@article{ZhangWangLahmeretal.,
  author    = {Zhang, Chao and Wang, Cuixia and Lahmer, Tom and He, Pengfei and Rabczuk, Timon},
  title     = {A dynamic XFEM formulation for crack identification},
  series = {International Journal of Mechanics and Materials in Design},
  journal   = {International Journal of Mechanics and Materials in Design},
  pages     = {427 -- 448},
  abstract  = {A dynamic XFEM formulation for crack identification},
  subject      = {Angewandte Mathematik},
  language  = {en}
}
@article{ZhangNanthakumarLahmeretal.,
  author    = {Zhang, Chao and Nanthakumar, S.S. and Lahmer, Tom and Rabczuk, Timon},
  title     = {Multiple cracks identification for piezoelectric structures},
  series = {International Journal of Fracture},
  journal   = {International Journal of Fracture},
  pages     = {1 -- 19},
  abstract  = {Multiple cracks identification for piezoelectric structures},
  subject      = {Angewandte Mathematik},
  language  = {en}
}
@article{VuBacSilaniLahmeretal.,
  author    = {Vu-Bac, N. and Silani, Mohammad and Lahmer, Tom and Zhuang, Xiaoying and Rabczuk, Timon},
  title     = {A unified framework for stochastic predictions of Young's modulus of clay/epoxy nanocomposites (PCNs)},
  series = {Computational Materials Science},
  journal   = {Computational Materials Science},
  pages     = {520 -- 535},
  abstract  = {A unified framework for stochastic predictions of Young's modulus of clay/epoxy nanocomposites (PCNs)},
  subject      = {Angewandte Mathematik},
  language  = {en}
}
@article{VuBacRafieeZhuangetal.,
  author    = {Vu-Bac, N. and Rafiee, Roham and Zhuang, Xiaoying and Lahmer, Tom and Rabczuk, Timon},
  title     = {Uncertainty quantification for multiscale modeling of polymer nanocomposites with correlated parameters},
  series = {Composites Part B: Engineering},
  journal   = {Composites Part B: Engineering},
  pages     = {446 -- 464},
  abstract  = {Uncertainty quantification for multiscale modeling of polymer nanocomposites with correlated parameters},
  subject      = {Angewandte Mathematik},
  language  = {en}
}
@article{VuBacLahmerZhuangetal.,
  author    = {Vu-Bac, N. and Lahmer, Tom and Zhuang, Xiaoying and Nguyen-Thoi, T. and Rabczuk, Timon},
  title     = {A software framework for probabilistic sensitivity analysis for computationally expensive models},
  series = {Advances in Engineering Software},
  journal   = {Advances in Engineering Software},
  pages     = {19 -- 31},
  abstract  = {A software framework for probabilistic sensitivity analysis for computationally expensive models},
  subject      = {Angewandte Mathematik},
  language  = {en}
}
@article{VuBacLahmerZhangetal.,
  author    = {Vu-Bac, N. and Lahmer, Tom and Zhang, Yancheng and Zhuang, Xiaoying and Rabczuk, Timon},
  title     = {Stochastic predictions of interfacial characteristic of polymeric nanocomposites (PNCs)},
  series = {Composites Part B Engineering},
  journal   = {Composites Part B Engineering},
  pages     = {80 -- 95},
  abstract  = {Stochastic predictions of interfacial characteristic of polymeric nanocomposites (PNCs)},
  subject      = {Angewandte Mathematik},
  language  = {en}
}
@article{VuBacLahmerKeiteletal.,
  author    = {Vu-Bac, N. and Lahmer, Tom and Keitel, Holger and Zhao, Jun-Hua and Zhuang, Xiaoying and Rabczuk, Timon},
  title     = {Stochastic predictions of bulk properties of amorphous polyethylene based on molecular dynamics simulations},
  series = {Mechanics of Materials},
  journal   = {Mechanics of Materials},
  pages     = {70 -- 84},
  abstract  = {Stochastic predictions of bulk properties of amorphous polyethylene based on molecular dynamics simulations},
  subject      = {Angewandte Mathematik},
  language  = {en}
}
@inproceedings{TanLahmerSiddappa,
  author    = {Tan, Fengjie and Lahmer, Tom and Siddappa, Manju Gyaraganahalll},
  title     = {SECTION OPTIMIZATION AND RELIABILITY ANALYSIS OF ARCH-TYPE DAMS INCLUDING COUPLED MECHANICAL-THERMAL AND HYDRAULIC FIELDS},
  series = {Digital Proceedings, International Conference on the Applications of Computer Science and Mathematics in Architecture and Civil Engineering : July 20 - 22 2015, Bauhaus-University Weimar},
  booktitle = {Digital Proceedings, International Conference on the Applications of Computer Science and Mathematics in Architecture and Civil Engineering : July 20 - 22 2015, Bauhaus-University Weimar},
  editor    = {G{\"u}rlebeck, Klaus and Lahmer, Tom},
  organization    = {Bauhaus-Universit{\"a}t Weimar},
  issn      = {1611-4086},
  doi       = {10.25643/bauhaus-universitaet.2821},
  url       = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20170314-28212},
  pages     = {8},
  abstract  = {From the design experiences of arch dams in the past, it has significant practical value to carry out the shape optimization of arch dams, which can fully make use of material characteristics and reduce the cost of constructions. Suitable variables need to be chosen to formulate the objective function, e.g. to minimize the total volume of the arch dam. Additionally a series of constraints are derived and a reasonable and convenient penalty function has been formed, which can easily enforce the characteristics of constraints and optimal design. For the optimization method, a Genetic Algorithm is adopted to perform a global search. Simultaneously, ANSYS is used to do the mechanical analysis under the coupling of thermal and hydraulic loads. One of the constraints of the newly designed dam is to fulfill requirements on the structural safety. Therefore, a reliability analysis is applied to offer a good decision supporting for matters concerning predictions of both safety and service life of the arch dam. By this, the key factors which would influence the stability and safety of arch dam significantly can be acquired, and supply a good way to take preventive measures to prolong ate the service life of an arch dam and enhances the safety of structure.},
