Dokument-ID Dokumenttyp Verfasser/Autoren Herausgeber Haupttitel Abstract Auflage Verlagsort Verlag Erscheinungsjahr Seitenzahl Schriftenreihe Titel Schriftenreihe Bandzahl ISBN Quelle der Hochschulschrift Konferenzname Quelle:Titel Quelle:Jahrgang Quelle:Heftnummer Quelle:Erste Seite Quelle:Letzte Seite URN DOI Abteilungen OPUS4-3348 Wissenschaftlicher Artikel Zhuang, Xiaoying; Huang, Runqiu; Rabczuk, Timon; Liang, C. A coupled thermo-hydro-mechanical model of jointed hard rock for compressed air energy storage A coupled thermo-hydro-mechanical model of jointed hard rock for compressed air energy storage Mathematical Problems in Engineering Institut für Strukturmechanik (ISM) OPUS4-3172 Wissenschaftlicher Artikel Zhuang, Xiaoying; Huang, Runqiu; Liang, Chao; Rabczuk, Timon A coupled thermo-hydro-mechanical model of jointed hard rock for compressed air energy storage Renewable energy resources such as wind and solar are intermittent, which causes instability when being connected to utility grid of electricity. Compressed air energy storage (CAES) provides an economic and technical viable solution to this problem by utilizing subsurface rock cavern to store the electricity generated by renewable energy in the form of compressed air. Though CAES has been used for over three decades, it is only restricted to salt rock or aquifers for air tightness reason. In this paper, the technical feasibility of utilizing hard rock for CAES is investigated by using a coupled thermo-hydro-mechanical (THM) modelling of nonisothermal gas flow. Governing equations are derived from the rules of energy balance, mass balance, and static equilibrium. Cyclic volumetric mass source and heat source models are applied to simulate the gas injection and production. Evaluation is carried out for intact rock and rock with discrete crack, respectively. In both cases, the heat and pressure losses using air mass control and supplementary air injection are compared. Mathematical Problems in Engineering urn:nbn:de:gbv:wim2-20170428-31726 10.1155/2014/179169 Institut für Strukturmechanik (ISM) OPUS4-3330 Wissenschaftlicher Artikel Zhang, Yancheng; Zhuang, Xiaoying; Muthu, Jacob; Mabrouki, Tarek; Fontaine, Michaël; Gong, Yadong; Rabczuk, Timon Load transfer of graphene/carbon nanotube/polyethylene hybrid nanocomposite by molecular dynamics simulation Load transfer of graphene/carbon nanotube/polyethylene hybrid nanocomposite by molecular dynamics simulation 6 Composites Part B Engineering 27 33 Institut für Strukturmechanik (ISM) OPUS4-3291 Wissenschaftlicher Artikel Vu-Bac, N.; Silani, Mohammad; Lahmer, Tom; Zhuang, Xiaoying; Rabczuk, Timon A unified framework for stochastic predictions of Young's modulus of clay/epoxy nanocomposites (PCNs) A unified framework for stochastic predictions of Young's modulus of clay/epoxy nanocomposites (PCNs) 15 Computational Materials Science 520 535 Institut für Strukturmechanik (ISM) OPUS4-3581 Wissenschaftlicher Artikel Vu-Bac, N.; Rafiee, Roham; Zhuang, Xiaoying; Lahmer, Tom; Rabczuk, Timon Uncertainty quantification for multiscale modeling of polymer nanocomposites with correlated parameters Uncertainty quantification for multiscale modeling of polymer nanocomposites with correlated parameters 18 Composites Part B: Engineering 446 464 Institut für Strukturmechanik (ISM) OPUS4-3167 Wissenschaftlicher Artikel Vu-Bac, N.; Nguyen-Xuan, Hung; Chen, Lei; Lee, C.K.; Zi, Goangseup; Zhuang, Xiaoying; Liu, G.R.; Rabczuk, Timon A phantom-node method with edge-based strain smoothing for linear elastic fracture mechanics This paper presents a novel numerical procedure based on the combination of an edge-based smoothed finite element (ES-FEM) with a phantom-node method for 2D linear elastic fracture mechanics. In the standard phantom-node method, the cracks are formulated by adding phantom nodes, and the cracked element is replaced by two new superimposed elements. This approach is quite simple to implement into existing explicit finite element programs. The shape functions associated with discontinuous elements are similar to those of the standard finite elements, which leads to certain simplification with implementing in the existing codes. The phantom-node method allows modeling discontinuities at an arbitrary location in the mesh. The ES-FEM model owns a close-to-exact