TY - JOUR A1 - Arnold, Robert A1 - Kraus, Matthias ED - Pham, Duc T1 - On the nonstationary identification of climate-influenced loads for the semi-probabilistic approach using measured and projected data JF - Cogent Engineering N2 - A safe and economic structural design based on the semi-probabilistic concept requires statistically representative safety elements, such as characteristic values, design values, and partial safety factors. Regarding climate loads, the safety levels of current design codes strongly reflect experiences based on former measurements and investigations assuming stationary conditions, i.e. involving constant frequencies and intensities. However, due to climate change, occurrence of corresponding extreme weather events is expected to alter in the future influencing the reliability and safety of structures and their components. Based on established approaches, a systematically refined data-driven methodology for the determination of design parameters considering nonstationarity as well as standardized targets of structural reliability or safety, respectively, is therefore proposed. The presented procedure picks up fundamentals of European standardization and extends them with respect to nonstationarity by applying a shifting time window method. Taking projected snow loads into account, the application of the method is exemplarily demonstrated and various influencing parameters are discussed. KW - Reliabilität KW - Extreme value distribution KW - climate loads KW - nonstationarity KW - semi-probabilistic concept KW - First Order Reliability Method KW - OA-Publikationsfonds2022 Y1 - 2022 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:gbv:wim2-20221117-47363 UR - https://doi.org/10.1080/23311916.2022.2143061 VL - 2022 IS - Volume 9, issue 1, article 2143061 SP - 1 EP - 26 PB - Taylor & Francis CY - London ER - TY - JOUR A1 - Chowdhury, Sharmistha A1 - Kraus, Matthias T1 - Design-related reassessment of structures integrating Bayesian updating of model safety factors JF - Results in Engineering N2 - In the semi-probabilistic approach of structural design, the partial safety factors are defined by considering some degree of uncertainties to actions and resistance, associated with the parameters’ stochastic nature. However, uncertainties for individual structures can be better examined by incorporating measurement data provided by sensors from an installed health monitoring scheme. In this context, the current study proposes an approach to revise the partial safety factor for existing structures on the action side, γE by integrating Bayesian model updating. A simple numerical example of a beam-like structure with artificially generated measurement data is used such that the influence of different sensor setups and data uncertainties on revising the safety factors can be investigated. It is revealed that the health monitoring system can reassess the current capacity reserve of the structure by updating the design safety factors, resulting in a better life cycle assessment of structures. The outcome is furthermore verified by analysing a real life small railway steel bridge ensuring the applicability of the proposed method to practical applications. KW - Lebenszyklus KW - Sicherheitsfaktor KW - Structural health monitoring KW - Safety factor KW - Life cycle assessment KW - Uncertainty KW - Bayesian parameter update KW - Ungewissheit KW - Umweltbilanz KW - OA-Publikationsfonds2022 Y1 - 2022 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:gbv:wim2-20221028-47294 UR - https://www.sciencedirect.com/science/article/pii/S2590123022002304?via%3Dihub VL - 2022 IS - Volume 16, article 100560 SP - 1 EP - 1 PB - Elsevier CY - Amsterdam ER - TY - JOUR A1 - Ibanez, Stalin A1 - Kraus, Matthias T1 - A Numerical Approach for Plastic Cross Cross-Sectional Analyses of Steel Members JF - ce/papers N2 - Global structural analyses in civil engineering are usually performed considering linear-elastic material behavior. However, for steel structures, a certain degree of plasticization depending on the member classification may be considered. Corresponding plastic analyses taking material nonlinearities into account are effectively realized using numerical methods. Frequently applied finite elements of two and three-dimensional models evaluate the plasticity at defined nodes using a yield surface, i.e. by a yield condition, hardening rule, and flow rule. Corresponding calculations are connected to a large numerical as well as time-consuming effort and they do not rely on the theoretical background of beam theory, to