  subject      = {Angewandte Informatik},
  language  = {en}
}
@unpublished{SteinerBourinetLahmer,
  author    = {Steiner, Maria and Bourinet, Jean-Marc and Lahmer, Tom},
  title     = {An adaptive sampling method for global sensitivity analysis based on least-squares support vector regression},
  doi       = {10.25643/BAUHAUS-UNIVERSITAET.3832},
  url       = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20181218-38320},
  pages     = {1 -- 33},
  abstract  = {In the field of engineering, surrogate models are commonly used for approximating the behavior of a physical phenomenon in order to reduce the computational costs. Generally, a surrogate model is created based on a set of training data, where a typical method for the statistical design is the Latin hypercube sampling (LHS). Even though a space filling distribution of the training data is reached, the sampling process takes no information on the underlying behavior of the physical phenomenon into account and new data cannot be sampled in the same distribution if the approximation quality is not sufficient. Therefore, in this study we present a novel adaptive sampling method based on a specific surrogate model, the least-squares support vector regresson. The adaptive sampling method generates training data based on the uncertainty in local prognosis capabilities of the surrogate model - areas of higher uncertainty require more sample data. The approach offers a cost efficient calculation due to the properties of the least-squares support vector regression. The opportunities of the adaptive sampling method are proven in comparison with the LHS on different analytical examples. Furthermore, the adaptive sampling method is applied to the calculation of global sensitivity values according to Sobol, where it shows faster convergence than the LHS method. With the applications in this paper it is shown that the presented adaptive sampling method improves the estimation of global sensitivity values, hence reducing the overall computational costs visibly.},
  subject      = {Approximation},
  language  = {en}
}
@article{SteinLahmerBock,
  author    = {Stein, Peter and Lahmer, Tom and Bock, Sebastian},
  title     = {Synthese und Analyse von gekoppelten Modellen im konstruktiven Ingenieurbau},
  series = {Bautechnik},
  journal   = {Bautechnik},
  pages     = {8 -- 11},
  abstract  = {Synthese und Analyse von gekoppelten Modellen im konstruktiven Ingenieurbau},
  subject      = {Angewandte Mathematik},
  language  = {de}
}
@article{SchmidtLahmer,
  author    = {Schmidt, Albrecht and Lahmer, Tom},
  title     = {Efficient domain decomposition based reliability analysis for polymorphic uncertain material parameters},
  series = {Proceedings in Applied Mathematics \& Mechanics},
  volume    = {2021},
  journal   = {Proceedings in Applied Mathematics \& Mechanics},
  number    = {Volume 21, issue 1},
  publisher = {Wiley-VHC},
  address   = {Weinheim},
  doi       = {10.1002/pamm.202100014},
  url       = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20220112-45563},
  pages     = {1 -- 4},
  abstract  = {Realistic uncertainty description incorporating aleatoric and epistemic uncertainties can be described within the framework of polymorphic uncertainty, which is computationally demanding. Utilizing a domain decomposition approach for random field based uncertainty models the proposed level-based sampling method can reduce these computational costs significantly and shows good agreement with a standard sampling technique. While 2-level configurations tend to get unstable with decreasing sampling density 3-level setups show encouraging results for the investigated reliability analysis of a structural unit square.},
  subject      = {Polymorphie},
  language  = {en}
}
@article{ReichertOlneyLahmer,
  author    = {Reichert, Ina and Olney, Peter and Lahmer, Tom},
  title     = {Combined approach for optimal sensor placement and experimental verification in the context of tower-like structures},
  series = {Journal of Civil Structural Health Monitoring},
  volume    = {2021},
  journal   = {Journal of Civil Structural Health Monitoring},
  number    = {volume 11},
  publisher = {Heidelberg},
  address   = {Springer},
  doi       = {10.1007/s13349-020-00448-7},
  url       = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20210804-44701},
  pages     = {223 -- 234},
  abstract  = {When it comes to monitoring of huge structures, main issues are limited time, high costs and how to deal with the big amount of data. In order to reduce and manage them, respectively, methods from the field of optimal design of experiments are useful and supportive. Having optimal experimental designs at hand before conducting any measurements is leading to a highly informative measurement concept, where the sensor positions are optimized according to minimal errors in the structures' models. For the reduction of computational time a combined approach using Fisher Information Matrix and mean-squared error in a two-step procedure is proposed under the consideration of different error types. The error descriptions contain random/aleatoric and systematic/epistemic portions. Applying this combined approach on a finite element model using artificial acceleration time measurement data with artificially added errors leads to the optimized sensor positions. These findings are compared to results from laboratory experiments on the modeled structure, which is a tower-like structure represented by a hollow pipe as the cantilever beam. Conclusively, the combined approach is leading to a sound experimental design that leads to a good estimate of the structure's behavior and model parameters without the need of preliminary measurements for model updating.},
  subject      = {Strukturmechanik},
  language  = {en}
}
@article{NguyenVinhBakarMsekhetal.,
