The Johnson–Cook constitutive equation is very widely used for simulating cutting processes. Different methods are applied for establishing parameters of the constitutive equation. Based on the methods analysed in this study, two algorithms were worked out to determine the constitutive parameters for the prevailing conditions during cutting processes. In the first algorithm, all constitutive parameters were established simultaneously with standardized test methods. In the second algorithm, the constitutive parameters were established separately in accordance with the cutting conditions prevailing in machining processes. The developed methodology was verified with AISI 1045 heat-treatable steel and Ti10V2Fe3Al (Ti-1023) titanium alloy. The two materials were examined in standardized tensile and compression tests with varying strain rates and temperatures. In addition, the kinetic characteristics of the orthogonal cutting process were established. Based on the results obtained by experiment and the algorithms developed, the constitutive parameters for the cutting conditions were calculated. The parameters were used to determine the material model for simulating the orthogonal cutting process. The algorithms developed were verified by comparing the simulated and experimentally determined kinetic cutting characteristics, which confirmed their good quality.

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This paper describes the interdependence of additive and subtractive manufacturing processes using the production of test components made from S Al 5356. To achieve the best possible part accuracy and a preferably small wall thickness already within the additive process, a closed loop process control was developed and applied. Subsequent machining processes were nonetheless required to give the components their final shape, but the amount of material in need of removal was minimised. The effort of minimising material removal strongly depended on the initial state of the component (wall thickness, wall thickness constancy, microstructure of the material and others) which was determined by the additive process. For this reason, knowledge of the correlations between generative parameters and component properties, as well as of the interdependency between the additive process and the subsequent machining process to tune the former to the latter was essential. To ascertain this behaviour, a suitable test part was designed to perform both additive processes using laser metal wire deposition with a closed loop control of the track height and subtractive processes using external and internal longitudinal turning with varied parameters. The so manufactured test parts were then used to qualify the material deposition and turning process by criteria like shape accuracy and surface quality.

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Circular saw blades are very widespread in wood machining. They are used in different batches and sizes and in large quantities from hand tools to large machining centers. Because of this huge range of applications the circular saws have gained great importance in the industry. The rising request to improve the cutting quality, reduce the noise emission and increase the life time requires improvement measures for the dynamic behavior of the circular saw blade. The roll tensioning of the circular saw blade has been empirically established as an elegant solution to improve the static and dynamic properties of the circular saw blade. However, there are several influencing parameters for this process that have not yet been studied scientifically accurate. A scientific and economical solution for the study of various roll tensioning parameters is a simulation model based on finite elements method (FEM) that analyzes the effects on the dynamic behavior of circular saw blade. In this work, a simulation model for roll tensioning of circular saw blades is presented. With this simulation model, the residual stresses induced by the roll tensioning can be calculated. This is very relevant for the changing of dynamic properties of the circular saw blade, such as the shifting of eigenvalues and reduction of side run out. Furthermore, this simulation model allows the investigation of various roll tensioning parameters. This investigation helps to gain a better understanding of the relationship between roll tensioning and improvement of dynamic behavior of circular saw blades. Furthermore, it helps to find the optimization potential of the roll tensioning process which is one of the most important parts of the production line of circular saw blades.

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Kurzfassung Aktuell existieren keine direkten und zuverlässigen Methoden für die Bestimmung der Gleitwiderstandskraft, welche die Reibungsbedingungen an den Kontaktoberflächen beim Zerspanen sicherstellen. Die größten Schwierigkeiten hierzu liegen in der Gewährleistung der chemisch-physikalischen Phänomene, die während des Zerspanens im Kontakt herrschen. Für die Modellierung der Wechselwirkungen im Kontakt wird sehr oft das Coulomb'sche Gesetz verwendet, ungeachtet der Nichtübereinstimmung der Prozesse in der Kontaktzone. Dies steht aber im Widerspruch zu den modernen Erkenntnissen über die wirkenden Reibungsprozesse im Werkzeug-Werkstück-Kontakt.

Kurzfassung Im 1. Teil der Artikelreihe zum Thema Modellierung von Zerspanprozessen wurden die Modellierung der thermomechanischen Wechselwirkungsprozesse und die Reibung zwischen Werkzeug und Werkstück bei der Erstellung von FEM-Modellen des Zerspanprozesses behandelt. Der 2. Teil beschäftigte sich mit der Realisierung der Bruchkriterien beim Modellieren der Zerspanprozesse für unterschiedliche Metalle und Legierungen, für die eine Annahme über die Isotropie und Homogenität des zu bearbeitenden Materials getroffen werden kann. Im hier vorliegenden 3. Teil werden thermomechanische Materialmodelle zur Modellierung von Zerspanprozessen vorgestellt. Die Besonderheiten von Zerspanprozessen stellen spezifische Anforderungen an die Charakteristiken der mechanischen Eigenschaften des zu bearbeitenden Werkstoffs. Für die Realisierung eines allgemein anerkannten und kompletten FE-Zerspanmodells bei praxisgerechten Schnittparametern sollte daher die Bestimmungsgleichung als eine integrale thermo-mechanische Charakteristik des zu bearbeitenden Werkstoffs die Zusammensetzung der drei grundlegenden Parameter des Deformationsprozesses (plastische Deformationen, Intensität der Deformationsgeschwindigkeit und Zerspantemperatur) mit der Fließgrenze plausibel widerspiegeln. Der 4. Teil mit der Beschreibung der FEM-Modellierung als moderner Ansatz zur Untersuchung und Optimierung von Zerspanprozessen schließt die Artikelreihe ab.