@article{AbdelnourZabel,
  author    = {Abdelnour, Mena and Zabel, Volkmar},
  title     = {Modal identification of structures with a dynamic behaviour characterised by global and local modes at close frequencies},
  series = {Acta Mechanica},
  volume    = {2023},
  journal   = {Acta Mechanica},
  publisher = {Springer},
  address   = {Wien},
  doi       = {10.1007/s00707-023-03598-z},
  url       = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20230525-63822},
  pages     = {1 -- 21},
  abstract  = {Identification of modal parameters of a space frame structure is a complex assignment due to a large number of degrees of freedom, close natural frequencies, and different vibrating mechanisms. Research has been carried out on the modal identification of rather simple truss structures. So far, less attention has been given to complex three-dimensional truss structures. This work develops a vibration-based methodology for determining modal information of three-dimensional space truss structures. The method uses a relatively complex space truss structure for its verification. Numerical modelling of the system gives modal information about the expected vibration behaviour. The identification process involves closely spaced modes that are characterised by local and global vibration mechanisms. To distinguish between local and global vibrations of the system, modal strain energies are used as an indicator. The experimental validation, which incorporated a modal analysis employing the stochastic subspace identification method, has confirmed that considering relatively high model orders is required to identify specific mode shapes. Especially in the case of the determination of local deformation modes of space truss members, higher model orders have to be taken into account than in the modal identification of most other types of structures.},
  subject      = {Fachwerkbau},
  language  = {en}
}
@article{ZhangRen,
  author    = {Zhang, Yongzheng and Ren, Huilong},
  title     = {Implicit implementation of the nonlocal operator method: an open source code},
  series = {Engineering with computers},
  volume    = {2022},
  journal   = {Engineering with computers},
  publisher = {Springer},
  address   = {London},
  doi       = {10.1007/s00366-021-01537-x},
  url       = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20220216-45930},
  pages     = {1 -- 35},
  abstract  = {In this paper, we present an open-source code for the first-order and higher-order nonlocal operator method (NOM) including a detailed description of the implementation. The NOM is based on so-called support, dual-support, nonlocal operators, and an operate energy functional ensuring stability. The nonlocal operator is a generalization of the conventional differential operators. Combined with the method of weighed residuals and variational principles, NOM establishes the residual and tangent stiffness matrix of operate energy functional through some simple matrix without the need of shape functions as in other classical computational methods such as FEM. NOM only requires the definition of the energy drastically simplifying its implementation. The implementation in this paper is focused on linear elastic solids for sake of conciseness through the NOM can handle more complex nonlinear problems. The NOM can be very flexible and efficient to solve partial differential equations (PDEs), it's also quite easy for readers to use the NOM and extend it to solve other complicated physical phenomena described by one or a set of PDEs. Finally, we present some classical benchmark problems including the classical cantilever beam and plate-with-a-hole problem, and we also make an extension of this method to solve complicated problems including phase-field fracture modeling and gradient elasticity material.},
  subject      = {Strukturmechanik},
  language  = {en}
}
@article{Zhang,
  author    = {Zhang, Yongzheng},
  title     = {Nonlocal dynamic Kirchhoff plate formulation based on nonlocal operator method},
  series = {Engineering with Computers},
  volume    = {2022},
  journal   = {Engineering with Computers},
  publisher = {Springer},
  address   = {London},
  doi       = {10.1007/s00366-021-01587-1},
  url       = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20220209-45849},
  pages     = {1 -- 35},
  abstract  = {In this study, we propose a nonlocal operator method (NOM) for the dynamic analysis of (thin) Kirchhoff plates. The nonlocal Hessian operator is derived based on a second-order Taylor series expansion. The NOM does not require any shape functions and associated derivatives as 'classical' approaches such as FEM, drastically facilitating the implementation. Furthermore, NOM is higher order continuous, which is exploited for thin plate analysis that requires C1 continuity. The nonlocal dynamic governing formulation and operator energy functional for Kirchhoff plates are derived from a variational principle. The Verlet-velocity algorithm is used for the time discretization. After confirming the accuracy of the nonlocal Hessian operator, several numerical examples are simulated by the nonlocal dynamic Kirchhoff plate formulation.},