  author    = {Nguyen-Vinh, H. and Bakar, I. and Msekh, Mohammed Abdulrazzak and Song, Jeong-Hoon and Muthu, Jacob and Zi, Goangseup and Le, P. and Bordas, St{\´e}phane Pierre Alain and Simpson, R. and Natarajan, S. and Lahmer, Tom and Rabczuk, Timon},
  title     = {Extended Finite Element Method for Dynamic Fracture of Piezo-Electric Materials},
  series = {Engineering Fracture Mechanics},
  journal   = {Engineering Fracture Mechanics},
  doi       = {10.1016/j.engfracmech.2012.04.025},
  pages     = {19 -- 31},
  abstract  = {We present an extended finite element formulation for dynamic fracture of piezo-electric materials. The method is developed in the context of linear elastic fracture mechanics. It is applied to mode I and mixed mode-fracture for quasi-steady cracks. An implicit time integration scheme is exploited. The results are compared to results obtained with the boundary element method and show excellent agreement.},
  subject      = {Angewandte Mathematik},
  language  = {en}
}
@article{NguyenTuanLahmerDatchevaetal.,
  author    = {Nguyen-Tuan, Long and Lahmer, Tom and Datcheva, Maria and Stoimenova, Eugenia and Schanz, Tom},
  title     = {A novel parameter identification approach for buffer elements involving complex coupled thermo-hydro-mechanical analyses},
  series = {Computers and Geotechnics},
  journal   = {Computers and Geotechnics},
  pages     = {23 -- 32},
  abstract  = {A novel parameter identification approach for buffer elements involving complex coupled thermo-hydro-mechanical analyses},
  subject      = {Angewandte Mathematik},
  language  = {en}
}
@inproceedings{NguyenTuanLahmerDatchevaetal.,
  author    = {Nguyen-Tuan, Long and Lahmer, Tom and Datcheva, Maria and Stoimenova, Eugenia and Schanz, Tom},
  title     = {PARAMETER IDENTIFICATION APPLYING IN COMPLEX THERMO-HYDRO-MECHANICAL PROBLEMS LIKE THE DESIGN OF BUFFER ELEMENTS},
  series = {Digital Proceedings, International Conference on the Applications of Computer Science and Mathematics in Architecture and Civil Engineering : July 20 - 22 2015, Bauhaus-University Weimar},
  booktitle = {Digital Proceedings, International Conference on the Applications of Computer Science and Mathematics in Architecture and Civil Engineering : July 20 - 22 2015, Bauhaus-University Weimar},
  editor    = {G{\"u}rlebeck, Klaus and Lahmer, Tom},
  organization    = {Bauhaus-Universit{\"a}t Weimar},
  issn      = {1611-4086},
  doi       = {10.25643/bauhaus-universitaet.2816},
  url       = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20170314-28162},
  pages     = {6},
  abstract  = {This study contributes to the identification of coupled THM constitutive model parameters via back analysis against information-rich experiments. A sampling based back analysis approach is proposed comprising both the model parameter identification and the assessment of the reliability of identified model parameters. The results obtained in the context of buffer elements indicate that sensitive parameter estimates generally obey the normal distribution. According to the sensitivity of the parameters and the probability distribution of the samples we can provide confidence intervals for the estimated parameters and thus allow a qualitative estimation on the identified parameters which are in future work used as inputs for prognosis computations of buffer elements. These elements play e.g. an important role in the design of nuclear waste repositories.},
  subject      = {Angewandte Informatik},
  language  = {en}
}
@article{NguyenTuanLahmerDatchevaetal.,
  author    = {Nguyen-Tuan, Long and Lahmer, Tom and Datcheva, Maria and Schanz, Tom},
  title     = {Global and local sensitivity analyses for coupled thermo-hydro-mechanical problems},
  series = {International Journal for Numerical and Analytical Methods in Geomechanics},
  journal   = {International Journal for Numerical and Analytical Methods in Geomechanics},
  abstract  = {Global and local sensitivity analyses for coupled thermo-hydro-mechanical problems},
  subject      = {Angewandte Mathematik},
  language  = {en}
}
@article{NguyenTuanKoenkeBettziecheetal.,
  author    = {Nguyen-Tuan, Long and K{\"o}nke, Carsten and Bettzieche, Volker and Lahmer, Tom},
  title     = {Numerical modeling and validation for 3D coupled-nonlinear thermo-hydro-mechanical problems in masonry dams},
  series = {Computers \& Structures},
  journal   = {Computers \& Structures},
  pages     = {143 -- 154},
  abstract  = {Numerical modeling and validation for 3D coupled-nonlinear thermo-hydro-mechanical problems in masonry dams},
  subject      = {Angewandte Mathematik},
  language  = {en}
}
@article{NanthakumarLahmerZhuangetal.,
  author    = {Nanthakumar, S.S. and Lahmer, Tom and Zhuang, Xiaoying and Zi, Goangseup and Rabczuk, Timon},
  title     = {Detection of material interfaces using a regularized level set method in piezoelectric structures},
  series = {Inverse Problems in Science and Engineering},
  journal   = {Inverse Problems in Science and Engineering},
  pages     = {153 -- 176},
  abstract  = {Detection of material interfaces using a regularized level set method in piezoelectric structures},
  subject      = {Angewandte Mathematik},
  language  = {en}
}
@article{NanthakumarLahmerZhuangetal.,
  author    = {Nanthakumar, S.S. and Lahmer, Tom and Zhuang, Xiaoying and Zi, Goangseup and Rabczuk, Timon},
  title     = {Detection of material interfaces using a regularized level set method in piezoelectric structures},
  series = {Inverse Problems in Science and Engineering},
  journal   = {Inverse Problems in Science and Engineering},
  abstract  = {Detection of material interfaces using a regularized level set method in piezoelectric structures},
  subject      = {Angewandte Mathematik},
  language  = {en}
}
@article{NanthakumarLahmerZhuangetal.,
  author    = {Nanthakumar, S.S. and Lahmer, Tom and Zhuang, Xiaoying and Park, Harold S. and Rabczuk, Timon},
  title     = {Topology optimization of piezoelectric nanostructures},