which the regulations of standards mainly correspond. For that reason, methods using beam elements (one-dimensional) combined with cross-sectional analyses are commonly applied for steel members in terms of plastic zones theories. In these approaches, plasticization is in general assessed by means of axial stress only. In this paper, more precise numerical representation of the combined stress states, i.e. axial and shear stresses, is presented and results of the proposed approach are validated and discussed. KW - Stahlkonstruktion KW - Plastizität KW - Strukturanalyse KW - Stahlbauteil KW - Axialspannung KW - Finite-Elemente-Methode Y1 - 2021 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:gbv:wim2-20220112-45622 UR - https://onlinelibrary.wiley.com/doi/full/10.1002/cepa.1527 VL - 2021 IS - Volume 4, issue 2-4 SP - 2098 EP - 2106 PB - Ernst & Sohn, a Wiley brand CY - Berlin ER - TY - JOUR A1 - Kraus, Matthias A1 - Crişan, Nicolae-Andrei A1 - Wittor, Björn T1 - Stability Study of Cantilever-Beams – Numerical Analysis and Analytical Calculation (LTB) JF - ce/papers N2 - According to Eurocode, the computation of bending strength for steel cantilever beams is a straightforward process. The approach is based on an Ayrton-Perry formula adaptation of buckling curves for steel members in compression, which involves the computation of an elastic critical buckling load for considering the instability. NCCI documents offer a simplified formula to determine the critical bending moment for cantilevers beams with symmetric cross-section. Besides the NCCI recommendations, other approaches, e.g. research literature or Finite-Element-Analysis, may be employed to determine critical buckling loads. However, in certain cases they render different results. Present paper summarizes and compares the abovementioned analytical and numerical approaches for determining critical loads and it exemplarily analyses corresponding cantilever beam capacities using numerical approaches based on plastic zones theory (GMNIA). KW - Träger KW - Stahl KW - Biegefestigkeit KW - Finite-Elemente-Methode KW - Stahlträger KW - Knicklast KW - Freiträgerkapazität KW - Eurocode Y1 - 2021 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:gbv:wim2-20220112-45637 UR - https://onlinelibrary.wiley.com/doi/full/10.1002/cepa.1539 VL - 2021 IS - Volume 4, issue 2-4 SP - 2199 EP - 2206 PB - Ernst & Sohn, a Wiley brand CY - Berlin ER - TY - JOUR A1 - Kraus, Matthias A1 - Klaus, Martin A1 - Wittor, Björn T1 - Experimental Analyses on the Resistance of Tapped Blind Holes JF - ce/papers N2 - Bolted connections are commonly used in steel construction. The load-bearing behavior of bolt fittings has extensively been studied in various research activities and the bearing capacity of bolted connections can be assessed well by standard regulations for practical applications. With regard to tensile loading, the nut does not have strong influence on resistances, since the failure occurs in the bolts due to higher material strengths of the nuts. In some applications, so-called “blind holes” are used to connect plated components. In a manner of speaking, the nut is replaced by the “outer” plate with a prefabricated hole and thread, in which the bolt can be screwed and tightened. In such connections, the limit load capacity cannot solely be assessed by the bolt resistance, since the threaded hole in the base material has strong influence on the structural behavior. In this context, the available screw-in depth of the blind hole is of fundamental importance. The German National Annex of EN 1993-1-8 provides information on a necessary depth in order to transfer the full tensile capacity of the bolt. However, some connections do not allow to fabricate such depths. In these cases, the capacity of the connection is unclear and not specified. In this paper, first experiments on corresponding connections with different screw-in depths are presented and compared to limit load capacities according to the standard. KW - Gewinde KW - Bolzen KW - threat KW - bolt KW - tapped blind holes Y1 - 2021 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:gbv:wim2-20220112-45553 UR - https://onlinelibrary.wiley.com/doi/10.1002/cepa.1273 VL - 2021 IS - Volume 4, issue 2-4 SP - 141 EP - 147 PB - Ernst & Sohn, a Wiley brand CY - Berlin ER - TY - JOUR A1 - Moscoso, Caridad A1 - Kraus, Matthias T1 - On the Verification of Beams Subjected to Lateral Torsional Buckling by Simplified Plastic Structural Analysis JF - ce/papers N2 - Plastic structural analysis may be applied without any difficulty and with