TY - THES A1 - Ahmad, Sofyan T1 - Reference Surface-Based System Identification N2 - Environmental and operational variables and their impact on structural responses have been acknowledged as one of the most important challenges for the application of the ambient vibration-based damage identification in structures. The damage detection procedures may yield poor results, if the impacts of loading and environmental conditions of the structures are not considered. The reference-surface-based method, which is proposed in this thesis, is addressed to overcome this problem. In the proposed method, meta-models are used to take into account significant effects of the environmental and operational variables. The usage of the approximation models, allows the proposed method to simply handle multiple non-damaged variable effects simultaneously, which for other methods seems to be very complex. The input of the meta-model are the multiple non-damaged variables while the output is a damage indicator. The reference-surface-based method diminishes the effect of the non-damaged variables to the vibration based damage detection results. Hence, the structure condition that is assessed by using ambient vibration data at any time would be more reliable. Immediate reliable information regarding the structure condition is required to quickly respond to the event, by means to take necessary actions concerning the future use or further investigation of the structures, for instance shortly after extreme events such as earthquakes. The critical part of the proposed damage detection method is the learning phase, where the meta-models are trained by using input-output relation of observation data. Significant problems that may encounter during the learning phase are outlined and some remedies to overcome the problems are suggested. The proposed damage identification method is applied to numerical and experimental models. In addition to the natural frequencies, wavelet energy and stochastic subspace damage indicators are used. T3 - ISM-Bericht // Institut für Strukturmechanik, Bauhaus-Universität Weimar - 2013,3 KW - System Identification KW - Schadensdetektionsverfahren KW - Referenzfläche Y1 - 2013 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:gbv:wim2-20140205-21132 ER - TY - JOUR A1 - Areias, Pedro A1 - Rabczuk, Timon T1 - Finite strain fracture of plates and shells with configurational forces and edge rotation JF - International Journal for Numerical Methods in Engineering N2 - Finite strain fracture of plates and shells with configurational forces and edge rotation KW - Angewandte Mathematik KW - Strukturmechanik Y1 - 2013 ER - TY - JOUR A1 - Areias, Pedro A1 - Rabczuk, Timon A1 - Dias-da-Costa, D. T1 - Assumed-metric spherically-interpolated quadrilateral shell element JF - Finite Elements in Analysis and Design N2 - Assumed-metric spherically-interpolated quadrilateral shell element KW - Angewandte Mathematik KW - Strukturmechanik Y1 - 2013 SP - 53 EP - 67 ER - TY - JOUR A1 - Areias, Pedro A1 - Rabczuk, Timon A1 - Dias-da-Costa, D. T1 - Asymmetric Shell Elements Based on a Corrected Updated-Lagrangian Approach JF - CMES: Computer Modeling in Engineering and Sciences N2 - Asymmetric Shell Elements Based on a Corrected Updated-Lagrangian Approach KW - Angewandte Mathematik KW - Strukturmechanik Y1 - 2013 ER - TY - JOUR A1 - Bakar, I. A1 - Kramer, O. A1 - Bordas, Stéphane Pierre Alain A1 - Rabczuk, Timon T1 - Optimization of Elastic Properties and Weaving Patterns of Woven Composites JF - Composite Structures N2 - Optimization of Elastic Properties and Weaving Patterns of Woven Composites KW - Angewandte Mathematik KW - Strukturmechanik Y1 - 2013 SP - 575 EP - 591 ER - TY - JOUR A1 - Banihani, Suleiman A1 - Rabczuk, Timon A1 - Almomani, Thakir T1 - POD for real-time simulation of hyperelastic soft biological tissue using the point collocation method of finite spheres JF - Mathematical Problems in Engineering N2 - The point collocation method of finite spheres (PCMFS) is used to model the hyperelastic response of soft biological tissue in real time within the framework of virtual surgery simulation. The proper orthogonal decomposition (POD) model order reduction (MOR) technique was used to achieve reduced-order model of the problem, minimizing computational cost. The PCMFS is a physics-based meshfree numerical technique for real-time simulation of surgical procedures where the approximation functions are applied directly on the strong form of the boundary value problem without the need for integration, increasing computational efficiency. Since computational speed has a significant role in simulation of surgical procedures, the proposed technique was able to model realistic nonlinear behavior of organs in real time. Numerical results are shown to demonstrate the effectiveness of the new methodology through a comparison between full and reduced analyses for several nonlinear problems. It is shown that the proposed technique was able to achieve good agreement with the full model; moreover, the computational and data storage costs were significantly reduced. KW - Chirurgie KW - Finite-Elemente-Methode Y1 - 2013 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:gbv:wim2-20170413-31203 ER - TY - JOUR A1 - Jiang, Jin-Wu A1 - Park, Harold S. A1 - Gall, K. A1 - Leach, A. A1 - Rabczuk, Timon T1 - A Surface Stacking Fault Energy Approach to Predicting Defect Nucleation in Surface-Dominated Nanostructures JF - Journal of the Mechanics and Physics of Solids N2 - A Surface Stacking Fault Energy Approach to Predicting Defect Nucleation in Surface-Dominated Nanostructures KW - Angewandte Mathematik KW - Strukturmechanik Y1 - 2013 ER - TY - JOUR A1 - Jiang, Jin-Wu A1 - Rabczuk, Timon T1 - Mechanical Oscillation of Kinked Silicon Nanowires: a Natural Nanoscale Spring JF - Applied Physics Letters N2 - Mechanical Oscillation of Kinked Silicon Nanowires: a Natural Nanoscale Spring KW - Angewandte Mathematik KW - Strukturmechanik Y1 - 2013 ER - TY - JOUR A1 - Jiang, Jin-Wu A1 - Rabczuk, Timon T1 - Modulation of Thermal Conductivity in kinked Silicon Nanowires: Phonon interchanging and pinching effects or Reduction of thermal conductivity in kinked silicon nanowire superlattices JF - Nano Letters N2 - Modulation of Thermal Conductivity in kinked Silicon Nanowires: Phonon interchanging and pinching effects or Reduction of thermal conductivity in kinked silicon nanowire superlattices KW - Angewandte Mathematik KW - Strukturmechanik Y1 - 2013 ER - TY - JOUR A1 - Jiang, Jin-Wu A1 - Wang, Bing-Shen A1 - Rabczuk, Timon T1 - Why twisting angles are diverse in graphene Moir’e patterns? JF - Journal of Applied Physics N2 - Why twisting angles are diverse in graphene Moir’e patterns? KW - Angewandte Mathematik KW - Strukturmechanik Y1 - 2013 ER -