stiffness that is much softer than lower-order finite element methods (FEM). Taking advantage of both the ES-FEM and the phantom-node method, we introduce an edge-based strain smoothing technique for the phantom-node method. Numerical results show that the proposed method achieves high accuracy compared with the extended finite element method (XFEM) and other reference solutions. Journal of Applied Mathematics urn:nbn:de:gbv:wim2-20170426-31676 10.1155/2013/978026 Institut für Strukturmechanik (ISM) OPUS4-3578 Wissenschaftlicher Artikel Vu-Bac, N.; Lahmer, Tom; Zhuang, Xiaoying; Nguyen-Thoi, T.; Rabczuk, Timon A software framework for probabilistic sensitivity analysis for computationally expensive models A software framework for probabilistic sensitivity analysis for computationally expensive models 12 Advances in Engineering Software 19 31 Institut für Strukturmechanik (ISM) OPUS4-3332 Wissenschaftlicher Artikel Vu-Bac, N.; Lahmer, Tom; Zhang, Yancheng; Zhuang, Xiaoying; Rabczuk, Timon Stochastic predictions of interfacial characteristic of polymeric nanocomposites (PNCs) Stochastic predictions of interfacial characteristic of polymeric nanocomposites (PNCs) 15 Composites Part B Engineering 80 95 Institut für Strukturmechanik (ISM) OPUS4-3343 Wissenschaftlicher Artikel Vu-Bac, N.; Lahmer, Tom; Keitel, Holger; Zhao, Jun-Hua; Zhuang, Xiaoying; Rabczuk, Timon Stochastic predictions of bulk properties of amorphous polyethylene based on molecular dynamics simulations Stochastic predictions of bulk properties of amorphous polyethylene based on molecular dynamics simulations 14 Mechanics of Materials 70 84 Institut für Strukturmechanik (ISM) OPUS4-4538 Wissenschaftlicher Artikel Ren, Huilong; Zhuang, Xiaoying; Oterkus, Erkan; Zhu, Hehua; Rabczuk, Timon Nonlocal strong forms of thin plate, gradient elasticity, magneto-electro-elasticity and phase-field fracture by nonlocal operator method The derivation of nonlocal strong forms for many physical problems remains cumbersome in traditional methods. In this paper, we apply the variational principle/weighted residual method based on nonlocal operator method for the derivation of nonlocal forms for elasticity, thin plate, gradient elasticity, electro-magneto-elasticity and phase-field fracture method. The nonlocal governing equations are expressed as an integral form on support and dual-support. The first example shows that the nonlocal elasticity has the same form as dual-horizon non-ordinary state-based peridynamics. The derivation is simple and general and it can convert efficiently many local physical models into their corresponding nonlocal forms. In addition, a criterion based on the instability of the nonlocal gradient is proposed for the fracture modelling in linear elasticity. Several numerical examples are presented to validate nonlocal elasticity and the nonlocal thin plate. 1-22 Engineering with Computers 2021 1 22 urn:nbn:de:gbv:wim2-20211207-45388 10.1007/s00366-021-01502-8 Institut für Strukturmechanik (ISM) OPUS4-6365 Wissenschaftlicher Artikel Rabczuk, Timon; Zhuang, Xiaoying; Oterkus, Erkan Editorial: Computational modeling based on nonlocal theory Nonlocal theories concern the interaction of objects, which are separated in space. Classical examples are Coulomb's law or Newton's law of universal gravitation. They had signficiant impact in physics and engineering. One classical application in mechanics is the failure of quasi-brittle materials. While local models lead to an ill-posed boundary value problem and associated mesh dependent results, nonlocal models guarantee the well-posedness and are furthermore relatively easy to implement into commercial computational software. London Springer 1 Engineering with Computers 2023 Volume 39, issue 3 urn:nbn:de:gbv:wim2-20230517-63658 https://doi.org/10.1007/s00366-022-01775-7 Professur Modellierung und Simulation - Mechanik OPUS4-4583 Wissenschaftlicher Artikel Rabczuk, Timon; Guo, Hongwei; Zhuang, Xiaoying; Chen, Pengwan; Alajlan, Naif Stochastic deep collocation method based on neural architecture search and transfer learning for heterogeneous porous media We present a stochastic deep collocation method (DCM) based on neural architecture search (NAS) and transfer learning for heterogeneous porous media. We first carry out a sensitivity analysis to