TY - GEN A1 - Li, Zheng A1 - Pasternak, Hartmut A1 - Ciupack, Yvonne ED - Zingoni, Alphose T1 - Artificial neural network prediction of bearing capacity of welded columns based on simplified welding simulations T2 - Advances in engineering materials, structures and systems : innovations, mechanics and applications : proceedings of the 7th International Conference on Structural Engineering, Mechanics, and Computation (SEMC 2019), September 2-4, 2019, Cape Town, South Africa Y1 - 2019 SN - 978-1-138-38696-9 SP - 1219 EP - 1223 PB - Taylor & Francis Group CY - London ER - TY - GEN A1 - Launert, Benjamin A1 - Li, Zheng A1 - Pasternak, Hartmut ED - Zingoni, Alphose T1 - Development of a new method for the direct numerical consideration of welding effects in the component design of welded plate girders T2 - Advances in engineering materials, structures and systems : innovations, mechanics and applications : proceedings of the 7th International Conference on Structural Engineering, Mechanics, and Computation (SEMC 2019), September 2-4, 2019, Cape Town, South Africa Y1 - 2019 SN - 978-1-138-38696-9 SP - 1143 EP - 1147 PB - Taylor & Francis Group CY - London ER - TY - GEN A1 - Pasternak, Hartmut A1 - Krausche, Thomas ED - Zingoni, Alphose T1 - Details and assembly of two cladded double curved cable net roofs T2 - Advances in engineering materials, structures and systems : innovations, mechanics and applications : proceedings of the 7th International Conference on Structural Engineering, Mechanics, and Computation (SEMC 2019), September 2-4, 2019, Cape Town, South Africa Y1 - 2019 SN - 978-1-138-38696-9 SP - 896 EP - 901 PB - Taylor & Francis Group CY - London ER - TY - GEN A1 - Ciupack, Yvonne A1 - Pasternak, Hartmut A1 - Geßler, Achim A1 - Feldmann, Markus A1 - Kasper, Yann A1 - Albiez, Matthias A1 - Ummenhofer, Thomas T1 - Repair of Fatigue Cracked CT-specimens Using Adhesively Bonded CFRP Lamellas T2 - 27th Annual International Conference on Composites / Nano Engineering ICCE-27 Y1 - 2019 UR - https://www.b-tu.de/fg-stahlbau/publikationen/veroeffentlichungen ER - TY - GEN A1 - Li, Zheng A1 - Pasternak, Hartmut T1 - Statistical size effect of flexural members in steel structures T2 - Journal of Constructional Steel Research N2 - This paper presents the results of theoretical and experimental investigations on the statistical size effect (SSE) of flexural members in steel. The chain of bundle model is developed, which is based on a stochastic material model by Weibull and lognormal distribution. Furthermore, this model is embedded into the finite element method (FEM) software for the analysis of a complicated structure with a stress gradient. In order to determine the stochastic material model parameters, uniaxial tensile tests were carried out based on specimens using the same steel with different sizes. By comparing the experimental and simulation results, the material parameters could be analyzed based on the relationship between the specimen sizes and strength. Moreover, the 3-point and 4-point bending tests were performed and simulated with the developed model. The experimental and simulation results demonstrate that the SSE also exists in the flexural member, and the equivalent yield stress is closely related to the stress distribution and volume of the structure component. Y1 - 2018 U6 - https://doi.org/10.1016/j.jcsr.2018.01.025 SN - 0143-974X VL - 144 SP - 176 EP - 185 ER - TY - GEN A1 - Pasternak, Hartmut A1 - Piekarczyk, Marek T1 - Versuche und FE-Untersuchungen von Wellstegträgern mit Löchern T2 - Konstrukcje Stalowe Y1 - 2006 VL - 5 IS - 10 SP - 37 EP - 39 ER - TY - GEN A1 - Pasternak, Hartmut A1 - Schwarzlos, Anja T1 - The application of adhesives in steel structures T2 - Konstrukcje stalowe Y1 - 2003 IS - 5 ER - TY - GEN A1 - Pasternak, Hartmut A1 - Kubieniec, Gabriel A1 - Piekarczyk, Marek T1 - Adhesives in strengthening of steel structures T2 - Engineering structures and technologies Y1 - 2010 SN - 2029-8838 SN - 2029-882X VL - 2 IS - 2 SP - 45 EP - 50 ER - TY - GEN A1 - Pasternak, Hartmut A1 - Schwarzlos, Anja A1 - Schimmack, N. T1 - The application of adhesives to connect steel members T2 - Journal of Constructional Steel research Y1 - 2004 SN - 0143-974X VL - 60 IS - 3-5 SP - 649 EP - 658 ER - TY - GEN A1 - Li, Zheng A1 - Xu, Siying A1 - Geißler, Karsten A1 - Wang, Jian A1 - Pasternak, Hartmut T1 - Developed numerical Analysis of Residual Stress caused by Welding and Cutting in Steel Structures T2 - ce/papers N2 - The welding and flame‐cutting process in the steel construction are commonly used, especially for the bridge structure. Some experiments about welding and cutting have been done separately by some researchers. The results from the experiments were also compared with the results from the numerical simulation under 3D or 2D models. The agreements between those results are as good as they predicted. Therefore, the numerical simulation is a better way to analyze the quality of the steel construction after welding and cutting without time‐consuming and a large amount of cost. But there are only a few research about the numerical simulation and the some of them are aimed to verify the experiments. In this study, the calculation about the residual stresses after welding and thermo‐cutting are considered from 3D‐model into 2D‐Model. The heat source model is simply regarded as curves of time and welding energy with the algorithm methods. And no matter the change of the parameters of the model and the heat source, the heat transfer and the residual stresses can be calculated with the 2D models as fast as possible. By the means of the finite element software Abaqus, the I‐profiles are easy to receive