Nonlinear velocity dampers (NVDs) embedded in coupling beams may enhance the seismic performance of frame–core tube structures by dissipating energy and limiting structural damage. This study evaluates the seismic performance of a 20-story reinforced concrete (RC) frame–core tube building incorporating NVD-equipped coupling beams. Parametric studies are conducted at the frequent earthquake (FE) level, and nonlinear time-history analyses are performed at the design-basis earthquake (DBE) and rare earthquake (RE) levels. The results show that wall-pier flexure is the primary contributor to damper deformation, and mid-span placement is found to be relatively favorable. The optimal damping coefficient varies with the engineering demand parameters, whether base shear, drift, or additional damping, indicating that damping coefficient should be chosen based on a balanced consideration. For the N. Palm Springs ground-motion record considered in the damage assessment, the NVD-equipped models exhibit less flexural damage than the reference model for varying damping coefficients at both DBE and RE levels. These findings provide case-specific design guidance for applying NVD-equipped coupling beams in comparable RC frame–core tube buildings.
Earthquakes produce significant lateral forces on structures, which may lead to excessive displacement, structural
instability, and collapse if proper seismic resistant measures are not adopted. The present study focuses on the comparative
seismic performance evaluation of a G+11 reinforced cement concrete (RCC) building incorporated with different vibration
control system using ETABS 20. The building was analyzed for Seismic Zone V using the Response Spectrum Analysis (RSA)
method in accordance with the provisions of IS 1893 (Part 1): 2016. Six structural models were considered in the study, namely
bare frame structure, fluid viscous damper model, friction damper model, X-bracing model, shear wall model, and lead rubber
bearing (LRB) base isolated model. The seismic performance of each model was evaluated based on parameters such as
maximum storey displacement, storey drift and storey shear. The results obtained from the analysis indicate that the Shear Wall
model provides the most effective reduction in displacement and drift due to its Enhanced stiffness, although the shear wall and
bracing systems significantly improve structural stiffness but attract higher seismic forces hence greater base shear than bare
frame model. The fluid viscous damper and friction damper showed overall good seismic performance by reducing the overall
displacement, drift and storey shear without attracting higher seismic forces. The base isolated model increases the displacement
due to increased flexibility in the structure but reduces drift and force transmission into the structure. The study concludes that
vibration control systems considerably enhance the seismic performance of RCC structures and assist in improving structural
safety in earthquake-prone regions.
Utkarsh Mishra, Rakesh Grover· International Journal for Re...· 0 citations
To improve the seismic performance and post-earthquake recoverability of low- and mid-rise steel frames, this study investigates the seismic performance and layout strategy of a self-centering friction damper (SCFD) through experimental and numerical studies. The SCFD combines the superelastic restoring capability of shape memory alloy (SMA) bars with the energy dissipation provided by non-asbestos organic (NAO) friction materials. Monotonic and cyclic tests were conducted to characterize the mechanical behavior of Ni–50.8 at. % Ti SMA bars and the hysteretic performance of the SCFD, based on which a numerical model of the damper was established and validated. An uncontrolled frame and four controlled frames employing diagonal, chevron, improved lower toggle-brace, and improved upper toggle-brace layouts were comparatively investigated to evaluate the effects of brace configuration, installation position, and damper quantity on seismic performance. The proposed damper exhibited an equivalent damping ratio ranging from 24% to 32%. When the SMA strain exceeded 6%, the residual deformation of the damper increased significantly, indicating that excessive SMA deformation should be avoided in practical design. Among the investigated configurations, the improved upper toggle-brace layout, combined with additional dampers installed at the first story, showed the best overall performance. Compared with the uncontrolled multi-story structure, the residual inter-story drift ratio was reduced by 76.7–93.5%, while the maximum acceleration reduction reached 28.9%. However, local acceleration amplification was observed in some cases because of the increased structural stiffness. These findings provide practical guidance for the layout design and engineering application of self-centering friction dampers in low- and mid-rise steel frames.
Lu Wang, Zhaoqun Chang, Yahui Zhang et al.· Buildings· 0 citations
Steel moment-resisting frames are widely used in seismic regions, but conventional beam–column connections often suffer from concentrated damage and difficult post-earthquake repair. To address these issues, this study proposes a novel replaceable energy-dissipating slit beam–column joint for steel frames. To enhance structural energy dissipation efficiency, mitigate seismic damage, and enable rapid post-earthquake repair, the joint utilizes connectors as energy-dissipating elements such that plastic deformation is confined to these connectors while main beams and columns remain elastic throughout the loading history. A quasi-static test was conducted on the proposed joint. The test results indicate that the hysteresis loops are full and fusiform, demonstrating excellent energy dissipation capacity. The joint exhibits ductility coefficients of 6.30 and 5.27 under positive and negative loading, respectively, and the equivalent viscous damping coefficient remains above 0.30 after a rotation of 0.025 rad. Furthermore, plastic damage is primarily sustained by the connectors, with no evident yielding observed in other structural members. To further investigate the joint, it was applied to a three-story, four-bay, three-span steel frame for finite element analyses. Compared with a conventional rigid joint frame, the proposed joint frame under rare earthquakes reduces roof displacements by 20.97% (with the X-direction as the primary direction) and 16.23% (with the Y-direction as the primary direction), and maximum interstory drift ratios by 18.06% (with the X-direction as the primary direction) and 15.55% (with the Y-direction as the primary direction), while satisfying the code-specified limits of 1/250 for elastic and 1/50 for elastoplastic interstory drift ratios, thereby indicating its superior seismic performance.