determine the key hyper-parameters of the network to reduce the search space and subsequently employ hyper-parameter optimization to finally obtain the parameter values. The presented NAS based DCM also saves the weights and biases of the most favorable architectures, which is then used in the fine-tuning process. We also employ transfer learning techniques to drastically reduce the computational cost. The presented DCM is then applied to the stochastic analysis of heterogeneous porous material. Therefore, a three dimensional stochastic flow model is built providing a benchmark to the simulation of groundwater flow in highly heterogeneous aquifers. The performance of the presented NAS based DCM is verified in different dimensions using the method of manufactured solutions. We show that it significantly outperforms finite difference methods in both accuracy and computational cost. London Springer 26 Engineering with Computers 2022 1 26 urn:nbn:de:gbv:wim2-20220209-45835 10.1007/s00366-021-01586-2 Institut für Strukturmechanik (ISM) OPUS4-4475 Wissenschaftlicher Artikel Noori, Hamidreza; Mortazavi, Bohayra; Keshtkari, Leila; Zhuang, Xiaoying; Rabczuk, Timon Nanopore creation in MoS2 and graphene monolayers by nanoparticles impact: a reactive molecular dynamics study In this work, extensive reactive molecular dynamics simulations are conducted to analyze the nanopore creation by nano-particles impact over single-layer molybdenum disulfide (MoS2) with 1T and 2H phases. We also compare the results with graphene monolayer. In our simulations, nanosheets are exposed to a spherical rigid carbon projectile with high initial velocities ranging from 2 to 23 km/s. Results for three different structures are compared to examine the most critical factors in the perforation and resistance force during the impact. To analyze the perforation and impact resistance, kinetic energy and displacement time history of the projectile as well as perforation resistance force of the projectile are investigated. Interestingly, although the elasticity module and tensile strength of the graphene are by almost five times higher than those of MoS2, the results demonstrate that 1T and 2H-MoS2 phases are more resistive to the impact loading and perforation than graphene. For the MoS2nanosheets, we realize that the 2H phase is more resistant to impact loading than the 1T counterpart. Our reactive molecular dynamics results highlight that in addition to the strength and toughness, atomic structure is another crucial factor that can contribute substantially to impact resistance of 2D materials. The obtained results can be useful to guide the experimental setups for the nanopore creation in MoS2or other 2D lattices. Heidelberg Springer 13 Applied Physics A 2021 volume 127, article 541 1 13 urn:nbn:de:gbv:wim2-20210804-44756 10.1007/s00339-021-04693-5 Institut für Strukturmechanik (ISM) OPUS4-3296 Wissenschaftlicher Artikel Nguyen-Thanh, Nhon; Valizadeh, Navid; Nguyen, Manh Hung; Nguyen-Xuan, Hung; Zhuang, Xiaoying; Areias, Pedro; Zi, Goangseup; Bazilevs, Yuri; De Lorenzis, Laura; Rabczuk, Timon An extended isogeometric thin shell analysis based on Kirchhoff-Love theory An extended isogeometric thin shell analysis based on Kirchho_-Love theory 26 Computer Methods in Applied Mechanics and Engineering 265 291 Institut für Strukturmechanik (ISM) OPUS4-3337 Wissenschaftlicher Artikel Nguyen-Thanh, Nhon; Muthu, Jacob; Zhuang, Xiaoying; Rabczuk, Timon An adaptive three-dimensional RHT-splines formulation in linear elasto-statics and elasto-dynamics An adaptive three-dimensional RHT-splines formulation in linear elasto-statics and elasto-dynamics 16 Computational Mechanics 369 385 Institut für Strukturmechanik (ISM) OPUS4-3574 Wissenschaftlicher Artikel Nanthakumar, S.S.; Lahmer, Tom; Zhuang, Xiaoying; Zi, Goangseup; Rabczuk, Timon Detection of material interfaces using a regularized level set method in piezoelectric structures Detection of material interfaces using a regularized level set method in piezoelectric structures 23 Inverse Problems in Science and Engineering 153 176 Institut für Strukturmechanik (ISM) OPUS4-3277 Wissenschaftlicher Artikel Nanthakumar, S.S.; Lahmer, Tom; Zhuang, Xiaoying; Zi, Goangseup; Rabczuk, Timon Detection of material interfaces using a regularized level set method in