Inst. Werkzeugmaschinen und Fabrikbetrieb

255 Items

Recent Submissions
Hybrid Artificial Intelligence System for the Design of Highly-Automated Production Systems

Hagemann, Simon ; Sünnetcioglu, Atakan ; Stark, Rainer (2019-01-25)

The automated design of production systems is a young field of research which has not been widely explored by industry nor research in recent decades. Currently, the effort spent in production system design is increasing significantly in automotive industry due to the number of product variants and product complexity. Intelligent methods can support engineers in repetitive tasks and give them m...

Finite element analysis of in-situ distortion and bulging for an arbitrarily curved additive manufacturing directed energy deposition geometry

Biegler, Max ; Marko, Angelina ; Graf, Benjamin ; Rethmeier, Michael (2018-10-05)

With the recent rise in the demand for additive manufacturing (AM), the need for reliable simulation tools to support experimental efforts grows steadily. Computational welding mechanics approaches can simulate the AM processes but are generally not validated for AM-specific effects originating from multiple heating and cooling cycles. To increase confidence in the outcomes and to use numerical...

Investigation of liquid metal embrittlement of dual phase steel joints by electro-thermomechanical spot-welding simulation

Frei, Julian ; Biegler, Max ; Rethmeier, Michael ; Böhne, Christoph ; Meschut, Gerson (2019-02-22)

A 3D electro-thermomechanical model is established in order to investigate liquid metal embrittlement. After calibration to a dual phase steel of the 1000 MPa tensile strength class, it is used to analyse the thermo-mechanical system of an experimental procedure to enforce liquid metal embrittlement during resistance spot welding. In this procedure, a tensile stress level is applied to zinc coa...

Sensitivity analysis of the residual stress state in friction stir welding of high strength aluminum alloy

Bachmann, Marcel ; Rethmeier, Michael ; Wu, Chuan Song (2016-01)

In this paper, the friction stir welding process was numerically investigated for 6 mm thick aluminum alloy AA2024-T3. The finite element software COMSOL Multiphysics was used to calculate the transient thermal field during welding and the mechanical reaction depending on different mechanical clamping conditions and hardening models subsequently. A thermal pseudo-mechanical (TPM) heat source wa...

Numerical assessment and experimental verification of the influence of the Hartmann effect in laser beam welding processes by steady magnetic fields

Bachmann, Marcel ; Avilov, Vjaceslav ; Gumenyuk, Andrey ; Rethmeier, Michael (2015-11-18)

Controlling the dynamics in the weld pool is a highly demanding challenge in deep-penetration laser beam welding with modern high power laser systems in the multi kilowatt range. An approach to insert braking forces in the melt which is successfully used in large-scaled industrial applications like casting is the so-called Hartmann effect due to externally applied magnetic fields. Therefore, th...

Experimental and numerical assessment of weld pool behavior and final microstructure in wire feed laser beam welding with electromagnetic stirring

Meng, Xiangmeng ; Bachmann, Marcel ; Artinov, Antoni ; Rethmeier, Michael (2019-07-25)

Advantages such as element homogenization and grain refinement can be realized by introducing electromagnetic stirring into laser beam welding. However, the involved weld pool behavior and its direct role on determining the final microstructure have not been revealed quantitatively. In this paper, a 3D transient heat transfer and fluid flow model coupled with element transport and magnetic indu...

Assessment of thermal cycles by combining thermo-fluid dynamics and heat conduction in keyhole mode welding processes

Artinov, Antoni ; Karkhin, Victor ; Khomich, Pavel ; Bachmann, Marcel ; Rethmeier, Michael (2019-07-07)

A numerical framework for simulation of the steady-state thermal behaviour in keyhole mode welding has been developed. It is based on the equivalent heat source concept and consists of two parts: computational thermo-fluid dynamics and heat conduction. The solution of the thermo-fluid dynamics problem by the finite element method for a bounded domain results in a weld pool interface geometry be...

Numerical and experimental investigation of thermo-fluid flow and element transport in electromagnetic stirring enhanced wire feed laser beam welding

Meng, Xiangmeng ; Artinov, Antoni ; Bachmann, Marcel ; Rethmeier, Michael (2019-09-06)

The introduction of electromagnetic stirring to laser beam welding can bring several beneficial effects e.g. element homogenization and grain refinement. However, the underlying physics has not been fully explored due to the absence of quantitative data of heat and mass transfer in the molten pool. In this paper, the influence of electromagnetic stirring on the thermo-fluid flow and element tra...

Avoidance of liquid metal embrittlement during resistance spot welding by heat input dependent hold time adaption

Böhne, Christoph ; Meschut, Gerson ; Biegler, Max ; Rethmeier, Michael (2020-07-20)

Liquid metal embrittlement (LME) cracking can occur during resistance spot welding (RSW) in zinc-coated advanced high-strength steels (AHSS) for automotive production. In this study, a methodological variation of hold time is performed to investigate the process-related crack influence factors. A combination of numerical and experimental investigations confirms, that the extent of heat dissipat...