the job results with the input parameters. The influence of the welding and cutting process are visual and direct. KW - Welding KW - Flame cutting KW - Numerical simulation KW - Residual stress KW - Steel structures Y1 - 2023 U6 - https://doi.org/10.1002/cepa.2601 SN - 2509-7075 VL - 6 IS - 3-4 SP - 1507 EP - 1512 ER - TY - GEN A1 - Pasternak, Hartmut A1 - Li, Zheng A1 - Stapelfeld, Christoph A1 - Jäger-Cañás, Andreas A1 - Launert, Benjamin T1 - Considering realistic weld imperfections in load bearing capacity calculations of ring-stiffened shells using the analytical numerical hybrid model T2 - Stability and Ductility of Steel Structures 2019 : Proceedings of the International Colloquia on Stability and Ductility of Steel Structures (SDSS 2019), September 11-13, 2019, Prague, Czech Republic Y1 - 2019 SN - 978-0-429-32024-8 SN - 978-0-367-33503-8 U6 - https://doi.org/10.1201/9780429320248 SP - 882 EP - 889 PB - CRC Press CY - London ET - 1st Edition ER - TY - GEN A1 - Jäger-Cañás, Andreas A1 - Li, Zheng A1 - Pasternak, Hartmut T1 - Axial buckling behavior of welded ring-stiffened shells T2 - Stability and Ductility of Steel Structures 2019 : Proceedings of the International Colloquia on Stability and Ductility of Steel Structures (SDSS 2019), September 11-13, 2019, Prague, Czech Republic Y1 - 2019 SN - 978-0-429-32024-8 SN - 978-0-367-33503-8 U6 - https://doi.org/10.1201/9780429320248 SP - 556 EP - 563 PB - CRC Press CY - London ET - 1st Edition ER - TY - GEN A1 - Wang, Jian A1 - Li, Zheng A1 - Robra, Jörgen A1 - Pasternak, Hartmut A1 - Euler, Mathias T1 - Investigation on Shear Buckling of Corrugated Web Beams with Reinforced Web Openings T2 - ce/papers N2 - Corrugated web beams are welded I‐sections with thin‐walled sinusoidal corrugated webs and flanges made of wide flat steel that have been developed as an alternative to steel girders with flat webs. In comparison with hot‐rolled or welded I‐beams with flat webs, corrugated web beams are connected with considerable material savings and fully automated production. Assuming the same load‐bearing capacity, corrugated web beams are lighter than those with a flat web, since the corrugated web beams can often be loaded up to their plastic resistance without reinforcement of the web. The research on the load‐bearing behavior of corrugated web beams without web openings is relatively mature. However, the resistance of corrugated web beams with reinforced web openings, as they are often used in buildings for installations, has not well experimentally been investigated, yet. This paper deals with the shear resistance of corrugated web beams with reinforced square web openings. Three specimens of different geometry with two square web openings were tested. The experiments are compared with a Finite Element Analysis by Abaqus® and with an analytical model allowing simplified calculation. Both models can relatively accurately calculate the shear resistance. The experimental and numerical results show that the increase of the shear resistance of perforated corrugated web beams depends on the wall‐thickness and the steel grade of the web opening reinforcement. KW - Corrugated web beams KW - square web openings KW - ring stiffener KW - local shear buckling KW - experimental investigation KW - finite element analysis Y1 - 2022 U6 - https://doi.org/10.1002/cepa.1800 SN - 2509-7075 VL - 5 IS - 4 SP - 628 EP - 634 ER - TY - GEN A1 - Li, Zheng A1 - Zhang, Qiulei A1 - Shi, Fei A1 - Wang, Jian A1 - Pasternak, Hartmut T1 - Geometric Properties of Steel Components with Stability and Fatigue Risks Using 3D-Laser-Scanning T2 - Buildings N2 - Nowadays, 3D laser scanning technology is extensively employed in laboratory investigations of steel structural components, providing accurate geometric dimensions to reduce uncertainties caused by indeterminate geometry in experimental results. It is often used in conjunction with the Finite Element (FE) Method and analytical solutions, which are more accurate deterministic operators in the research on steel structures. However, establishing a common methodological framework for transferring or mapping 3D-scanned information into finite element models for complex steel structures with stability and fatigue risks remains an ongoing task. In light of this, this study has developed a 3D scanning platform capable of obtaining accurate geometric dimensions for various types of steel components. Different coordinate systems and point cloud mapping algorithms have been established for different types of components to construct actual finite element models with initial imperfections. The feasibility of the self-developed 3D scanning platform and finite element modelling has been validated through three experimental cases: weld details, steel girders, and cylindrical shells. The research findings demonstrate that the captured point cloud can be automatically processed and corrected using the developed algorithm. The scanned data can then be input into the numerical model using various mapping algorithms tailored to the specific geometric properties of the specimens. The differences between the experimental test results and the simulated results obtained from the 3D-scanned finite element models remain within a small range. The self-developed 3D scanning platform and finite element modelling technique effectively capture the actual dimensions of different steel components, enabling the prediction of their stability and fatigue risks through numerical simulations. KW - 3D laser scanning KW - steel structures KW - geometric properties KW - stability KW - fatigue Y1 - 2024 U6 - https://doi.org/10.3390/buildings14010168 SN - 2075-5309 VL - 14 IS - 1 ER -