No abstract

The procedure of estimating the RC moment-resisting frames under blast loading using a multi-mode adaptive pushover (MADP) analysis is investigated in the current study. The main advantage of the proposed procedure is the combination of the multi-mode and adaptive pushover analysis approaches, which has not been done in the past for blast loadings. To investigate the efficiency of the proposed approach, several RC moment-resisting frames (RC-MRFs) of the 4-, 8-, and 20-storey are considered in the study. For a better comparison, the conventional modal pushover analysis (MPA), nonlinear response history analysis (NRHA), and the proposed approach are considered in the simulations. To this end, various influential parameters including the lateral force, floor displacement, storey drift, storey drift ratio, etc. are considered. For all models, the first three mode shapes were considered in the analysis procedure, while for the case of 20 storey RC-MRF, the torsional effect is included as well. The results indicated that the proposed MADP procedure has adequate accuracy and efficiency to estimate the blast loading demand on RC-MRFs.

No abstract

No abstract

Unpredictable threat and danger may occur in a structural system due to blast loading. Long-span spatial structures are very practical and common in airport terminals, exhibition centers, stadiums, and other public buildings. For high-rise and multi-story structures, horizontal pressure plays a major role in the level of damage to a structure, whereas long-span structures may be influenced by both horizontal and vertical pressure. In the current study, the applicability of lead rubber bearing (LRB) has been evaluated on a low-rise, long-span structure. The analysis is carried out by using the MATLAB Simulink platform. The simulation results indicate that the base isolation system which is usually adopted for seismic control of structures can adequately reduce the structural responses under blast loadings.

Shelter is a basic need for living creatures. The shelter should be safe and secure. The damage of the shelter occurs due to natural hazards and manmade activities. Natural hazards such as earthquake, volcanic eruptions, landslides, flood, etc. Manmade activities may be accidental or intentional. Accidental activities include, internal explosions such as chemical reactions occurring at nuclear power plants, mining, rock cutting etc, gas explosions leakage etc. Hence while designing the structure, additional precautions and considerations should be taken to resist the unpredictable load. Boatload is a dynamic and impulse loads. The earth load occurs in seconds, In the height of the structures force are distributed and is proportion to mass concentrations, the blast load occurs in milli seconds that is one thousand shorter than the earthquake load and magnitude and locations of the blast load rather than mass the force is concentrated. In the present study Five storey structural system exposed to blast load is considered. MATLAB simulation technique is used in the analysis of the Five storey structural The load is acting on the structural system are calculated. Base isolations method is one the recent method is used to reduce the response of the structural system. The semi active control system is used in the analysis. The response is reduced by considerable amount by using Base isolation.

In order to increase the efficiency of the structures to resist seismic excitation, combinations of inerter, negative stiffness, and tuned mass damper are used. In the present work, the optimum tuning frequency ratio and damping of the tuned mass negative stiffness damper-inerter (TMNSDI) for the base-isolated structure were determined by employing the numerical searching technique under filtered white-noise earthquake excitation and stationary white noise. The energy dissipation index, the absolute acceleration, and the relative displacement of the isolated structure were considered as the optimum parameters, obtained by their maximization. Evaluations of base-isolated structures with and without TMNSDI under non-stationary seismic excitations were investigated. The efficiency of the optimally designed TMNSDI for isolated flexible structures in controlling seismic responses (pulse-type, and real earthquakes) were evaluated in terms of acceleration and displacement. A dynamic system was used for deriving the tuning frequency and tuned mass negative stiffness damper inerter (TMNSDI) for white noise excitation by using explicit formulae of the curve fitting method. The proposed empirical expressions, for design of base-isolated structures with supplementary TMNSDI, showed lesser error. Fragility curve results and story drift ratio indicate reduction in seismic response by 40% and 70% in base-isolated structure using TMNSDI.

Shelter is a basic need for living creatures. The shelter should be safe and secure. The damage of the shelter occurs due to natural hazards and manmade activities. Natural hazards such as earthquake, volcanic eruptions, landslides, flood, etc. Manmade activities may be accidental or intentional. Accidental activities include, internal explosions such as chemical reactions occurring at nuclear power plants, mining, rock cutting etc, gas explosions leakage etc. Hence while designing the structure, additional precautions and considerations should be taken to resist the unpredictable load. Boat load and earthquake load are dynamic, impulse loads. The earthquake load occurs in seconds, In the height of the structures force are distributed and is proportion to mass concentrations, blast load occurs in milli seconds compare to seismic load. In the present study SDOF system exposed to blast load is considered. MATLAB simulation technique is used in the analysis of the SDOF system. The SDOF system consists of Front wall, rear wall and Roof. The load is acting on the structural system are calculated by using analytical method. Base isolations method is one the recent method is used to reduce the response of the structural system under impact load. The semi active control system is used in the analysis. The response is reduced by considerable amount by using Base isolation and MR Damper.