  subject      = {Angewandte Mathematik},
  language  = {en}
}
@phdthesis{Hartmann,
  author    = {Hartmann, Veronika},
  title     = {Methoden zur Quantifizierung und Optimierung der Robustheit von Bauablaufpl{\"a}nen},
  doi       = {10.25643/bauhaus-universitaet.4579},
  url       = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20220204-45798},
  school      = {Bauhaus-Universit{\"a}t Weimar},
  abstract  = {Bauablaufpl{\"a}nen kommt bei der Realisierung von Bauprojekten eine zentrale Rolle zu. Sie dienen der Koordination von Schnittstellen und bilden f{\"u}r die am Projekt Beteiligten die Grundlage f{\"u}r ihre individuelle Planung. Eine verl{\"a}ssliche Terminplanung ist daher von großer Bedeutung, tats{\"a}chlich sind aber gerade Bauablaufpl{\"a}ne f{\"u}r ihre Unzuverl{\"a}ssigkeit bekannt. Aufgrund der langen Vorlaufzeiten bei der Planung von Bauprojekten sind zum Zeitpunkt der Planung viele Informationen nur als Sch{\"a}tzwerte bekannt. Auf der Grundlage dieser gesch{\"a}tzten und damit mit Unsicherheiten behafteten Daten werden im Bauwesen deterministische Terminpl{\"a}ne erstellt. Kommt es w{\"a}hrend der Realisierung zu Diskrepanzen zwischen Sch{\"a}tzungen und Realit{\"a}t, erfordert dies die Anpassung der Pl{\"a}ne. Aufgrund zahlreicher Abh{\"a}ngigkeiten zwischen den geplanten Aktivit{\"a}ten k{\"o}nnen einzelne Plan{\"a}nderungen vielf{\"a}ltige weitere {\"A}nderungen und Anpassungen nach sich ziehen und damit einen reibungslosen Projektablauf gef{\"a}hrden. In dieser Arbeit wird ein Vorgehen entwickelt, welches Bauablaufpl{\"a}ne erzeugt, die im Rahmen der durch das Projekt definierten Abh{\"a}ngigkeiten und Randbedingungen in der Lage sind, {\"A}nderungen m{\"o}glichst gut zu absorbieren. Solche Pl{\"a}ne, die bei auftretenden {\"A}nderungen vergleichsweise geringe Anpassungen des Terminplans erfordern, werden hier als robust bezeichnet. Ausgehend von Verfahren der Projektplanung und Methoden zur Ber{\"u}cksichtigung von Unsicherheiten werden deterministische Terminpl{\"a}ne bez{\"u}glich ihres Verhaltens bei eintretenden {\"A}nderungen betrachtet. Hierf{\"u}r werden zun{\"a}chst m{\"o}gliche Unsicherheiten als Ursachen f{\"u}r {\"A}nderungen benannt und mathematisch abgebildet. Damit kann das Verhalten von Abl{\"a}ufen f{\"u}r m{\"o}gliche {\"A}nderungen betrachtet werden, indem die durch {\"A}nderungen erzwungenen angepassten Terminpl{\"a}ne simuliert werden. F{\"u}r diese Monte-Carlo-Simulationen der angepassten Terminpl{\"a}ne wird sichergestellt, dass die angepassten Terminpl{\"a}ne logische Weiterentwicklungen des deterministischen Terminplans darstellen. Auf der Grundlage dieser Untersuchungen wird ein stochastisches Maß zur Quantifizierung der Robustheit erarbeitet, welches die F{\"a}higkeit eines Planes, {\"A}nderungen zu absorbieren, beschreibt. Damit ist es m{\"o}glich, Terminpl{\"a}ne bez{\"u}glich ihrer Robustheit zu vergleichen. Das entwickelte Verfahren zur Quantifizierung der Robustheit wird in einem Optimierungsverfahren auf Basis Genetischer Algorithmen angewendet, um gezielt robuste Terminpl{\"a}ne zu erzeugen. An Beispielen werden die Methoden demonstriert und ihre Wirksamkeit nachgewiesen.},
  subject      = {Bauablaufplanung},
  language  = {de}
}
@article{AlkamLahmer,
  author    = {Alkam, Feras and Lahmer, Tom},
  title     = {A robust method of the status monitoring of catenary poles installed along high-speed electrified train tracks},
  series = {Results in Engineering},
  volume    = {2021},
  journal   = {Results in Engineering},
  number    = {volume 12, article 100289},
  publisher = {Elsevier},
  address   = {Amsterdam},
  doi       = {10.1016/j.rineng.2021.100289},
  url       = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20211011-45212},
  pages     = {1 -- 8},