  series = {Journal of the Mechanics and Physics of Solids},
  journal   = {Journal of the Mechanics and Physics of Solids},
  pages     = {316 -- 335},
  abstract  = {Topology optimization of piezoelectric nanostructures},
  subject      = {Angewandte Mathematik},
  language  = {en}
}
@article{NanthakumarLahmerRabczuk,
  author    = {Nanthakumar, S.S. and Lahmer, Tom and Rabczuk, Timon},
  title     = {Detection of flaws in piezoelectric structures using extended FEM},
  series = {International Journal for Numerical Methods in Engineering},
  journal   = {International Journal for Numerical Methods in Engineering},
  pages     = {373 -- 389},
  abstract  = {Detection of flaws in piezoelectric structures using extended FEM},
  subject      = {Angewandte Mathematik},
  language  = {en}
}
@article{NanthakumarLahmerRabczuk,
  author    = {Nanthakumar, S.S. and Lahmer, Tom and Rabczuk, Timon},
  title     = {Detection of multiple flaws in piezoelectric structures using XFEM and level sets},
  series = {International Journal for Numerical Methods in Engineering},
  journal   = {International Journal for Numerical Methods in Engineering},
  pages     = {960},
  abstract  = {Detection of multiple flaws in piezoelectric structures using XFEM and level sets},
  subject      = {Angewandte Mathematik},
  language  = {en}
}
@article{NanthakumarLahmerRabczuk,
  author    = {Nanthakumar, S.S. and Lahmer, Tom and Rabczuk, Timon},
  title     = {Detection of multiple flaws in piezoelectric structures using XFEM and level sets},
  series = {Computer Methods in Applied Mechanics and Engineering},
  journal   = {Computer Methods in Applied Mechanics and Engineering},
  pages     = {98 -- 112},
  abstract  = {Detection of multiple flaws in piezoelectric structures using XFEM and level sets},
  subject      = {Angewandte Mathematik},
  language  = {en}
}
@article{MarzbanLahmer,
  author    = {Marzban, Samira and Lahmer, Tom},
  title     = {Conceptual implementation of the variance-based sensitivity analysis for the calculation of the first-order effects},
  series = {Journal of Statistical Theory and Practice},
  journal   = {Journal of Statistical Theory and Practice},
  pages     = {589 -- 611},
  abstract  = {Conceptual implementation of the variance-based sensitivity analysis for the calculation of the first-order effects},
  subject      = {Angewandte Mathematik},
  language  = {en}
}
@article{LizarazuHarirchianShaiketal.,
  author    = {Lizarazu, Jorge and Harirchian, Ehsan and Shaik, Umar Arif and Shareef, Mohammed and Antoni-Zdziobek, Annie and Lahmer, Tom},
  title     = {Application of machine learning-based algorithms to predict the stress-strain curves of additively manufactured mild steel out of its microstructural characteristics},
  series = {Results in Engineering},
  volume    = {2023},
  journal   = {Results in Engineering},
  number    = {Volume 20 (2023)},
  publisher = {Elsevier},
  address   = {Amsterdam},
  doi       = {10.1016/j.rineng.2023.101587},
  url       = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20231207-65028},
  pages     = {1 -- 12},
  abstract  = {The study presents a Machine Learning (ML)-based framework designed to forecast the stress-strain relationship of arc-direct energy deposited mild steel. Based on microstructural characteristics previously extracted using microscopy and X-ray diffraction, approximately 1000 new parameter sets are generated by applying the Latin Hypercube Sampling Method (LHSM). For each parameter set, a Representative Volume Element (RVE) is synthetically created via Voronoi Tessellation. Input raw data for ML-based algorithms comprises these parameter sets or RVE-images, while output raw data includes their corresponding stress-strain relationships calculated after a Finite Element (FE) procedure. Input data undergoes preprocessing involving standardization, feature selection, and image resizing. Similarly, the stress-strain curves, initially unsuitable for training traditional ML algorithms, are preprocessed using cubic splines and occasionally Principal Component Analysis (PCA). The later part of the study focuses on employing multiple ML algorithms, utilizing two main models. The first model predicts stress-strain curves based on microstructural parameters, while the second model does so solely from RVE images. The most accurate prediction yields a Root Mean Squared Error of around 5 MPa, approximately 1\% of the yield stress. This outcome suggests that ML models offer precise and efficient methods for characterizing dual-phase steels, establishing a framework for accurate results in material analysis.},
  subject      = {Maschinelles Lernen},
  language  = {en}
}
@article{LahmerNguyenTuanKoenkeetal.,
  author    = {Lahmer, Tom and Nguyen-Tuan, Long and K{\"o}nke, Carsten and Bettzieche, Volker},
  title     = {Thermo-hydro-mechanische 3-D-Simulation von Staumauern-Modellierung und Validierung},
  series = {WASSERWIRTSCHAFT},
  journal   = {WASSERWIRTSCHAFT},
  pages     = {27 -- 30},
  abstract  = {Thermo-hydro-mechanische 3-D-Simulation von Staumauern-Modellierung und Validierung},
  subject      = {Angewandte Mathematik},
  language  = {de}
}
@article{LahmerKoenkeBettzieche,
  author    = {Lahmer, Tom and K{\"o}nke, Carsten and Bettzieche, Volker},
  title     = {Optimale Positionierung von Messeinrichtungen an Staumauern zur Bauwerks{\"u}berwachung},
  series = {WASSERWIRTSCHAFT},
  journal   = {WASSERWIRTSCHAFT},
  pages     = {16 -- 16},
  abstract  = {Optimale Positionierung von Messeinrichtungen an Staumauern zur Bauwerks{\"u}berwachung},
  subject      = {Angewandte Mathematik},
  language  = {de}
}
@article{LahmerKoenkeBettzieche,
  author    = {Lahmer, Tom and K{\"o}nke, Carsten and Bettzieche, Volker},
  title     = {Optimal positioning of sensors for the monitoring of water dams},
  series = {WASSERWIRTSCHAFT},
  journal   = {WASSERWIRTSCHAFT},