Kinematische Modellierung eines kontinuierlichen z-Faltprozesses für die Batterieproduktion

Glodde, Arne (2020)

Der immer weiter steigende Bedarf an Batteriezellen wird sich zukünftig kaum durch die konventionellen Verfahren decken lassen. Selbst innovative Verfahren im Forschungsstadium können die erforderliche Anlagengeschwindigkeit von einer Sekunde pro Falte nicht erreichen. Diese Lücke aufgreifend wurde ein kontinuierliches Verfahren entwickelt, welches großformatige z-gefaltete Elektroden-Separator...

SW-Code_II for semantic data linking

Fresemann, Carina (2020-07-20)

This software code supports engineeres linking produkt data to order giving struktures. The here given example uses product data, such as CAD oder Simulation Files and relates it to functional structures, modular kits, etc. The applied software is rule-based and support the analysis of the data content as well.

SW-Code_I for semantic data linking

Fresemann, Carina (2020-07-20)

This software supports engineers when allocating product data to structures or concepts. The here engaged used case refers to product data sheets, describing a product or a part of it, as well as export controll regulations, that have to be met. The software uses semantic technologies mainly from the area of NLP combined with rule based methods.

SW-Code for plausible GeometricData

Fresemann, Carina (2020-07-03)

Software Code, describing a routine for analysing geometric data in STEP File Format. The Code is intended to support engineers in the frame of variant management in PDM systems. These currently lack mechanisms for automatically check data for their compatibility to each other. This algorithm provides a solution for geometric data within one variant.

Statistical check of meta data

Fresemann, Carina (2020-07-13)

The SW Code searches within a variant, if meta data match each other. The Code has been written with the intention to support engineers by automatically verifying meta data. The Code learns via a KNN algorithms about historical variant descriptions. It reveals not plausible data without human interaction.

Chat Bot for variant management

Fresemann, Carina (2020-06-15)

The SW code describes a Chat Bot, that allows a user to store product data in relation to variants in a PDM System or other data base. It is intended to support engineers by delivering variant information from a CAD environment towards PDM System using natural language. Applying NLP releases the engineer from knowing variant codes and changing the system.

Lamé curve approximation for the assessment of the 3D temperature distribution in keyhole mode welding processes

Artinov, Antoni ; Karkhin, Victor ; Bakir, Nasim ; Meng, Xiangmeng ; Bachmann, Marcel ; Gumenyuk, Andrey ; Rethmeier, Michael (2020-05-04)

A novel approach for the reconstruction of an equivalent volumetric heat source from a known weld pool shape is proposed. It is based on previously obtained weld pool geometries from a steady-state thermo-fluid dynamics simulation. Hereby, the weld pool dimensions are obtained under consideration of the most crucial physical phenomena, such as phase transformations, thermo-capillary convection,...

Theoretical study of influence of electromagnetic stirring on transport phenomena in wire feed laser beam welding

Meng, Xiangmeng ; Artinov, Antoni ; Bachmann, Marcel ; Rethmeier, Michael (2020-04-29)

The additional element from the filler wire in the laser beam welding is usually distributed inhomogeneously in the final weld due to the high solidification rate of weld pool. It has been found that the electromagnetic stirring produced by an external oscillating magnetic field can enhance the material mixing in the weld pool to achieve a more uniform element distribution. However, the magneti...

Mathematical modeling of the geometrical differences between the weld end crater and the steady-state weld pool

Artinov, Antoni ; Karkhin, Victor ; Bachmann, Marcel ; Rethmeier, Michael (2020-04-28)

The geometrical characteristics of the weld end crater are commonly used as a means of validating numerical results in welding simulations. In this paper, an analytical model is developed for calculating the cooling stage of the welding process after the moving energy source is turned off. Solutions for various combinations of heat sources and heated bodies are found. It is shown that after tur...

Influence of welding parameters on electromagnetic supported degassing of die-casted and wrought aluminum

Fritzsche, André ; Hilgenberg, Kai ; Rethmeier, Michael (2020-04-29)

Laser beam welding of aluminum die casting is challenging. A large quantity of gases (in particular, hydrogen) is absorbed by aluminum during the die-cast manufacturing process and is contained in the base material in solved or bound form. After remelting by the laser, the gases are released and are present in the melt as pores. Many of these metallurgic pores remain in the weld seam as a resul...

Full penetration laser beam welding of thick duplex steel plates with electromagnetic weld pool support

Avilov, Vjaceslav ; Fritzsche, André ; Bachmann, Marcel ; Gumenyuk, Andrey ; Rethmeier, Michael (2016-03-31)

Full penetration high power bead-on-plate laser beam welding tests of up to 20 mm thick 2205 duplex steel plates were performed in PA position. A contactless inductive electromagnetic (EM) weld pool support system was used to prevent gravity drop-out of the melt. Welding experiments with 15 mm thick plates were carried out using IPG fiber laser YLR 20000 and Yb:YAG thin disk laser TruDisk 16002...