@article{MoscosoKraus,
  author    = {Moscoso, Caridad and Kraus, Matthias},
  title     = {On the Verification of Beams Subjected to Lateral Torsional Buckling by Simplified Plastic Structural Analysis},
  series = {ce/papers},
  volume    = {2022},
  journal   = {ce/papers},
  number    = {Volume 5, Issue 4},
  publisher = {Ernst \& Sohn},
  address   = {Berlin},
  doi       = {10.1002/cepa.1835},
  url       = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20230124-48782},
  pages     = {914 -- 923},
  abstract  = {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.},
  subject      = {Stahl},
  language  = {en}
}
@article{KrausKlausWittor,
  author    = {Kraus, Matthias and Klaus, Martin and Wittor, Bj{\"o}rn},
  title     = {Experimental Analyses on the Resistance of Tapped Blind Holes},
  series = {ce/papers},
  volume    = {2021},
  journal   = {ce/papers},
  number    = {Volume 4, issue 2-4},
  publisher = {Ernst \& Sohn, a Wiley brand},
  address   = {Berlin},
  doi       = {10.1002/cepa.1273},
  url       = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20220112-45553},
  pages     = {141 -- 147},
  abstract  = {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.},
  subject      = {Gewinde},
  language  = {en}
}
@article{KrausCrişanWittor,
  author    = {Kraus, Matthias and Cri{\c{s}}an, Nicolae-Andrei and Wittor, Bj{\"o}rn},
  title     = {Stability Study of Cantilever-Beams - Numerical Analysis and Analytical Calculation (LTB)},
  series = {ce/papers},
  volume    = {2021},
  journal   = {ce/papers},
  number    = {Volume 4, issue 2-4},
  publisher = {Ernst \& Sohn, a Wiley brand},
  address   = {Berlin},
  doi       = {10.1002/cepa.1539},
  url       = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20220112-45637},
  pages     = {2199 -- 2206},
  abstract  = {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).},
  subject      = {Tr{\"a}ger},
  language  = {en}
}
@article{IlyaniAkmarKramerRabczuk,
  author    = {Ilyani Akmar, A.B. and Kramer, O. and Rabczuk, Timon},
  title     = {Multi-objective evolutionary optimization of sandwich structures: An evaluation by elitist non-dominated sorting evolution strategy},
  series = {American Journal of Engineering and Applied Sciences},
  journal   = {American Journal of Engineering and Applied Sciences},
  doi       = {10.3844/ajeassp.2015.185.201},
  url       = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20170418-31402},
  pages     = {185 -- 201},
  abstract  = {In this study, an application of evolutionary multi-objective optimization algorithms on the optimization of sandwich structures is presented. The solution strategy is known as Elitist Non-Dominated Sorting Evolution Strategy (ENSES) wherein Evolution Strategies (ES) as Evolutionary Algorithm (EA) in the elitist Non-dominated Sorting Genetic algorithm (NSGA-II) procedure. Evolutionary algorithm seems a compatible approach to resolve multi-objective optimization problems because it is inspired by natural evolution, which closely linked to Artificial Intelligence (AI) techniques and elitism has shown an important factor for improving evolutionary multi-objective search. In order to evaluate the notion of performance by ENSES, the well-known study case of sandwich structures are reconsidered. For Case 1, the goals of the multi-objective optimization are minimization of the deflection and the weight of the sandwich structures. The length, the core and skin thicknesses are the design variables of Case 1. For Case 2, the objective functions are the fabrication cost, the beam weight and the end deflection of the sandwich structures. There are four design variables i.e., the weld height, the weld length, the beam depth and the beam width in Case 2. Numerical results are presented in terms of Paretooptimal solutions for both evaluated cases.},
  subject      = {Optimierung},
  language  = {en}
}
@article{IbanezKraus,
  author    = {Ibanez, Stalin and Kraus, Matthias},
  title     = {A Numerical Approach for Plastic Cross Cross-Sectional Analyses of Steel Members},
  series = {ce/papers},
  volume    = {2021},
  journal   = {ce/papers},
  number    = {Volume 4, issue 2-4},
  publisher = {Ernst \& Sohn, a Wiley brand},
  address   = {Berlin},
  doi       = {10.1002/cepa.1527},
  url       = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20220112-45622},
  pages     = {2098 -- 2106},
  abstract  = {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.},
  subject      = {Stahlkonstruktion},
  language  = {en}
}
@article{FaridmehrTahirLahmer,
  author    = {Faridmehr, Iman and Tahir, Mamood Md. and Lahmer, Tom},
  title     = {Classification System for Semi-Rigid Beam-to-Column Connections},
  series = {LATIN AMERICAN JOURNAL OF SOLIDS AND STRUCTURES 11},
  journal   = {LATIN AMERICAN JOURNAL OF SOLIDS AND STRUCTURES 11},
  doi       = {10.1590/1679-78252595},
  url       = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20170401-30988},
  pages     = {2152 -- 2175},
  abstract  = {The current study attempts to recognise an adequate classification for a semi-rigid beam-to-column connection by investigating strength, stiffness and ductility. For this purpose, an experimental test was carried out to investigate the moment-rotation (M-theta) features of flush end-plate (FEP) connections including variable parameters like size and number of bolts, thickness of end-plate, and finally, size of beams and columns. The initial elastic stiffness and ultimate moment capacity of connections were determined by an extensive analytical procedure from the proposed method prescribed by ANSI/AISC 360-10, and Eurocode 3 Part 1-8 specifications. The behaviour of beams with partially restrained or semi-rigid connections were also studied by incorporating classical analysis methods. The results confirmed that thickness of the column flange and end-plate substantially govern over the initial rotational stiffness of of flush end-plate connections. The results also clearly showed that EC3 provided a more reliable classification index for flush end-plate (FEP) connections. The findings from this study make significant contributions to the current literature as the actual response characteristics of such connections are non-linear. Therefore, such semirigid behaviour should be used to for an analysis and design method.},
  subject      = {Tragf{\"a}higkeit},
  language  = {en}
}