TY - JOUR A1 - Ansari, Meisam A1 - Zacharias, Christin A1 - Könke, Carsten T1 - Metaconcrete: An Experimental Study on the Impact of the Core-Coating Inclusions on Mechanical Vibration JF - materials N2 - Resonance vibration of structures is an unpleasant incident that can be conventionally avoided by using a Tuned Mass Damper (TMD). The scope of this paper contains the utilization of engineered inclusions in concrete as damping aggregates to suppress resonance vibration similar to a TMD. The inclusions are composed of a stainless-steel core with a spherical shape coated with silicone. This configuration has been the subject of several studies and it is best known as Metaconcrete. This paper presents the procedure of a free vibration test conducted with two small-scaled concrete beams. The beams exhibited a higher damping ratio after the core-coating element was secured to them. Subsequently, two meso-models of small-scaled beams were created: one representing conventional concrete and the other representing concrete with the core-coating inclusions. The frequency response curves of the models were obtained. The change in the response peak verified the ability of the inclusions to suppress the resonance vibration. This study concludes that the core-coating inclusions can be utilized in concrete as damping aggregates. KW - Beton KW - Schwingungsdämpfung KW - metaconcrete KW - damping aggregate KW - vibration absorber Y1 - 2023 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:gbv:wim2-20230315-49370 UR - https://www.mdpi.com/1996-1944/16/5/1836 VL - 2023 IS - Volume 16, Issue 5, article 1836 SP - 1 EP - 18 PB - MDPI CY - Basel ER - TY - JOUR A1 - Ansari, Meisam A1 - Tartaglione, Fabiola A1 - Könke, Carsten T1 - Experimental Validation of Dynamic Response of Small-Scale Metaconcrete Beams at Resonance Vibration JF - materials N2 - Structures and their components experience substantially large vibration amplitudes at resonance, which can cause their failure. The scope of this study is the utilization of silicone-coated steel balls in concrete as damping aggregates to suppress the resonance vibration. The heavy steel cores oscillate with a frequency close to the resonance frequency of the structure. Due to the phase difference between the vibrations of the cores and the structure, the cores counteract the vibration of the structure. The core-coating inclusions are randomly distributed in concrete similar to standard aggregates. This mixture is referred to as metaconcrete. The main goal of this work is to validate the ability of the inclusions to suppress mechanical vibration through laboratory experiments. For this purpose, two small-scale metaconcrete beams were cast and tested. In a free vibration test, the metaconcrete beams exhibited a larger damping ratio compared to a similar beam cast from conventional concrete. The vibration amplitudes of the metaconcrete beams at resonance were measured with a frequency sweep test. In comparison with the conventional concrete beam, both metaconcrete beams demonstrated smaller vibration amplitudes. Both experiments verified an improvement in the dynamic response of the metaconcrete beams at resonance vibration. KW - Beton KW - metaconcrete KW - Schwingungsdämpfung KW - damping aggregate KW - vibration absorber KW - free vibration test KW - frequency sweep test Y1 - 2023 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:gbv:wim2-20230818-64154 UR - https://www.mdpi.com/1996-1944/16/14/5029 VL - 2023 IS - volume 16, issue 14, article 5029 SP - 1 EP - 17 PB - MDPI CY - Basel ER - TY - INPR A1 - Radmard Rahmani, Hamid A1 - Könke, Carsten T1 - Passive Control of Tall Buildings Using Distributed Multiple Tuned Mass Dampers N2 - The vibration control of the tall building during earthquake excitations is a challenging task due to their complex seismic behavior. This paper investigates the optimum placement and properties of the Tuned Mass Dampers (TMDs) in tall buildings, which are employed to control the vibrations during earthquakes. An algorithm was developed to spend a limited mass either in a single TMD or in multiple TMDs and distribute them optimally over the height of the building. The Non-dominated Sorting Genetic Algorithm (NSGA – II) method was improved by adding multi-variant genetic operators and utilized to simultaneously study the optimum design parameters of the TMDs and the optimum placement. The results showed that under earthquake excitations with noticeable amplitude in higher modes, distributing TMDs over the height of the building is more effective in mitigating the vibrations compared to the use of a single TMD system. From the optimization, it was observed that the locations of the TMDs were related to the stories corresponding to the maximum modal displacements in the lower modes and the stories corresponding to the maximum modal displacements in the modes which were highly activated by the earthquake excitations. It was also noted that the frequency content of the earthquake has significant influence on the optimum location of the TMDs. KW - Schwingungsdämpfer KW - Hochbau KW - tall buildings KW - passive control KW - genetic algorithm KW - tuned mass dampers Y1 - 2019 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:gbv:wim2-20190311-38597 UR - https://www.researchgate.net/publication/330508976_Seismic_Control_of_Tall_Buildings_Using_Distributed_Multiple_Tuned_Mass_Dampers ER - TY - JOUR A1 - Nguyen-Tuan, Long A1 - Könke, Carsten A1 - Bettzieche, Volker A1 - Lahmer, Tom T1 - Numerical modeling and validation for 3D coupled-nonlinear thermo-hydro-mechanical problems in masonry dams JF - Computers & Structures N2 - Numerical modeling and validation for 3D coupled-nonlinear