This study investigates the seismic behaviour of a 10-storey shear-type building subjected to eleven near-field earthquake records while explicitly accounting for nonlinear soil-structure interaction (SSI). To improve seismic performance, a novel multiple active friction-tuned mass damper (MAFTMD) framework is proposed by integrating multiple friction-tuned mass dampers (MFTMDs) with an enhanced integral-derivative tilted (I-DT) control strategy. The nonlinear behaviour of the supporting soil is represented using the Hardin-Drnevich model, enabling strain-dependent stiffness degradation and damping effects to be captured under stiff, soft, and very soft soil conditions. The parameters of the MTMD and MFTMD configurations, along with the gains of the enhanced I-DT controller implemented in the MAFTMD system, are optimized using a multi-objective thermal exchange optimization (MOTEO) algorithm. The optimization simultaneously minimizes peak storey displacement and acceleration while satisfying inter-storey drift ratio constraints. The results demonstrate that incorporating friction mechanisms significantly enhances energy dissipation and structural response mitigation as compared to conventional MTMD systems. Furthermore, the proposed MAFTMD framework provides the most stable and effective overall performance under varying near-field earthquake characteristics and nonlinear soil conditions. The study also shows that nonlinear SSI strongly affects the performance and optimization of structural control systems. Overall, the proposed framework combines friction-based damping, active control, and nonlinear soil modelling to improve the seismic performance of mid-rise buildings under near-field earthquakes.
Morteza Akbari, M. Seifi, T. Falborski et al.· Archives of Civil and Mechan...· 0 citations
Control systems such as base isolators and dampers are widely used to reduce the seismic energy input to structures. Among passive control devices, Tuned Liquid Dampers (TLDs) mitigate structural vibrations through sloshing of the contained liquid, which generates counteracting inertial forces without requiring external power. The effectiveness of TLD systems strongly depends on the selected mass ratio. This study evaluates the influence of TLD mass ratio on the seismic performance of a 10-story reinforced concrete frame building, with particular emphasis on plastic deformation demands and seismic-induced residual displacements. TLDs with different mass ratios are considered to assess their impact on interstory drift, column plastic rotations, and post-earthquake residual response. The results indicate that while increasing the mass ratio may lead to higher plastic deformation demands in certain cases, it consistently reduces residual displacements. Among the investigated configurations, a 5% mass ratio provides the most balanced performance, achieving significant reductions in residual displacement without substantial amplification of deformation demands. These findings highlight the importance of carefully tuning TLD mass ratio to achieve improved post-earthquake functionality while avoiding adverse increases in structural demand.
Birkan Dağ, Muzaffer Börekçi, M. Gençoğlu· Dicle Üniversitesi Mühendisl...· 0 citations
Designing high-rise reinforced concrete (RC) structures with adequate lateral stability is essential, especially in areas prone to earthquakes and strong winds. A G+9 RC framed structure was examined in this research with and without shear walls, utilizing STAAD as a tool for comparison.The PRO CONNECT Version. Model A is a standard reinforced concrete momentresisting frame, while Model B is an improved version of Model A with three shear wall components positioned in the middle to increase lateral stiffness. For Seismic Zone II circumstances, both models were tested under dead load, live load, wind load, and seismic load according to IS 1893 (Part 1):2016. Displacements at nodes, forms deflected, stress distribution on plates, and bending moment behavior of frame elements were used to assess the structural reaction. Through altering the distribution of seismic and wind forces and minimizing horizontal displacements, the comparison study demonstrated that the addition of shear walls substantially increased the building's lateral stiffness. When compared to the bare frame model, the shear wall system lowered the bending moments in the columns by absorbing most of the lateral load. A lack of change in the gravity load response, including vertical displacement and slab stress behavior, suggests that shear walls mainly affected lateral performance and had no negative effect on gravity load behavior. The research shows that medium-rise RC structures with shear walls have better drift control, lower member demands, and better structural performance overall, and that they resist lateral loads efficiently. Buildings vulnerable to seismic and wind forces should use wall-frame dual systems, according to the results.
A UMA DEVI, Dr. B. SHARATH CHANDRA· International Journal of AI...· 0 citations
We use cookies to run the site and, with your consent, for analytics and to show ads.
See our Cookie Policy.