  abstract  = {Electric trains are considered one of the most eco-friendly and safest means of transportation. Catenary poles are used worldwide to support overhead power lines for electric trains. The performance of the catenary poles has an extensive influence on the integrity of the train systems and, consequently, the connected human services. It became a must nowadays to develop SHM systems that provide the instantaneous status of catenary poles in- service, making the decision-making processes to keep or repair the damaged poles more feasible. This study develops a data-driven, model-free approach for status monitoring of cantilever structures, focusing on pre-stressed, spun-cast ultrahigh-strength concrete catenary poles installed along high-speed train tracks. The pro-posed approach evaluates multiple damage features in an unfied damage index, which leads to straightforward interpretation and comparison of the output. Besides, it distinguishes between multiple damage scenarios of the poles, either the ones caused by material degradation of the concrete or by the cracks that can be propagated during the life span of the given structure. Moreover, using a logistic function to classify the integrity of structure avoids the expensive learning step in the existing damage detection approaches, namely, using the modern machine and deep learning methods. The findings of this study look very promising when applied to other types of cantilever structures, such as the poles that support the power transmission lines, antenna masts, chimneys, and wind turbines.},
  subject      = {Fahrleitung},
  language  = {en}
}
@article{AlkamLahmer,
  author    = {Alkam, Feras and Lahmer, Tom},
  title     = {Eigenfrequency-Based Bayesian Approach for Damage Identification in Catenary Poles},
  series = {Infrastructures},
  volume    = {2021},
  journal   = {Infrastructures},
  number    = {Volume 6, issue 4, article 57},
  publisher = {MDPI},
  address   = {Basel},
  doi       = {10.3390/infrastructures6040057},
  url       = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20210510-44256},
  pages     = {1 -- 19},
  abstract  = {This study proposes an efficient Bayesian, frequency-based damage identification approach to identify damages in cantilever structures with an acceptable error rate, even at high noise levels. The catenary poles of electric high-speed train systems were selected as a realistic case study to cover the objectives of this study. Compared to other frequency-based damage detection approaches described in the literature, the proposed approach is efficiently able to detect damages in cantilever structures to higher levels of damage detection, namely identifying both the damage location and severity using a low-cost structural health monitoring (SHM) system with a limited number of sensors; for example, accelerometers. The integration of Bayesian inference, as a stochastic framework, in the proposed approach, makes it possible to utilize the benefit of data fusion in merging the informative data from multiple damage features, which increases the quality and accuracy of the results. The findings provide the decision-maker with the information required to manage the maintenance, repair, or replacement procedures.},
  subject      = {Fahrleitung},
  language  = {en}
}
@misc{vonButler,
  type      = {Master Thesis},
  author    = {von Butler, Natalie},
  title     = {Scalarization Methods for Multi-Objective Structural Optimization},
  doi       = {10.25643/bauhaus-universitaet.4010},
  url       = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20191030-40106},
  school      = {Bauhaus-Universit{\"a}t Weimar},
  pages     = {178},
  abstract  = {Scalarization methods are a category of multiobjective optimization (MOO) methods. These methods allow the usage of conventional single objective optimization algorithms, as scalarization methods reformulate the MOO problem into a single objective optimization problem. The scalarization methods analysed within this thesis are the Weighted Sum (WS), the Epsilon-Constraint (EC), and the MinMax (MM) method. After explaining the approach of each method, the WS, EC and MM are applied, a-posteriori, to three different examples: to the Kursawe function; to the ten bar truss, a common benchmark problem in structural optimization; and to the metamodel of an aero engine exit module. The aim is to evaluate and compare the performance of each scalarization method that is examined within this thesis. The evaluation is conducted using performance metrics, such as the hypervolume and the generational distance, as well as using visual comparison. The application to the three examples gives insight into the advantages and disadvantages of each method, and provides further understanding of an adequate application of the methods concerning high dimensional optimization problems.},
  subject      = {Mehrkriterielle Optimierung},
  language  = {en}
}
@article{BenzTarabenLichtenheldetal.,
  author    = {Benz, Alexander and Taraben, Jakob and Lichtenheld, Thomas and Morgenthal, Guido and V{\"o}lker, Conrad},
  title     = {Thermisch-energetische Geb{\"a}udesimulation auf Basis eines Bauwerksinformationsmodells},
  series = {Bauphysik},
  journal   = {Bauphysik},
  number    = {40, Heft 2},