  pages     = {16 -- 19},
  abstract  = {Optimal positioning of sensors for the monitoring of water dams},
  subject      = {Angewandte Mathematik},
  language  = {de}
}
@article{LahmerKnabeNikullaetal.,
  author    = {Lahmer, Tom and Knabe, Tina and Nikulla, Susanne and Reuter, Markus},
  title     = {Bewertungsmethoden f{\"u}r Modelle des konstruktiven Ingenieurbaus},
  series = {Bautechnik},
  journal   = {Bautechnik},
  pages     = {60 -- 64},
  abstract  = {Bewertungsmethoden f{\"u}r Modelle des konstruktiven Ingenieurbaus},
  subject      = {Angewandte Mathematik},
  language  = {de}
}
@article{LahmerKaltenbacherKaltenbacheretal.,
  author    = {Lahmer, Tom and Kaltenbacher, Manfred and Kaltenbacher, Barbara and Lerch, Reinhard and Leder, Erich},
  title     = {Fem-based determination of real and complex elastic, dielectric, and piezoelectric moduli in piezoceramic materials},
  series = {IEEE transactions on ultrasonics, ferroelectrics, and frequency control},
  journal   = {IEEE transactions on ultrasonics, ferroelectrics, and frequency control},
  doi       = {10.25643/bauhaus-universitaet.3594},
  abstract  = {Fem-based determination of real and complex elastic, dielectric, and piezoelectric moduli in piezoceramic materials.},
  subject      = {Angewandte Mathematik},
  language  = {en}
}
@article{LahmerKaltenbacherSchulz,
  author    = {Lahmer, Tom and Kaltenbacher, Barbara and Schulz, V.},
  title     = {Optimal measurement selection for piezoelectric material tensor identification},
  series = {Inverse Problems in Science and Engineering},
  journal   = {Inverse Problems in Science and Engineering},
  doi       = {10.25643/bauhaus-universitaet.3593},
  pages     = {369 -- 387},
  abstract  = {Optimal measurement selection for piezoelectric material tensor identification.},
  subject      = {Angewandte Mathematik},
  language  = {en}
}
@article{LahmerIlgLerch,
  author    = {Lahmer, Tom and Ilg, J. and Lerch, Reinhard},
  title     = {Variance-based sensitivity analyses of piezoelectric models},
  series = {Computer Modeling in Engineering \& Sciences},
  journal   = {Computer Modeling in Engineering \& Sciences},
  pages     = {105 -- 126},
  abstract  = {Variance-based sensitivity analyses of piezoelectric models},
  subject      = {Angewandte Mathematik},
  language  = {en}
}
@inproceedings{LahmerGhorashi,
  author    = {Lahmer, Tom and Ghorashi, Seyed Shahram},
  title     = {XFEM-BASED CRACK IDENTIFICATION APPLYING REGULARIZING METHODS IN A MULTILEVEL APPROACH},
  series = {Digital Proceedings, International Conference on the Applications of Computer Science and Mathematics in Architecture and Civil Engineering : July 04 - 06 2012, Bauhaus-University Weimar},
  booktitle = {Digital Proceedings, International Conference on the Applications of Computer Science and Mathematics in Architecture and Civil Engineering : July 04 - 06 2012, Bauhaus-University Weimar},
  editor    = {G{\"u}rlebeck, Klaus and Lahmer, Tom and Werner, Frank},
  organization    = {Bauhaus-Universit{\"a}t Weimar},
  issn      = {1611-4086},
  doi       = {10.25643/bauhaus-universitaet.2771},
  url       = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20170314-27717},
  pages     = {9},
  abstract  = {Many structures in different engineering applications suffer from cracking. In order to make reliable prognosis about the serviceability of those structures it is of utmost importance to identify cracks as precisely as possible by non-destructive testing. A novel approach (XIGA), which combines the Isogeometric Analysis (IGA) and the Extended Finite Element Method (XFEM) is used for the forward problem, namely the analysis of a cracked material, see [1]. Applying the NURBS (Non-Uniform Rational B-Spline) based approach from IGA together with the XFEM allows to describe effectively arbitrarily shaped cracks and avoids the necessity of remeshing during the crack identification problem. We want to exploit these advantages for the inverse problem of detecting existing cracks by non-destructive testing, see e.g. [2]. The quality of the reconstructed cracks however depends on two major issues, namely the quality of the measured data (measurement error) and the discretization of the crack model. The first one will be taken into account by applying regularizing methods with a posteriori stopping criteria. The second one is critical in the sense that too few degrees of freedom, i.e. the number of control points of the NURBS, do not allow for a precise description of the crack. An increased number of control points, however, increases the number of unknowns in the inverse analysis and intensifies the ill-posedness. The trade-off between accuracy and stability is aimed to be found by applying an inverse multilevel algorithm [3, 4] where the identification is started with short knot vectors which successively will be enlarged during the identification process.},
  subject      = {Angewandte Informatik},
  language  = {en}
}
@article{LahmerBockHildebrandetal.,
  author    = {Lahmer, Tom and Bock, Sebastian and Hildebrand, J{\"o}rg and G{\"u}rlebeck, Klaus},
  title     = {Non-destructive identification of residual stresses in steel under thermal loadings},
  series = {Inverse Problems in Science and Engineering},
  journal   = {Inverse Problems in Science and Engineering},
  pages     = {1 -- 17},
  abstract  = {Non-destructive identification of residual stresses in steel under thermal loadings},
  subject      = {Angewandte Mathematik},
  language  = {en}
}
@inproceedings{Lahmer,
  author    = {Lahmer, Tom},
  title     = {HYDRO-MECHANICAL COUPLED FIELD SYSTEM IDENTIFICATION - APPLICATION TO WATER RESERVOIRS},
  editor    = {G{\"u}rlebeck, Klaus and K{\"o}nke, Carsten},
  organization    = {Bauhaus-Universit{\"a}t Weimar},
  issn      = {1611-4086},
  doi       = {10.25643/bauhaus-universitaet.2865},
  url       = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20170314-28650},