little effort for structural member verifications with regard to lateral torsional buckling of doubly symmetric rolled I sections. Suchlike analyses can be performed based on the plastic zone theory, specifically using finite beam elements with seven degrees of freedom and 2nd order theory considering material nonlinearity. The existing Eurocode enables these approaches and the coming-up generation will provide corresponding regulations in EN 1993-1-14. The investigations allow the determination of computationally accurate limit loads, which are determined in the present paper for selected structural systems with different sets of parameters, such as length, steel grade and cross section types. The results are compared to approximations gained by more sophisticated FEM analyses (commercial software Ansys Workbench applying solid elements) for reasons of verification/validation. In this course, differences in the results of the numerical models are addressed and discussed. In addition, results are compared to resistances obtained by common design regulations based on reduction factors χlt including regulations of EN 1993-1-1 (including German National Annex) as well as prEN 1993-1-1: 2020-08 (proposed new Eurocode generation). Concluding, correlations of results and their advantages as well as disadvantages are discussed. KW - Stahl KW - Träger KW - Robustheit KW - steel KW - stability KW - flexural-torsional-buckling Y1 - 2022 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:gbv:wim2-20230124-48782 UR - https://onlinelibrary.wiley.com/doi/full/10.1002/cepa.1835 VL - 2022 IS - Volume 5, Issue 4 SP - 914 EP - 923 PB - Ernst & Sohn CY - Berlin ER - TY - JOUR A1 - Sirtl, Christin A1 - Hadlich, Christiane A1 - Kraus, Matthias A1 - Osburg, Andrea T1 - Determination of Bonding Failures in Transparent Materials with Non-Destructive Methods – Evaluation of Climatically Stressed Glued and Laminated Glass Compounds JF - World Journal of Engineering and Technology N2 - As part of an international research project – funded by the European Union – capillary glasses for facades are being developed exploiting storage energy by means of fluids flowing through the capillaries. To meet highest visual demands, acrylate adhesives and EVA films are tested as possible bonding materials for the glass setup. Especially non-destructive methods (visual analysis, analysis of birefringent properties and computed tomographic data) are applied to evaluate failure patterns as well as the long-term behavior considering climatic influences. The experimental investigations are presented after different loading periods, providing information of failure developments. In addition, detailed information and scientific findings on the application of computed tomographic analyses are presented. KW - Klebtechnik KW - Non-Destructive Testing KW - Bonding Methods KW - OA-Publikationsfonds2018 Y1 - 2018 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:gbv:wim2-20180606-37526 UR - http://www.scirp.org/journal/PaperInformation.aspx?PaperID=84507 VL - 2018 IS - Vol. 6, No 2 SP - 315 EP - 331 ER - TY - CHAP A1 - Sirtl, Christin A1 - Kraus, Matthias T1 - Bonding Quality of Joined Glass Components Exposed to UV and Fluidic Influences N2 - Components of structural glazing have to meet different requirements and resist various impacts, depending on the field of application. Within an international research project of the EU innovation program Horizon 2020, special glass panes with a fluid circulating in capillaries are developed exploiting solar energy. Major influences to this glazing are UV irradiation and the fluidic contact, effecting the mechanical and optical durability of the bonding material within the glass setup. Regarding to visual requirements, acrylate adhesives and EVA films are analyzed as possible bonding materials by destructive and non-destructive testing methods. Two types of specimen are presented for obtaining the mechanical behavior and the surface appearances of the bonding material. KW - Alterung KW - long-term examination KW - material aging KW - climatic loading KW - non-destructive testing KW - destructive testin Y1 - 2018 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:gbv:wim2-20190514-39144 UR - https://onlinelibrary.wiley.com/doi/epdf/10.1002/cepa.940 SN - 978-3-433-03269-5 N1 - Dies ist die Manuskriptfassung zu folgender Veröffentlichung : https://doi.org/10.1002/cepa.940, https://onlinelibrary.wiley.com/doi/full/10.1002/cepa.940 PB - Ernst & Sohn Verlag für Architektur und technische Wissenschaften GmbH & Co. KG CY - Berlin ER -