piezoelectric structures Detection of material interfaces using a regularized level set method in piezoelectric structures Inverse Problems in Science and Engineering Institut für Strukturmechanik (ISM) OPUS4-3575 Wissenschaftlicher Artikel Nanthakumar, S.S.; Lahmer, Tom; Zhuang, Xiaoying; Park, Harold S.; Rabczuk, Timon Topology optimization of piezoelectric nanostructures Topology optimization of piezoelectric nanostructures 19 Journal of the Mechanics and Physics of Solids 316 335 Institut für Strukturmechanik (ISM) OPUS4-3141 Wissenschaftlicher Artikel Jiang, Jin-Wu; Zhuang, Xiaoying; Rabczuk, Timon Orientation dependent thermal conductance in single-layer MoS 2 We investigate the thermal conductivity in the armchair and zigzag MoS2 nanoribbons, by combining the non-equilibrium Green's function approach and the first-principles method. A strong orientation dependence is observed in the thermal conductivity. Particularly, the thermal conductivity for the armchair MoS2 nanoribbon is about 673.6 Wm−1 K−1 in the armchair nanoribbon, and 841.1 Wm−1 K−1 in the zigzag nanoribbon at room temperature. By calculating the Caroli transmission, we disclose the underlying mechanism for this strong orientation dependence to be the fewer phonon transport channels in the armchair MoS2 nanoribbon in the frequency range of [150, 200] cm−1. Through the scaling of the phonon dispersion, we further illustrate that the thermal conductivity calculated for the MoS2 nanoribbon is esentially in consistent with the superior thermal conductivity found for graphene. Scientific Reports urn:nbn:de:gbv:wim2-20170418-31417 10.1038/srep02209 Institut für Strukturmechanik (ISM) OPUS4-4676 Wissenschaftlicher Artikel Guo, Hongwei; Zhuang, Xiaoying; Chen, Pengwan; Alajlan, Naif; Rabczuk, Timon Analysis of three-dimensional potential problems in non-homogeneous media with physics-informed deep collocation method using material transfer learning and sensitivity analysis In this work, we present a deep collocation method (DCM) for three-dimensional potential problems in non-homogeneous media. This approach utilizes a physics-informed neural network with material transfer learning reducing the solution of the non-homogeneous partial differential equations to an optimization problem. We tested different configurations of the physics-informed neural network including smooth activation functions, sampling methods for collocation points generation and combined optimizers. A material transfer learning technique is utilized for non-homogeneous media with different material gradations and parameters, which enhance the generality and robustness of the proposed method. In order to identify the most influential parameters of the network configuration, we carried out a global sensitivity analysis. Finally, we provide a convergence proof of our DCM. The approach is validated through several benchmark problems, also testing different material variations. 22 Engineering with Computers 2022 1 22 urn:nbn:de:gbv:wim2-20220811-46764 10.1007/s00366-022-01633-6 Institut für Strukturmechanik (ISM) OPUS4-6366 Wissenschaftlicher Artikel Guo, Hongwei; Alajlan, Naif; Zhuang, Xiaoying; Rabczuk, Timon Physics-informed deep learning for three-dimensional transient heat transfer analysis of functionally graded materials We present a physics-informed deep learning model for the transient heat transfer analysis of three-dimensional functionally graded materials (FGMs) employing a Runge-Kutta discrete time scheme. Firstly, the governing equation, associated boundary conditions and the initial condition for transient heat transfer analysis of FGMs with exponential material variations are presented. Then, the deep collocation method with the Runge-Kutta integration scheme for transient analysis is introduced. The prior physics that helps to generalize the physics-informed deep learning model is introduced by constraining the temperature variable with discrete time schemes and initial/boundary conditions. Further the fitted activation functions suitable for dynamic analysis are presented. Finally, we validate our approach through several numerical examples on FGMs with irregular shapes and a variety of boundary conditions. From numerical experiments, the predicted results with PIDL demonstrate well agreement with analytical solutions