  pages     = {14},
  abstract  = {In this paper we present an inverse method which is capable of identifying system components in a hydro-mechanically coupled system, i.e. for fluid flow in porous media. As an example we regard water dams that were constructed more than hundred years ago but which are still in use. Over the time ageing processes have changed the condition of these dams. Within the dams fissures might have grown. The proposed method is designed to locate these fissures out of combined mechanical and hydraulic measurements. In a numerical example the fissures or damaged zones are described by a smeared crack model. The task is now to identify simultaneously the spatial distribution of Young's modulus and the hydraulic permeability due to the fact, that in regions where damages are present, the mechanical stiffness of the system is reduced and the permeability increased. The inversion is shown to be an ill-posed problem. As a consequence regularizing methods have to be applied, where the nonlinear Landweber method (a gradient type method combined with a discrepancy principle) has proven to be an efficient choice.},
  subject      = {Angewandte Informatik},
  language  = {en}
}
@article{Lahmer,
  author    = {Lahmer, Tom},
  title     = {Optimal experimental design for nonlinear ill-posed problems applied to gravity dams},
  series = {Inverse Problems},
  journal   = {Inverse Problems},
  abstract  = {Optimal experimental design for nonlinear ill-posed problems applied to gravity dams},
  subject      = {Angewandte Mathematik},
  language  = {en}
}
@article{Lahmer,
  author    = {Lahmer, Tom},
  title     = {Modified Landweber iterations in a multilevel algorithm applied to inverse problems in piezoelectricity},
  series = {Journal of Inverse and Ill-posed Problems},
  journal   = {Journal of Inverse and Ill-posed Problems},
  pages     = {585 -- 593},
  abstract  = {Modified Landweber iterations in a multilevel algorithm applied to inverse problems in piezoelectricity},
  subject      = {Angewandte Mathematik},
  language  = {en}
}
@article{Lahmer,
  author    = {Lahmer, Tom},
  title     = {FEM-Based determination of real and complex elastic, dielectric, and piezoelectric moduli in piezoceramic materials},
  series = {IEEE Transactions on Ultrasonics, Ferroelectrics, and Frequency Control},
  journal   = {IEEE Transactions on Ultrasonics, Ferroelectrics, and Frequency Control},
  doi       = {10.25643/bauhaus-universitaet.3608},
  url       = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20171030-36083},
  abstract  = {We propose an enhanced iterative scheme for the precise reconstruction of piezoelectric material parameters from electric impedance and mechanical displacement measurements. It is based on finite-element simulations of the full three-dimensional piezoelectric equations, combined with an inexact Newton or nonlinear Landweber iterative inversion scheme. We apply our method to two piezoelectric materials and test its performance. For the first material, the manufacturer provides a full data set; for the second one, no material data set is available. For both cases, our inverse scheme, using electric impedance measurements as input data, performs well.},
  subject      = {Finite-Elemente-Methode},
  language  = {en}
}
@article{Lahmer,
  author    = {Lahmer, Tom},
  title     = {Crack identification in hydro-mechanical systems with applications to gravity water dams},
  series = {Inverse Problems in Science and Engineering},
  journal   = {Inverse Problems in Science and Engineering},
  pages     = {1083 -- 1101},
  abstract  = {Crack identification in hydro-mechanical systems with applications to gravity water dams},
  subject      = {Angewandte Mathematik},
  language  = {en}
}
@article{KumariHarirchianLahmeretal.,
  author    = {Kumari, Vandana and Harirchian, Ehsan and Lahmer, Tom and Rasulzade, Shahla},
  title     = {Evaluation of Machine Learning and Web-Based Process for Damage Score Estimation of Existing Buildings},
  series = {Buildings},
  volume    = {2022},
  journal   = {Buildings},
  number    = {Volume 12, issue 5, article 578},
  publisher = {MDPI},
  address   = {Basel},
  doi       = {10.3390/buildings12050578},
  url       = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20220509-46387},
  pages     = {1 -- 23},
  abstract  = {The seismic vulnerability assessment of existing reinforced concrete (RC) buildings is a significant source of disaster mitigation plans and rescue services. Different countries evolved various Rapid Visual Screening (RVS) techniques and methodologies to deal with the devastating consequences of earthquakes on the structural characteristics of buildings and human casualties. Artificial intelligence (AI) methods, such as machine learning (ML) algorithm-based methods, are increasingly used in various scientific and technical applications. The investigation toward using these techniques in civil engineering applications has shown encouraging results and reduced human intervention, including uncertainties and biased judgment. In this study, several known non-parametric algorithms are investigated toward RVS using a dataset employing different earthquakes. Moreover, the methodology encourages the possibility of examining the buildings' vulnerability based on the factors related to the buildings' importance and exposure. In addition, a web-based application built on Django is introduced. The interface is designed with the idea to ease the seismic vulnerability investigation in real-time. The concept was validated using two case studies, and the achieved results showed the proposed approach's potential efficiency},
  subject      = {Maschinelles Lernen},
  language  = {en}
}
@article{KnabeDatchevaLahmeretal.,
  author    = {Knabe, Tina and Datcheva, Maria and Lahmer, Tom and Cotecchia, F. and Schanz, Tom},
