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Laser beam welding is a metal fusion technique that, with its high advance speed and low thermal distortion, is used more frequently nowadays in industry. During welding, the solidification front is located in the so‐called mushy zone, which forms the transition region between the completely solidified and mixture zone of solid and fluid material behind the laser beam. In this zone, various process...
In the present work, a mixed least‐squares finite element method (LSFEM) is used, which is applied on the partial differential equations arising from the Theory of Porous Media (TPM), see for example [1, 2, 3]. Since the LSFEM is not limited to the LBB condition, the method has some theoretical advantages over the well‐known (mixed) Galerkin method, see [4]. In particular, the LSFEM leads to positive...
For modeling materials with size‐effects, the classical Cauchy linear elasticity theory and first‐order homogenization procedures are insufficient. Enriched continua are able to capture such phenomena in principle. In this work, we model the size‐effects of metamaterial beams via the relaxed micromorphic continuum. The material parameters of the relaxed micromorphic model are evaluated. We present...
This work presents a multi‐phase approach to model freezing processes within a coupled finite element formulation using the Theory of Porous Media (TPM), see also [1]. The focus of the study is to enhance the numerical stability for the volume fraction ice as is it highly sensitive to phase discontinuities. To address this issue, a discontinuous approximation is employed for the volume fraction ice...
Current research focuses on the induction of residual stresses in a component during its manufacturing process, which shows a significant impact on the final component's properties. During the manufacturing of a hot bulk forming component, the temperature evolution allows to influence the resulting residual stress state efficiently and purposefully. Following the characterization of residual stresses...
In this paper, we propose an efficient numerical scheme for the prediction of the magnetic stray fields in two‐dimensional random microheterogeneous materials. Since data‐driven models require thousands of training datasets, Finite Element Method simulations appear to be too time consuming. Therefore, a stochastic model based on Brownian motion, which uses an efficient evaluation of stochastic transition...
The influence of different fiber contents and orientations on the overall material behavior of steel microfiber reinforced UHPC is studied. To analyze the failure behavior of UHPC, the three‐point bending beam tests at low cycle is investigated experimentally and simulated numerically. For that purpose, recently developed phenomenological material model, see our recent works [1] and [2], based on...
This work shows an adaptive Model Order Reduction (MOR) scheme for the computation of unit cells with non‐linear material behavior. A reduction of dimensionality and computational cost is achieved by projecting the high‐fidelity system of equations (SOE) from the full vector space to a lower dimensional subspace. An adaptive algorithm updates the projection operator, which is initially gained from...
The striving for the independence of fossil energy sources by further development of renewable energies as well as the change in mobility act as a driving force on technological innovations. Magnetic materials with improved magnetic efficiency help to push the limits for optimized, low‐loss power conversion applications and electrification. Besides improving the chemical composition, that is, gaining...
This paper tries to simulate a hydraulic failure by using a ternary, saturated, quasi‐static Theory of Porous Media (TPM) model. The concept of a hydraulic failure is shortly explained and the derivation of the TPM setup including the limitation of the volume fractions is depicted. A schematic excavation with a sheet piling is used to test the created model and prove the general feasibility of the idea.
Laser beam welding is a contact free fusion technique which has gained importance during the last years due to rising need for automatization in industrial processes. However, a well‐known problem is the formation of solidification cracks in the rear region of the melting pool. In order to investigate the formation of solidification cracks which is highly dependent on the chemical composition, the...