GAMM2025

Session

S06.1: Material modelling with metals

S06.1

8 Apr 2025, 08:30

Lecture and Conference Centre

Conveners

S06.1: Material modelling with metals: S06.1.01

• Stanisław Stupkiewicz

S06.1: Material modelling with metals: S06.1.02

• Stanisław Stupkiewicz
• Björn Kiefer

S06.1: Material modelling with metals: S06.1.03

• Björn Kiefer

Description

The section focuses on constitutive modelling of natural and artificial materials subject to elastic and inelastic deformation processes. The aim is to compare new constitutive models formulated on both the phenomenological and the micromechanics basis to determine their validity by comparison of simulations with experiments. A wide range of open problems will be considered in the section, like multi-scale modelling of heterogeneous materials, implementation of constitutive models in numerical applications, and the virtual testing of structural systems.

139. A novel algorithm for crystal plasticity based on an augmented Lagrangian formulation

Alexander Niehüser

08/04/2025, 08:30

Crystal plasticity theory offers a powerful framework for analyzing plasticity at different scales while incorporating crystallographic information into the constitutive model. Unfortunately, classic rate-independent crystal plasticity models face long-standing problems regarding the determination of active slip systems and the computation of non-unique solutions. A very popular and already...

140. Analysis and comparison of interior-point methods for rate-independent single-crystal plasticity

Felix Steinmetz

08/04/2025, 08:50

Simulating the deformation behavior of crystals provides fundamental insights into the mechanics of polycrystalline materials like metals and alloys. Single-crystal plasticity models, based on the crystallographic structure of a single grain and formulated through multisurface plasticity, describe this behavior as an optimization problem governed by the principle of maximum plastic dissipation...

141. Numerical Investigation and Validation of a Riveted Connection with LPBF AlSi10Mg Components based on a Thermomechanical Coupled Chaboche-GTN Approach

Lukas Richter

08/04/2025, 09:10

Additive manufactured materials enable new possibilities in the construction of components by realizing complex geometries. One example of such materials is the aluminum alloy AlSi10Mg, that is manufactured by powder-based laser fusion and demonstrates a mechanical behavior comparable to conventionally processed materials. The manufacturing process results in an inhomogeneous structure that is...

142. A novel procedure for identification of material parameters in advanced creep-fatigue constitutive model based on artificial neural networks

Alexander Jahnke

08/04/2025, 09:30

Mechanism-based constitutive models for creep-fatigue analysis and the corresponding user material subroutines for finite element codes were developed for years by many research groups. However, the application of such models in the industry is limited by the availability of accurate experimental data and the time-consuming parameter identification.

The presentation focuses on the...

143. Hybrid data-driven and physics-informed regularized learning of cyclic plasticity with neural networks

Stefan Hildebrand

08/04/2025, 09:50

Machine Learning (ML) methods have proven their potential in material modeling with the goal to replace analytical constitutive models by machine-learned relationships [1]. Apart from the possible simplification of existing approaches, the application of ML is motivated by the goal to accurately characterize materials by a quick and integrated, automatized process [2]. The present talk...

144. On Unifying Tensor and Matrix Approaches in Material Modeling

Rainer Schlebusch

08/04/2025, 10:10

This contribution examines the unification of tensor and matrix approaches in continuum mechanics, with a particular emphasis on their relationships and the potential for smooth interchange between the two frameworks. While tensor algebra provides a coordinate-independent framework, matrix algebra offers a computationally accessible representation. The tensor and matrix representations are...

145. Stress partitioning in thermoelastoplastic materials

Nikola Lalović

08/04/2025, 16:30

This presentation introduces a thermodynamically consistent formulation for the heat source arising from plastic deformation within a small deformation framework (cf., [1,2]), which leads to an additive decomposition of the flow stress into two distinct parts: one associated with dissipation and another linked to the energy stored within the material due to microstructural changes, such as...

146. Different aspects of modelling propagative instabilities in aluminum

Marzena Mucha

08/04/2025, 16:50

The Portevin-Le Chatelier (PLC) effect is a propagative instability phenomenon appearing in metals, for example in steel and aluminum alloys at elevated and room temperature, respectively. It is characterized by serrations (repetitive changes from hardening to softening) visible in load-displacement diagrams and by traveling strain rate bands that can be observed in the sample. At the atomic...

147. On The Blow-Up Solutions In Nonlinear Elasticity Theory

Jerzy Gawinecki

08/04/2025, 17:10

We consider the initial value problem for nonlinear partial differential equations describing the motion of an inhomogeneous and anisotropic hyperelastic medium. We assume that the stored energy function of the hyperelastic material is a function of the point x and the nonlinear Green-St. Venant strain tensor e_jk. Moreover we assume that the stored energy function is C^∞ with respect to x and...

148. Smoothed Particle Hydrodynamics Modeling of Solid-state Deposition Process Friction Surfacing

Ahmed Elbossily

08/04/2025, 17:30

In this study, the smoothed particle hydrodynamics (SPH) method is used for modeling and simulating the solid-state deposition process, friction surfacing (FS), involving severe plastic deformation at elevated temperatures. To address the high computational cost of SPH, a GPU-based framework was developed with additional enhancement techniques such as particle switching and subdomain...

149. 1D model of twin branching in shape memory alloys accounting for the energy dissipation effects

Stanisław Stupkiewicz

09/04/2025, 08:30

In shape memory alloys, the competition between interfacial and elastic strain energy contributions leads to twin branching, i.e., to refinement of the twin laminates close to the macroscopic interface between twinned martensite and austenite. We have developed a 1D model of twin branching in which the average twin spacing is a continuous function of the distance from the austenite-twinned...

150. Evaluating chemo-mechanical coupling in phase-field methods: Benchmarks and Insights

Thea Kannenberg

09/04/2025, 08:50

Multiphase-field models allow for the simulation of microstructural evolution and phase transformations in materials, eliminating the necessity for computationally expensive interface tracking. Furthermore, multiphase-field methods facilitate the integration of various driving forces, e.g., chemical and mechanical driving forces, within a unified framework. The multiphase-field method provides...

151. Multiphase-Field Modeling of Microstructure Evolution during Solid-State Processing of Al Alloys

H.A.T. Vimukthi Nanayakkara

09/04/2025, 09:10

Solid-state processing techniques like friction extrusion (FE), friction stir welding (FSW), and friction surfacing (FS), represent advanced methods for processing Al alloys. These techniques utilize frictional heat and intense mechanical deformation to induce microstructural evolution without reaching the melting point. This study focuses on Al-Cu-Li alloys, which are widely employed in the...

152. New insights into grain boundary kinetics by phase-field crystal modeling

Maik Punke

09/04/2025, 09:30

The so-called phase-field crystal (PFC) model [1, 2] emerged as a prominent approach to describe crystal structures at large (diffusive) timescales through a continuous, periodic order parameter representing the atomic density. It reproduces the main phenomenology for crystalline systems, including solidification and crystal growth, capillarity, lattice deformations as well as nucleation and...

153. Numerical Modelling of Deformation-Induced Martensitic Transformation in Additively Manufactured 316L Stainless Steel under Cryogenic Conditions

Philipp Maasch

09/04/2025, 09:50

Cryogenic structural components, including collars, bladders, and keys for superconducting magnets, as well as elements for liquid hydrogen storage systems, are often fabricated from austenitic stainless steel (e.g., 316L) due to favorable mechanical properties and corrosion resistance. However, producing these complex geometries through traditional methods is challenging. Additive...