Muhammed Zain Kangda

Bio: Muhammed Zain Kangda is an academic researcher from Visvesvaraya National Institute of Technology. The author has contributed to research in topics: Structural engineering & Engineering. The author has an hindex of 3, co-authored 7 publications receiving 25 citations. Previous affiliations of Muhammed Zain Kangda include Massachusetts Institute of Technology.

The Effect of LRB Parameters on Structural Responses for Blast and Seismic Loads

Abstract: In the present paper, passive control technique such as base isolation system is studied under earthquake ground motions and underground blast-induced vibrations. The performance of the lead rubber bearing (LRB), idealized as Bouc–Wen model in mitigating the structural responses of a five-storey building model, is investigated. The earthquake ground motions are selected from ground motion database available on the portal COSMOS Virtual Data Centre, whereas the underground blast is modeled as an exponential decaying function as prescribed by Carvalho and Battista (Proc Inst Civ Eng Struct Build 156(3):243–253, 2003). The aim of the study is to analyze the effect of isolation parameters such as damping ratio, yield strength, post-yield stiffness ratio and yield displacement on the structural responses of the base-isolated building. Newmark’s step-by-step integration method is adopted to evaluate the structural responses of the building. It is observed that the LRB is very effective in reducing the structural accelerations and storey drifts induced in the building due to ground-induced vibration. The comparison of results show that high value of yield strength harvests low bearing displacement and low percentage reduction in the top floor absolute acceleration. In addition, the study also evaluates the energy dissipated by the isolated structure. The energy dissipated by the base-isolated (LRB) building subjected to blast-induced vibrations, show that an optimum value of yield strength is found to be in the range of 10–20% of the total weight of the structure.

Positive-Phase Blast Effects on Base-Isolated Structures

Abstract: The last few decades have shown a dramatic increase in the number of man-made disaster activities resulting in extensive life loss and structural failures. The explosive devices used in these heinous acts result in blast wave loading. Therefore, the present structural engineers require comprehensive expertise to analyze and design blast-resistant structures. The present study aims to develop blast load time history based on the previous research works and demonstrates the effectiveness of base isolation technique such as lead rubber bearings in mitigating the structural responses under the effect of blast loading. Two base-isolated building models systems are analyzed to examine the role of structural control strategies subjected to blast loading. Various isolation parameters are also incorporated in the present investigation in improving the structural performance subjected to this extreme dynamic loading. The study concludes that base isolation is an efficient technique in reducing structural output parameters such as peak storey displacement, storey drift and root mean square absolute acceleration values due to post-blast effects. Energy-based equations are also examined in the study to evaluate the hysteretic energy dissipated by the system subjected to blast loading.

Performance Evaluation of Moment-Resisting Steel Frame Buildings Under Seismic and Blast-Induced Vibrations

Abstract: The paper is an attempt to evaluate the efficiency of passive control techniques such as base isolation system (e.g. Lead/Rubber Bearing) and fluid viscous dampers subjected to earthquake ground motions and underground blast-induced vibrations. Two moment-resisting steel frame buildings are analyzed to evaluate the structural responses under dynamic excitations. The effect of vertical irregularity on the performance of passive control techniques in mitigating the responses of the building is also studied. Non-linear dynamic analysis has been conducted on regular and irregular steel structures. The study investigates the effect of isolation period on the structural responses. The isolators are designed based on the design procedures developed by various researchers. The technical specifications of fluid viscous dampers have been selected from M/s Taylor Devices, USA. The structural responses and energy dissipated by these control techniques is evaluated and a comparative study is also carried out amongst control techniques under blast and seismic excitations. Both the selected passive control techniques have proved to be very effective in reducing the structural responses and forces induced in the building owing to ground-induced vibration.

Response control of adjacent structures subjected to blast-induced vibrations

Abstract: The response reduction efficiency of passive control viscous dampers installed between adjacent structures subjected to blast-induced vibrations was investigated. The blast-induced vibrations studi...