and other numerical methods in predicting of both temperature and flux distributions and can be adaptive to transient analysis of FGMs with different shapes, which can be the promising surrogate model in transient dynamic analysis. Berlin Springer 12 Computational Mechanics 2023 1 12 urn:nbn:de:gbv:wim2-20230517-63666 10.1007/s00466-023-02287-x Professur Modellierung und Simulation - Mechanik OPUS4-3341 Wissenschaftlicher Artikel Ghasemi, Hamid; Rafiee, Roham; Zhuang, Xiaoying; Muthu, Jacob; Rabczuk, Timon Uncertainties propagation in metamodel-based probabilistic optimization of CNT/polymer composite structure using stochastic multi-scale modeling Uncertainties propagation in metamodel-based probabilistic optimization of CNT/polymer composite structure using stochastic multi-scale modeling 10 Computational Materials Science 295 305 Institut für Strukturmechanik (ISM) OPUS4-3283 Wissenschaftlicher Artikel Ghasemi, Hamid; Brighenti, Roberto; Zhuang, Xiaoying; Muthu, Jacob; Rabczuk, Timon Optimum fiber content and distribution in fiber-reinforced solids using a reliability and NURBS based sequential optimization approach Optimum _ber content and distribution in _ber-reinforced solids using a reliability and NURBS based sequential optimization approach 13 Structural and Multidisciplinary Optimization 99 112 Institut für Strukturmechanik (ISM) OPUS4-3340 Wissenschaftlicher Artikel Ghasemi, Hamid; Brighenti, Roberto; Zhuang, Xiaoying; Muthu, Jacob; Rabczuk, Timon Optimization of fiber distribution in fiber reinforced composite by using NURBS functions Optimization of fiber distribution in fiber reinforced composite by using NURBS functions 10 Computational Materials Science 463 473 Institut für Strukturmechanik (ISM) OPUS4-3304 Wissenschaftlicher Artikel Ghasemi, Hamid; Brighenti, Roberto; Zhuang, Xiaoying; Muthu, Jacob; Rabczuk, Timon Sequential reliability based optimization of fiber content and dispersion in fiber reinforced composite by using NURBS finite elements Sequential reliability based optimization of fiber content and dispersion in fiber reinforced composite by using NURBS finite elements Structural and Multidisciplinary Optimization Institut für Strukturmechanik (ISM) OPUS4-4677 Wissenschaftlicher Artikel Chakraborty, Ayan; Anitescu, Cosmin; Zhuang, Xiaoying; Rabczuk, Timon Domain adaptation based transfer learning approach for solving PDEs on complex geometries In machine learning, if the training data is independently and identically distributed as the test data then a trained model can make an accurate predictions for new samples of data. Conventional machine learning has a strong dependence on massive amounts of training data which are domain specific to understand their latent patterns. In contrast, Domain adaptation and Transfer learning methods are sub-fields within machine learning that are concerned with solving the inescapable problem of insufficient training data by relaxing the domain dependence hypothesis. In this contribution, this issue has been addressed and by making a novel combination of both the methods we develop a computationally efficient and practical algorithm to solve boundary value problems based on nonlinear partial differential equations. We adopt a meshfree analysis framework to integrate the prevailing geometric modelling techniques based on NURBS and present an enhanced deep collocation approach that also plays an important role in the accuracy of solutions. We start with a brief introduction on how these methods expand upon this framework. We observe an excellent agreement between these methods and have shown that how fine-tuning a pre-trained network to a specialized domain may lead to an outstanding performance compare to the existing ones. As proof of concept, we illustrate the performance of our proposed model on several benchmark problems. 20 Engineering with Computers 2022 1 20 urn:nbn:de:gbv:wim2-20220811-46776 10.1007/s00366-022-01661-2 Institut für Strukturmechanik (ISM) OPUS4-3335 Wissenschaftlicher Artikel Budarapu, Pattabhi Ramaiah; Gracie, Robert; Yang, Shih-Wei; Zhuang, Xiaoying; Rabczuk, Timon Efficient Coarse Graining in Multiscale Modeling of Fracture Efficient Coarse Graining in Multiscale Modeling of Fracture 17 Theoretical and Applied Fracture Mechanics 126 143 Institut für Strukturmechanik (ISM)