thermo-hydro-mechanical problems in masonry dams KW - Angewandte Mathematik KW - Stochastik KW - Strukturmechanik Y1 - 2017 SP - 143 EP - 154 ER - TY - JOUR A1 - Lahmer, Tom A1 - Nguyen-Tuan, Long A1 - Könke, Carsten A1 - Bettzieche, Volker T1 - Thermo-hydro-mechanische 3-D-Simulation von Staumauern‐Modellierung und Validierung JF - WASSERWIRTSCHAFT N2 - Thermo-hydro-mechanische 3-D-Simulation von Staumauern‐Modellierung und Validierung KW - Angewandte Mathematik KW - Stochastik KW - Strukturmechanik Y1 - 2016 SP - 27 EP - 30 ER - TY - JOUR A1 - Luu, M. A1 - Martinez-Rodrigo, M.D. A1 - Zabel, Volkmar A1 - Könke, Carsten T1 - H∞ optimization of fluid viscous dampers for reducing vibrations of high-speed railway bridges JF - Journal of Sound and Vibration N2 - H∞ optimization of fluid viscous dampers for reducing vibrations of high-speed railway bridges KW - Angewandte Mathematik KW - Strukturmechanik Y1 - 2014 SP - 2421 EP - 2442 ER - TY - JOUR A1 - Schrader, Kai A1 - Könke, Carsten T1 - Distributed computing for the nonlinear analysis of multiphase composites JF - Advances in Engineering Software N2 - Distributed computing for the nonlinear analysis of multiphase composites KW - Angewandte Mathematik KW - Strukturmechanik Y1 - 2013 SP - 20 EP - 32 ER - TY - CHAP A1 - Theiler, Michael A1 - Könke, Carsten ED - Maia, Nuno T1 - Damping in Bolted Joints T2 - Proceedings of International Conference on Structural Engineering Dynamics (ICEDyn) 2013 N2 - With the help of modern CAE-based simulation processes, it is possible to predict the dynamic behavior of fatigue strength problems in order to improve products of many industries, e.g. the building, the machine construction or the automotive industry. Amongst others, it can be used to improve the acoustic design of automobiles in an early development stage. Nowadays, the acoustics of automobiles plays a crucial role in the process of vehicle development. Because of the advanced demand of comfort and due to statutory rules the manufacturers are faced with the challenge of optimizing their car’s sound emissions. The optimization includes not only the reduction of noises. Lately with the trend to hybrid and electric cars, it has been shown that vehicles can become too quiet. Thus, the prediction of structural and acoustic properties based on FE-simulations is becoming increasingly important before any experimental prototype is examined. With the state of the art, qualitative comparisons between different implementations are possible. However, an accurate and reliable quantitative prediction is still a challenge. One aspect in the context of increasing the prediction quality of acoustic (or general oscillating) problems - especially in power-trains of automobiles - is the more accurate implementation of damping in joint structures. While material damping occurs globally and homogenous in a structural system, the damping due to joints is a very local problem, since energy is especially dissipated in the vicinity of joints. This paper focusses on experimental and numerical studies performed on a single (extracted) screw connection. Starting with experimental studies that are used to identify the underlying physical model of the energy loss, the locally influencing parameters (e.g. the damping factor) should be identified. In contrast to similar research projects, the approach tends to a more local consideration within the joint interface. Tangential stiffness and energy loss within the interface are spatially distributed and interactions between the influencing parameters are regarded. As a result, the damping matrix is no longer proportional to mass or stiffness matrix, since it is composed of the global material damping and the local joint damping. With this new approach, the prediction quality can be increased, since the local distribution of the physical parameters within the joint interface corresponds much closer to the reality. KW - Damping Y1 - 2013 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:gbv:wim2-20130701-19709 SN - 978-989-96276-4-2 ER - TY - CHAP A1 - Ahmad, Sofyan A1 - Zabel, Volkmar A1 - Könke, Carsten T1 - WAVELET-BASED INDICATORS FOR RESPONSE SURFACE MODELS IN DAMAGE IDENTIFICATION OF STRUCTURES T2 - Digital Proceedings, International Conference on the Applications of Computer Science and Mathematics in Architecture and Civil Engineering : July 04 - 06 2012, Bauhaus-University Weimar N2 - In this paper, wavelet energy damage indicator is used in response surface methodology to identify the damage in simulated filler beam railway bridge. The approximate model is addressed to include the operational and surrounding condition in the assessment. The procedure is split into two stages, the training and detecting phase. During training phase, a so-called response surface is built from training data using polynomial regression and radial basis function approximation approaches. The response surface is used to detect the damage in structure during detection phase. The results show that the response surface model is able to detect moderate damage in one of bridge supports while the temperatures and train velocities are varied. KW - Angewandte Mathematik KW - Computerunterstütztes Verfahren KW - Angewandte Informatik Y1 - 2012 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:gbv:wim2-20170306-27588 SN - 1611-4086 ER - TY - JOUR A1 - Schrader, Kai A1 - Könke, Carsten T1 - Hybrid computing models for large-scale heterogeneous 3d microstructures JF - International Journal for Multiscale Computational Engineering N2 - Hybrid computing models for large-scale heterogeneous 3d microstructures KW - Angewandte Mathematik KW - Strukturmechanik Y1 - 2011 SP - 365 EP - 377 ER -