  title     = {Identification of constitutive parameters of soil using an optimization strategy and statistical analysis},
  series = {Computers and Geotechnics},
  journal   = {Computers and Geotechnics},
  pages     = {143 -- 157},
  abstract  = {Identification of constitutive parameters of soil using an optimization strategy and statistical analysis},
  subject      = {Angewandte Mathematik},
  language  = {en}
}
@article{KeitelKarakiLahmeretal.,
  author    = {Keitel, Holger and Karaki, Ghada and Lahmer, Tom and Nikulla, Susanne and Zabel, Volkmar},
  title     = {Evaluation of coupled partial models in structural engineering using graph theory and sensitivity analysis},
  series = {Engineering structures},
  journal   = {Engineering structures},
  pages     = {3726 -- 3736},
  abstract  = {Evaluation of coupled partial models in structural engineering using graph theory and sensitivity analysis},
  subject      = {Angewandte Mathematik},
  language  = {en}
}
@article{KaltenbacherLahmerMohretal.,
  author    = {Kaltenbacher, Barbara and Lahmer, Tom and Mohr, Marcus and Kaltenbacher, Manfred},
  title     = {PDE based determination of piezoelectric material tensors},
  series = {European Journal of Applied Mathematics},
  journal   = {European Journal of Applied Mathematics},
  doi       = {10.25643/bauhaus-universitaet.3595},
  pages     = {383 -- 416},
  abstract  = {PDE based determination of piezoelectric material tensors.},
  subject      = {Angewandte Mathematik},
  language  = {en}
}
@inproceedings{JaouadiLahmer,
  author    = {Jaouadi, Zouhour and Lahmer, Tom},
  title     = {Topology optimization of structures subjected to multiple load cases by introducing the Epsilon constraint method},
  series = {Digital Proceedings, International Conference on the Applications of Computer Science and Mathematics in Architecture and Civil Engineering : July 20 - 22 2015, Bauhaus-University Weimar},
  booktitle = {Digital Proceedings, International Conference on the Applications of Computer Science and Mathematics in Architecture and Civil Engineering : July 20 - 22 2015, Bauhaus-University Weimar},
  editor    = {G{\"u}rlebeck, Klaus and Lahmer, Tom},
  organization    = {Bauhaus-Universit{\"a}t Weimar},
  issn      = {1611-4086},
  doi       = {10.25643/bauhaus-universitaet.2804},
  url       = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20170314-28042},
  pages     = {7},
  abstract  = {A topology optimization method has been developed for structures subjected to multiple load cases (Example of a bridge pier subjected to wind loads, traffic, superstructure...). We formulate the problem as a multi-criterial optimization problem, where the compliance is computed for each load case. Then, the Epsilon constraint method (method proposed by Chankong and Haimes, 1971) is adapted. The strategy of this method is based on the concept of minimizing the maximum compliance resulting from the critical load case while the other remaining compliances are considered in the constraints. In each iteration, the compliances of all load cases are computed and only the maximum one is minimized. The topology optimization process is switching from one load to another according to the variation of the resulting compliance. In this work we will motivate and explain the proposed methodology and provide some numerical examples.},
  subject      = {Angewandte Informatik},
  language  = {en}
}
@article{IlyaniAkmarLahmerBordasetal.,
  author    = {Ilyani Akmar, A.B. and Lahmer, Tom and Bordas, St{\´e}phane Pierre Alain and Beex, L.A.A. and Rabczuk, Timon},
  title     = {Uncertainty quantification of dry woven fabrics: A sensitivity analysis on material properties},
  series = {Composite Structures},
  journal   = {Composite Structures},
  doi       = {10.1016/j.compstruct.2014.04.014},
  pages     = {1 -- 17},
  abstract  = {Uncertainty quantification of dry woven fabrics: A sensitivity analysis on material properties},
  subject      = {Angewandte Mathematik},
  language  = {en}
}
@article{HauckLahmerKaltenbacher,
  author    = {Hauck, A. and Lahmer, Tom and Kaltenbacher, Manfred},
  title     = {Enhanced homogenization technique for magnetomechanical systems using the generalized finite element method},
  series = {COMPEL: The international journal for computation and mathematics in electrical and electronic engineering},
  journal   = {COMPEL: The international journal for computation and mathematics in electrical and electronic engineering},
  pages     = {935 -- 947},
  abstract  = {Enhanced homogenization technique for magnetomechanical systems using the generalized finite element method},
  subject      = {Angewandte Mathematik},
  language  = {en}
}
@inproceedings{HartmannSmarslyLahmer,
  author    = {Hartmann, Veronika and Smarsly, Kay and Lahmer, Tom},
  title     = {ROBUST SCHEDULING IN CONSTRUCTION ENGINEERING},
  series = {Digital Proceedings, International Conference on the Applications of Computer Science and Mathematics in Architecture and Civil Engineering : July 20 - 22 2015, Bauhaus-University Weimar},
  booktitle = {Digital Proceedings, International Conference on the Applications of Computer Science and Mathematics in Architecture and Civil Engineering : July 20 - 22 2015, Bauhaus-University Weimar},
  editor    = {G{\"u}rlebeck, Klaus and Lahmer, Tom},
  organization    = {Bauhaus-Universit{\"a}t Weimar},
  issn      = {1611-4086},
  doi       = {10.25643/bauhaus-universitaet.2799},
  url       = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20170314-27994},
  pages     = {5},
