@misc{IsrarBuhlBambach, author = {Israr, Rameez and Buhl, Johannes and Bambach, Markus}, title = {A study on power-controlled wire-arc additive manufacturing using a data-driven surrogate model}, series = {The International Journal of Advanced Manufacturing Technology}, volume = {177}, journal = {The International Journal of Advanced Manufacturing Technology}, number = {7-8}, issn = {1433-3015}, doi = {10.1007/s00170-021-07358-y}, pages = {2133 -- 2147}, abstract = {Wire-arc additive manufacturing (WAAM) provides an alternative for the production of various metal products needed in medium to large batch sizes due to its high deposition rates. However, the cyclic heat input in WAAM may cause local overheating. To avoid adverse effects on the performance of the part, interlayer dwelling and active cooling are used, but these measures increase the process time. Alternatively, the temperature during the WAAM process could be controlled by optimizing the welding power. The present work aims at introducing and implementing a novel temperature management approach by adjusting the weld-bead cross-section along with the welding power to reduce the heat accumulation in the WAAM process. The temperature evolution during welding of weld beads of different cross-sections is investigated and a database of the relation between optimal welding power for beads of various sizes and different pre-heating temperatures was established. The numerical results are validated experimentally with a block-shaped geometry. The results show that by the proposed method, the test shape made was welded with lower energy consumption and process time as compared to conventional constant-power WAAM. The proposed approach efficiently manages the thermal input and reduces the need for pausing the process. Hence, the defects related to heat accumulation might be reduced, and the process efficiency increased.}, language = {en} } @incollection{IsrarBuhl, author = {Israr, Rameez and Buhl, Johannes}, title = {An Introduction to Additive Manufacturing (AM) of Metals and Its Trends in Wire-Arc Additive Manufacturing (WAAM) Simulations}, series = {Machine Tools : An Industry 4.0 Perspective}, booktitle = {Machine Tools : An Industry 4.0 Perspective}, editor = {Khan, Wasim Ahmed}, publisher = {CRC Press}, address = {Boca Raton}, doi = {10.1201/9781003220985}, pages = {12}, language = {en} } @misc{IsrarBuhlHaerteletal., author = {Israr, Rameez and Buhl, Johannes and H{\"a}rtel, Sebastian and Bambach, Markus}, title = {Reinforcement of Tooling Using Residual Stresses Generated by Cladding by Arc Welding}, series = {Metals}, volume = {12}, journal = {Metals}, number = {6}, issn = {2075-4701}, doi = {10.3390/met12060984}, pages = {30}, abstract = {Cladding is typically used to protect components from wear and corrosion while also improving the aesthetic value and reliability of the substrate. The cladding process induces significant residual stresses due to the temperature difference between the substrate and the clad layer. However, these residual stresses could be effectively utilized by modifying processes and geometrical parameters. This paper introduces a novel methodology for using the weld-cladding process as a cost-effective alternative to various existing reinforcement techniques. The numerical analyses are performed to maximize the reinforcement of a cylindrical tool. The investigation of how the weld cladding develops compressive stresses on the specimen in response to a change in the weld beads and the welding sequence is presented. For the benchmark shape, experimental verification of the numerical model is performed. The influence of the distance between the weld beads and the effect of the tool diameter is numerically investigated. Furthermore, the variation in compressive stresses due to temperature fluctuations during the extrusion process has been evaluated. The results showed that adequate compressive stresses are generated on the welded parts through the cladding process after cooling. More compressive stresses are induced in the tool as the cross-section of the weld bead is increased. Furthermore, keeping a gap between the adjacent beads improves tool reinforcement. Hence, the targeted reinforcement of the substrate can be achieved by optimizing the welding sequence and process parameters.}, language = {en} } @misc{SefidiIsrarBuhletal., author = {Sefidi, Moein Pakdel and Israr, Rameez and Buhl, Johannes and Bambach, Markus}, title = {Rule-Based Path Identification for Direct Energy Deposition}, series = {Procedia Manufacturing; Part of Special issue: 23rd International Conference on Material Forming}, volume = {47}, journal = {Procedia Manufacturing; Part of Special issue: 23rd International Conference on Material Forming}, editor = {Bambach, Markus}, issn = {2351-9789}, doi = {10.1016/jpromfg.2020.04.133}, pages = {1134 -- 1140}, language = {en} } @misc{BuhlKloeppelMertenetal., author = {Buhl, Johannes and Kl{\"o}ppel, Thomas and Merten, Mathias and Haufe, Andre and Israr, Rameez and Bambach, Markus}, title = {Numerical prediction of process-dependent properties of high-performance Ti6Al4 in LS-DYNA}, series = {ESAFORM 2021 : 24th International Conference on Material Forming}, journal = {ESAFORM 2021 : 24th International Conference on Material Forming}, doi = {doi: 10.25518/esaform21.1496}, language = {en} } @misc{NguyenBuhlIsraretal., author = {Nguyen, Lam and Buhl, Johannes and Israr, Rameez and Bambach, Markus}, title = {Analysis and compensation of shrinkage and distortion in wire-arc additive manufacturing of thin-walled curved hollow sections}, series = {Additive Manufacturing}, volume = {Vol. 47}, journal = {Additive Manufacturing}, issn = {2214-8604}, doi = {10.1016/j.addma.2021.102365}, language = {en} } @misc{IsrarBuhlBambach, author = {Israr, Rameez and Buhl, Johannes and Bambach, Markus}, title = {Numerical Analysis of Different Fixation Strategies in Direct Energy Deposition Processes}, series = {Procedia Manufacturing; Part of Special issue: 23rd International Conference on Material Forming; edited by Markus Bambach}, volume = {47}, journal = {Procedia Manufacturing; Part of Special issue: 23rd International Conference on Material Forming; edited by Markus Bambach}, editor = {Bambach, Markus}, issn = {2351-9789}, doi = {10.1016/j.promfg.2020.04.145}, pages = {1184 -- 1189}, language = {en} } @misc{BuhlIsrarBambach, author = {Buhl, Johannes and Israr, Rameez and Bambach, Markus}, title = {Modeling and convergence analysis of directed energy deposition simulations with hybrid implicit / explicit and implicit solutions}, series = {Journal of Machine Engineering}, volume = {Vol. 19}, journal = {Journal of Machine Engineering}, number = {3}, issn = {2391-8071}, doi = {10.5604/01.3001.0013.4086}, pages = {94 -- 107}, language = {en} } @incollection{BeisegelBuhlIsraretal., author = {Beisegel, Jesse and Buhl, Johannes and Israr, Rameez and Schmidt, Johannes and Bambach, Martin and F{\"u}genschuh, Armin}, title = {Mixed-Integer Programming Models for Two Metal Additive Manufacturing Methods}, series = {Mathematical Methods for Objects Reconstruction}, booktitle = {Mathematical Methods for Objects Reconstruction}, editor = {Cristiani, Emiliano and Falcone, Maurizio and Tozza, Silvia}, publisher = {Springer}, address = {Heidelberg}, isbn = {978-981-9907-75-5}, pages = {121 -- 155}, language = {en} }