  doi       = {10.25643/bauhaus-universitaet.3835},
  url       = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20181221-38354},
  pages     = {61 -- 67},
  abstract  = {F{\"u}r eine Absch{\"a}tzung des Heizw{\"a}rmebedarfs von Geb{\"a}uden und Quartieren k{\"o}nnen thermisch-energetische Simulationen eingesetzt werden. Grundlage dieser Simulationen sind geometrische und physikalische Geb{\"a}udemodelle. Die Erstellung des geometrischen Modells erfolgt in der Regel auf Basis von Baupl{\"a}nen oder Vor-Ort-Begehungen, was mit einem großen Recherche- und Modellierungsaufwand verbunden ist. Sp{\"a}tere bauliche Ver{\"a}nderungen des Geb{\"a}udes m{\"u}ssen h{\"a}ufig manuell in das Modell eingearbeitet werden, was den Arbeitsaufwand zus{\"a}tzlich erh{\"o}ht. Das physikalische Modell stellt die Menge an Parametern und Randbedingungen dar, welche durch Materialeigenschaften, Lage und Umgebungs-einfl{\"u}sse gegeben sind. Die Verkn{\"u}pfung beider Modelle wird innerhalb der entsprechenden Simulations-software realisiert und ist meist nicht in andere Softwareprodukte {\"u}berf{\"u}hrbar. Mithilfe des Building Information Modeling (BIM) k{\"o}nnen Simulationsdaten sowohl konsistent gespeichert als auch {\"u}ber Schnittstellen mit entsprechenden Anwendungen ausgetauscht werden. Hierf{\"u}r wird eine Methode vorgestellt, die thermisch-energetische Simulationen auf Basis des standardisierten {\"U}bergabe-formats Industry Foundation Classes (IFC) inklusive anschließender Auswertungen erm{\"o}glicht. Dabei werden geometrische und physikalische Parameter direkt aus einem {\"u}ber den gesamten Lebenszyklus aktuellen Geb{\"a}udemodell extrahiert und an die Simulation {\"u}bergeben. Dies beschleunigt den Simulations-prozess hinsichtlich der Geb{\"a}udemodellierung und nach sp{\"a}teren baulichen Ver{\"a}nderungen. Die erarbeite-te Methode beruht hierbei auf einfachen Modellierungskonventionen bei der Erstellung des Bauwerksinformationsmodells und stellt eine vollst{\"a}ndige {\"U}bertragbarkeit der Eingangs- und Ausgangswerte sicher. Thermal building simulation based on BIM-models. Thermal energetic simulations are used for the estimation of the heating demand of buildings and districts. These simulations are based on building models containing geometrical and physical information. The creation of geometrical models is usually based on existing construction plans or in situ assessments which demand a comparatively big effort of investigation and modeling. Alterations, which are later applied to the structure, request manual changes of the related model, which increases the effort additionally. The physical model represents the total amount of parameters and boundary conditions that are influenced by material properties, location and environmental influences on the building. The link between both models is realized within the correspondent simulation soft-ware and is usually not transferable to other software products. By Applying Building Information Modeling (BIM) simulation data is stored consistently and an exchange to other software is enabled. Therefore, a method which allows a thermal energetic simulation based on the exchange format Industry Foundation Classes (IFC) including an evaluation is presented. All geometrical and physical information are extracted directly from the building model that is kept up-to-date during its life cycle and transferred to the simulation. This accelerates the simulation process regarding the geometrical modeling and adjustments after later changes of the building. The developed method is based on simple conventions for the creation of the building model and ensures a complete transfer of all simulation data.},
  subject      = {Building Information Modeling},
  language  = {de}
}
@article{BenzTarabenLichtenheldetal.,
  author    = {Benz, Alexander and Taraben, Jakob and Lichtenheld, Thomas and Morgenthal, Guido and V{\"o}lker, Conrad},
  title     = {Thermisch-energetische Geb{\"a}udesimulation auf Basis eines Bauwerksinformationsmodells},
  series = {Bauphysik},
  journal   = {Bauphysik},
  number    = {40, Heft 2},
  doi       = {10.25643/bauhaus-universitaet.3819},
  url       = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20181102-38190},
  pages     = {61 -- 67},