  abstract  = {In construction engineering, a schedule's input data, which is usually not exactly known in the planning phase, is considered deterministic when generating the schedule. As a result, construction schedules become unreliable and deadlines are often not met. While the optimization of construction schedules with respect to costs and makespan has been a matter of research in the past decades, the optimization of the robustness of construction schedules has received little attention. In this paper, the effects of uncertainties inherent to the input data of construction schedules are discussed. Possibilities are investigated to improve the reliability of construction schedules by considering alternative processes for certain tasks and by identifying the combination of processes generating the most robust schedule with respect to the makespan of a construction project.},
  subject      = {Angewandte Informatik},
  language  = {en}
}
@article{HarirchianLahmerRasulzade,
  author    = {Harirchian, Ehsan and Lahmer, Tom and Rasulzade, Shahla},
  title     = {Earthquake Hazard Safety Assessment of Existing Buildings Using Optimized Multi-Layer Perceptron Neural Network},
  series = {Energies},
  volume    = {2020},
  journal   = {Energies},
  number    = {Volume 13, Issue 8, 2060},
  publisher = {MDPI},
  address   = {Basel},
  doi       = {10.3390/en13082060},
  url       = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20200504-41575},
  pages     = {16},
  abstract  = {The latest earthquakes have proven that several existing buildings, particularly in developing countries, are not secured from damages of earthquake. A variety of statistical and machine-learning approaches have been proposed to identify vulnerable buildings for the prioritization of retrofitting. The present work aims to investigate earthquake susceptibility through the combination of six building performance variables that can be used to obtain an optimal prediction of the damage state of reinforced concrete buildings using artificial neural network (ANN). In this regard, a multi-layer perceptron network is trained and optimized using a database of 484 damaged buildings from the D{\"u}zce earthquake in Turkey. The results demonstrate the feasibility and effectiveness of the selected ANN approach to classify concrete structural damage that can be used as a preliminary assessment technique to identify vulnerable buildings in disaster risk-management programs.},
  subject      = {Erdbeben},
  language  = {en}
}
@article{HarirchianLahmerKumarietal.,
  author    = {Harirchian, Ehsan and Lahmer, Tom and Kumari, Vandana and Jadhav, Kirti},
  title     = {Application of Support Vector Machine Modeling for the Rapid Seismic Hazard Safety Evaluation of Existing Buildings},
  series = {Energies},
  volume    = {2020},
  journal   = {Energies},
  number    = {volume 13, issue 13, 3340},
  publisher = {MDPI},
  address   = {Basel},
  doi       = {10.3390/en13133340},
  url       = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20200707-41915},
  pages     = {15},
  abstract  = {The economic losses from earthquakes tend to hit the national economy considerably; therefore, models that are capable of estimating the vulnerability and losses of future earthquakes are highly consequential for emergency planners with the purpose of risk mitigation. This demands a mass prioritization filtering of structures to identify vulnerable buildings for retrofitting purposes. The application of advanced structural analysis on each building to study the earthquake response is impractical due to complex calculations, long computational time, and exorbitant cost. This exhibits the need for a fast, reliable, and rapid method, commonly known as Rapid Visual Screening (RVS). The method serves as a preliminary screening platform, using an optimum number of seismic parameters of the structure and predefined output damage states. In this study, the efficacy of the Machine Learning (ML) application in damage prediction through a Support Vector Machine (SVM) model as the damage classification technique has been investigated. The developed model was trained and examined based on damage data from the 1999 D{\"u}zce Earthquake in Turkey, where the building's data consists of 22 performance modifiers that have been implemented with supervised machine learning.},
  subject      = {Erdbeben},
  language  = {en}
}
@article{HarirchianLahmerBuddhirajuetal.,
  author    = {Harirchian, Ehsan and Lahmer, Tom and Buddhiraju, Sreekanth and Mohammad, Kifaytullah and Mosavi, Amir},
  title     = {Earthquake Safety Assessment of Buildings through Rapid Visual Screening},
  series = {Buildings},
  volume    = {2020},
  journal   = {Buildings},
  number    = {Volume 10, Issue 3},
  publisher = {MDPI},
  doi       = {10.3390/buildings10030051},
  url       = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20200331-41153},
  pages     = {15},
  abstract  = {Earthquake is among the most devastating natural disasters causing severe economical, environmental, and social destruction. Earthquake safety assessment and building hazard monitoring can highly contribute to urban sustainability through identification and insight into optimum materials and structures. While the vulnerability of structures mainly depends on the structural resistance, the safety assessment of buildings can be highly challenging. In this paper, we consider the Rapid Visual Screening (RVS) method, which is a qualitative procedure for estimating structural scores for buildings suitable for medium- to high-seismic cases. This paper presents an overview of the common RVS methods, i.e., FEMA P-154, IITK-GGSDMA, and EMPI. To examine the accuracy and validation, a practical comparison is performed between their assessment and observed damage of reinforced concrete buildings from a street survey in the Bing{\"o}l region, Turkey, after the 1 May 2003 earthquake. The results demonstrate that the application of RVS methods for preliminary damage estimation is a vital tool. Furthermore, the comparative analysis showed that FEMA P-154 creates an assessment that overestimates damage states and is not economically viable, while EMPI and IITK-GGSDMA provide more accurate and practical estimation, respectively.},
  subject      = {Maschinelles Lernen},
  language  = {en}
}