Performance of Linear and Nonlinear damper connected buildings under blast and seismic excitations

Abstract: During an earthquake, adjacent buildings with insufficient separations often collide into each imposing unexpected impact loading on buildings causing severe damage and even collapse of many buildings In the present study, the passive control of closely spaced fixed base structures is investigated under the effects of earthquakes and blast-induced vibrations The study analyzes two closely spaced dynamically dissimilar fixed base buildings connected using linear and nonlinear fluid viscous dampers when subjected to blast and seismic excitations A parametric study on the damping coefficient of fluid dampers is conducted to obtain an optimum damping coefficient for linear and nonlinear fluid viscous dampers The present study investigates the comparative performance behavior of the linear and nonlinear dampers in response reduction of adjacent buildings under blast and earthquake motions The placement of dampers in the response mitigation due to the selected excitations is also reviewed Results exhibit the efficiency of viscous dampers in reducing the structural responses of flexible buildings It is also concluded that the placement of dampers at the top floor alone yields significant reduction in the structural responses when compared with the placement of dampers at all floors

Applications of Nonlinearity in Passive Vibration Control: A Review

Abstract: Vibration present on various levels in many engineering fields and hence vibration mitigation has become a subject of intense study. The nonlinear vibration isolation devices are effective for broad frequency bandwidth and can provide better vibration isolation than linear devices. The need for nonlinearity in stiffness and damping characteristics has motivated researchers to apply the nonlinearity found in mechanisms or materials in the passive vibration control devices. This review discusses the applications of nonlinearity in the passive vibration control devices to provide an understanding of how the nonlinearity is applied and useful in the implemented system. Further, applications for nonlinearity can also be extended in the energy harvesting devices, Nonlinear energy sink, metamaterials for the purpose of vibration isolation and energy harvesting. The need for nonlinearity also encouraged research work through inspiration from the nature called bio-inspired devices. The bio-inspired devices mimic the nonlinearity of the biological system to suppress the vibrations. The nonlinear passive isolation is effective for wide frequency bandwidth than the linear isolation system. Further, the nonlinear systems also reduce transmissibility much efficiently than the linear system. The nonlinear energy harvesting system shows a great scope to harvest energy from wide ranges of excitations. The bio-inspired devices also are proven to be effective in vibration isolation. Additionally the design of the metamaterial with nonlinearity in the microstructure, proves to be promising in the vibration suppression applications. Based on the review, the nonlinearity introduced into the systems has greater benefits than the linear systems.

Flexural behavior of reinforced concrete beams using waste marble powder towards application of sustainable concrete

Abstract: The performance of waste marble powder as a partial replacement for cement is examined with the aim to achieve more sustainable concrete. Pursuant to this goal, a total of 15 specimens were manufactured and then tested to examine the bending behavior. The effects of longitudinal reinforcement ratio and waste marble powder ratio were selected as variables. The experimental results showed that different proportions of tension reinforcement and waste marble powder had different crack and bending impacts on reinforced concrete beams. As the waste marble powder amount in the concrete mixture is increased from 0% to 40%, it was detected that the crack type changes from a shear crack from to a flexural crack as the amount of waste marble powder increases in the mixing ratio. The experimental findings revealed that the waste marble powder can be successfully used as 10% of the partial replacement of cement. Increasing the waste marble powder ratio by more than 10% can significantly decrease the capacity of the beams, especially when longitudinal reinforcement ratio is high. The influence of waste marble as partial replacement on the capacity decreases as the longitudinal reinforcement ratio decreases. Therefore, 10%–20% marble waste can be utilized as a replacement for cement when the longitudinal reinforcement ratio is close to the balanced ratio and more than 20% waste marble ratio should be avoided for any cases.

Dynamic response analysis of a building structure subjected to ground shock from a tunnel explosion

Abstract: Dynamic responses of a multi-storey building without or with a sliding base-isolation device for ground shock induced by an in-tunnel explosion are numerically analyzed. The effect of an adjacent tunnel in between the building and the explosion tunnel, which affects ground shock propagation , is considered in the analysis. Different modeling methods, such as the eight-node equal-parametric finite element and mass-lumped system, are used to establish the coupling model consisting of the two adjacent tunnels, the surrounding soil medium with the Lysmer viscous boundary condition, and the multi-storey building with or without the sliding base-isolation device. In numerical calculations , a continuous friction model, which is different from the traditional Coulomb friction model, is adopted to improve the computational efficiency and reduce the accumulated errors. Some example analyses are subsequently performed to study the response characteristics of the building and the sliding base-isolation device to ground shock. The effect of the adjacent tunnel in between the building and the explosion tunnel on the ground shock wave propagation is also investigated. The final conclusions based on the numerical results will provide some guidance in engineering practice.