  abstract  = {F{\"u}r eine Absch{\"a}tzung des Heizw{\"a}rmebedarfs von Geb{\"a}uden und Quartieren k{\"o}nnen thermisch-energetische Simulationen eingesetzt werden. Grundlage dieser Simulationen sind geometrische und physikalische Geb{\"a}udemodelle. Die Erstellung des geometrischen Modells erfolgt in der Regel auf Basis von Baupl{\"a}nen oder Vor-Ort-Begehungen, was mit einem großen Recherche- und Modellierungsaufwand verbunden ist. Sp{\"a}tere bauliche Ver{\"a}nderungen des Geb{\"a}udes m{\"u}ssen h{\"a}ufig manuell in das Modell eingearbeitet werden, was den Arbeitsaufwand zus{\"a}tzlich erh{\"o}ht. Das physikalische Modell stellt die Menge an Parametern und Randbedingungen dar, welche durch Materialeigenschaften, Lage und Umgebungs-einfl{\"u}sse gegeben sind. Die Verkn{\"u}pfung beider Modelle wird innerhalb der entsprechenden Simulations-software realisiert und ist meist nicht in andere Softwareprodukte {\"u}berf{\"u}hrbar. Mithilfe des Building Information Modeling (BIM) k{\"o}nnen Simulationsdaten sowohl konsistent gespeichert als auch {\"u}ber Schnittstellen mit entsprechenden Anwendungen ausgetauscht werden. Hierf{\"u}r wird eine Methode vorgestellt, die thermisch-energetische Simulationen auf Basis des standardisierten {\"U}bergabe-formats Industry Foundation Classes (IFC) inklusive anschließender Auswertungen erm{\"o}glicht. Dabei werden geometrische und physikalische Parameter direkt aus einem {\"u}ber den gesamten Lebenszyklus aktuellen Geb{\"a}udemodell extrahiert und an die Simulation {\"u}bergeben. Dies beschleunigt den Simulations-prozess hinsichtlich der Geb{\"a}udemodellierung und nach sp{\"a}teren baulichen Ver{\"a}nderungen. Die erarbeite-te Methode beruht hierbei auf einfachen Modellierungskonventionen bei der Erstellung des Bauwerksinformationsmodells und stellt eine vollst{\"a}ndige {\"U}bertragbarkeit der Eingangs- und Ausgangswerte sicher. Thermal building simulation based on BIM-models. Thermal energetic simulations are used for the estimation of the heating demand of buildings and districts. These simulations are based on building models containing geometrical and physical information. The creation of geometrical models is usually based on existing construction plans or in situ assessments which demand a comparatively big effort of investigation and modeling. Alterations, which are later applied to the structure, request manual changes of the related model, which increases the effort additionally. The physical model represents the total amount of parameters and boundary conditions that are influenced by material properties, location and environmental influences on the building. The link between both models is realized within the correspondent simulation soft-ware and is usually not transferable to other software products. By Applying Building Information Modeling (BIM) simulation data is stored consistently and an exchange to other software is enabled. Therefore, a method which allows a thermal energetic simulation based on the exchange format Industry Foundation Classes (IFC) including an evaluation is presented. All geometrical and physical information are extracted directly from the building model that is kept up-to-date during its life cycle and transferred to the simulation. This accelerates the simulation process regarding the geometrical modeling and adjustments after later changes of the building. The developed method is based on simple conventions for the creation of the building model and ensures a complete transfer of all simulation data.},
  subject      = {Geb{\"a}udeh{\"u}lle},
  language  = {de}
}
@article{AchenbachLahmerMorgenthal,
  author    = {Achenbach, Marcus and Lahmer, Tom and Morgenthal, Guido},
  title     = {Identification of the thermal properties of concrete for the temperature calculation of concrete slabs and columns subjected to a standard fire—Methodology and proposal for simplified formulations},
  series = {Fire Safety Journal 87},
  journal   = {Fire Safety Journal 87},
  doi       = {10.1016/j.firesaf.2016.12.003},
  url       = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20170331-30929},
  pages     = {80 -- 86},
  abstract  = {The fire resistance of concrete members is controlled by the temperature distribution of the considered cross section. The thermal analysis can be performed with the advanced temperature dependent physical properties provided by 5EN6 1992-1-2. But the recalculation of laboratory tests on columns from 5TU6 Braunschweig shows, that there are deviations between the calculated and measured temperatures. Therefore it can be assumed, that the mathematical formulation of these thermal properties could be improved. A sensitivity analysis is performed to identify the governing parameters of the temperature calculation and a nonlinear optimization method is used to enhance the formulation of the thermal properties. The proposed simplified properties are partly validated by the recalculation of measured temperatures of concrete columns. These first results show, that the scatter of the differences from the calculated to the measured temperatures can be reduced by the proposed simple model for the thermal analysis of concrete.},
  subject      = {Sensitivit{\"a}tsanalyse},
  language  = {en}
}