing can be optimized further to produce parts with significantly more homogenous element distributions

Numerical study of epitaxial growth after partial remelting during selective electron beam melting in the context of Ni–Al

In the selective electron beam melting approach an electron beam is used to partially melt the material powder. Based on the local high energy input, the solidification conditions and likewise the microstructures strongly deviate from conventional investment casting processes. The repeated energy input into the material during processing leads to the partial remelting of the already existing microstructure. To closer investigative this effect of partial remelting, in the present work the phase-field model is applied. In the first part the solidification of the referenced Ni–Al system is simulated in respect to selective electron beam melting. The model is calibrated such to reproduce the solidification kinetics of the superalloy CMSX-4. By comparison to experimental observations reported in the literature, the model is validated and is subsequently applied to study the effect of partial remelting. In the numerical approach the microstructures obtained from the solidification simulations are taken as starting condition. By systematically varying the temperature of the liquid built layer, the effect of remelting on the existing microstructure can be investigated. Based on these results, the experimental processing can be optimized further to produce parts with significantly more homogenous element distributions

Parallel multiphase field simulations with OpenPhase

The open-source software project OpenPhase allows the three-dimensional simulation of microstructural evolution using the multiphase field method.The core modules of OpenPhase and their implementation as well as their parallelization for a distributed-memory setting are presented. Especially communication and load-balancing strategies are discussed. Synchronization points are avoided by an increased halo-size, i.e. additional layers of ghost cells, which allow multiple stencil operations without data exchange. Load-balancing is considered via graph-partitioning and sub-domain decomposition. Results are presented for performance benchmarks as well as fora variety of applications, e.g. grain growth in polycrystalline materials, including a large number of phase fields as well as Mg-Al alloy solidification

Full-field simulation of solidification and forming of polycrystals

The phase-field method has emerged as the method of choice for simulation of microstructure evolution and phase-transformations in material science. It has wide applications in solidification and solid state transformations in general. Recently, the method has been generalized to treat large deformation and damage in solids. A through process full-field simulation will be presented starting from solidification and ending with the evolution of damage during large deformation. Aspects of numerical discretization, efficient numerical integration and massive parallelization will be discussed

Full-field simulation of solidification and forming of polycrystals

The phase-field method has emerged as the method of choice for simulation of microstructure evolution and phase-transformations in material science. It has wide applications in solidification and solid state transformations in general. Recently, the method has been generalized to treat large deformation and damage in solids. A through process full-field simulation will be presented starting from solidification and ending with the evolution of damage during large deformation. Aspects of numerical discretization, efficient numerical integration and massive parallelization will be discussed

Computationally Efficient Phase-field Simulation Studies Using RVE Sampling and Statistical Analysis

International audienceFor large-scale phase-field simulations, the trade-off between accuracy and computational cost as a function of the size and number of simulations was studied. For this purpose, a large reference representative volume element (RVE) was incrementally subdivided into smaller solitary samples. We have considered diffusion-controlled growth and early ripening of δ′δ′ (Al3Li) precipitate in a model Al-Li system. The results of the simulations show that decomposition of reference RVE can be a valuable computational technique to accelerate simulations without a substantial loss of accuracy. In the current case study, the precipitate number density was found to be the key controlling parameter. For a pre-set accuracy, it turned out that large-scale simulations of the reference RVE can be replaced by simulating a combination of smaller solitary samples. This shortens the required simulation time and improves the memory usage of the simulation considerably, and thus substantially increases the efficiency of massive parallel computation for phase-field applications