bluuebunny/crossref_metadata_2025 huggingface dataset:
Dynamic Response Control of Stiffened Plate with Hole in Stiffener: A Novel Concept of Additional Open Branched Stiffeners
Authors: Bakshi S. , Sarkar A. , Chakraborty S.
Published: December 2022

Modern day structures have found diverse applications of stiffened plates in civil, mechanical, aerospace, marine and offshore engineering. The stiffeners, mainly in the form of beams in these stiffened plates are often exposed to unfavourable environmental and service loads, inducing localized damage to the stiffeners. Sometimes, holes are deliberately made on the stiffeners for passing service pipes, cables etc. Both of the events cause localised loss of stiffness, finally affecting the global dynamic performances. One of the practised techniques to recover the lost stiffness and to safeguard the damaged site is to introduce enclosed prismatic stiffeners around the hole. However, this often fails to critically readjust the localised stiffness loss. A constructive alternate to alleviate such situation, is to provide open branched configurations of additional stiffeners within the near vicinity of the damage. The present research work deals with the demonstration of the suitability of the above solution through numerical modelling of dynamic behaviour of a rectangular isotropic stiffened plate with a central longitudinal stiffener using finite element software ANSYS. The damage, represented equivalently as a circular cut-out in the stiffener, is considered to be located arbitrarily. Free vibration characteristics viz. natural frequencies and mode shapes of the plate in undamaged and damaged conditions have been determined by solving eigenvalue problem employing Block Lanczos algorithm. Various configurations of open-branched stiffeners around the circular cut-out, placed at specified locations have been explored. The sensitivities of relevant geometric parameters, such as the distance of the branching from the damage site, orientations of the branching etc. indicate that it is possible to design a system of open branched stiffeners around a damaged site of a stiffener to keep the overall dynamic responses practically unchanged. Such idea of branched stiffener is novel and has potential practical applications towards damage mitigation of various engineering infrastructures.
Empirical Validation of Free Vibration of Sagging Cables
Authors: Kumar Pankaj , Ganguli Abhijit , Benipal GurmailS.
Published: December 2022

Sagging cables lack unique natural state, but possess unique equilibrium state under sustained loads. However, for the purpose of predicting their dynamic response, the static equilibrium state of heavy cables under self-weight is assumed to be their initial state. The theory of sagging elastic cables presented earlier by the Authors pertains to weightless cables carrying nodal masses apart from static and inertial forces. For applying the proposed theory for sagging heavy cables, the cable is divided into ten segments of equal length. The initial equilibrium configuration of the cable fixed at both the ends is determined by the weights of these lumped nodal masses applied at ten nodes with one end fixed. The stiffness matrix of the cable is determined from tangent configurational flexibility matrix and tangent elastic flexibility matrix of twenty degree of freedom system. The cable tied at both the ends in an equilibrium state is set into motion by releasing it at one end. The theoretically predicted response of the cable is compared with the experimental data from the two investigations. The first experimental investigation by Fried pertains to the planar undamped vibrations of a sagging elastic cable, in which cable is released from its right end and its configurations are plotted at regular time intervals of 0.001s. In the second investigation by Koh, Zhang and Quek, the configurations of a different cable at regular time intervals of 0.125s during half the vibration cycle is measured. The dynamic tensile force at the fixed end has also been predicted in the latter case. The theoretical prediction of the evolving cable configuration have been found to be compatible with experimental data.
A Comparative Study on Different Types of Passive Energy Dissipating Devices
Authors: Kalita Hemanta , Kashyap Upasana , Chetia Nayanmoni
Published: December 2022

Earthquake induced structural vibrations causes fatigue and reduction of performance of the tall steel framed structures. One of the effective ways for improving the seismic performance of a structure is the use of bracings, dampers and isolators. These devices change the stiffness and damping of the structures thereby reducing the seismic vibrations to a great extent. The main objective of this study is to compare the different types of passive energy dissipating devices in a 3 bay 10 storey steel frame building for better seismic response. The frame was modelled in SAP2000® and some of their responses to earthquake such as base shear, maximum joint displacement, inter storey drift were determined and compare during non-linear dynamic time history analysis in SAP2000®.The passive energy dissipating devices used in this study are diagonal bracing, v bracing, cross bracing, rubber base isolator and friction damper. At first a single storied shear frame model was tested in shake table and results obtained from SAP 2000® were compared. The close proximity validated the procedure. It is observed that addition of dampers to the system increases the stiffness to the frame. When compared, displacement for steel frame with dampers is reduced by 80% and that with different bracing systems are reduced up to 78% as compared to bare steel frame. For base isolators, base shear decreases up to 63.33% but an increase in the maximum joint displacement was observed. The comparison of performances of all types of dissipating mechanisms has been presented in the study.
Seismic Response Of Multi-storey Building Using Artificial Neural Network
Authors: Charan Rajshree , Patel Alpesh
Published: December 2022

The different parameters like base shear, drift, and top storey displacement of G+7 building is evaluated by using time history analysis and response spectrum analysis for the purpose of comparative study of both the analyses using MATLAB and an artificial neural network (ANN).
The main objective of present work is to analyse earthquake of different locations like Bhuj, Kobe, Victoria and Elecentro, for time history analysis building is not connected with actuator and it is analysed during seismic motion of building using a MATLAB software. Base shear, drift and top storey displacement is evaluated during this analysis. For response spectrum analysis, first building relates to actuator at top floor. And during seismic motion of building different parameters like base shear, drift and top floor displacement are evaluated using MATLAB software and for evaluation of control force of a design actuator artificial neural network (ANN) is used. From time history analysis, response spectrum analysis test results and graphs for G+7 building it is clear that, when actuator is not connected with building it does not dissipate the energy of seismic motion and base shear of building , drift , and top floor displacement is very high, and in second case when building is connected with actuator at optimal place it gives considerable response during seismic motion of building and base shear of building, drift, and top floor displacement are can considerably reduce using control actuator system.
Soil-Structure Interaction Effects on Seismic Response of Multi-storey Buildings
Authors: Verma Arjit , Pal P. , Gupta Y.K.
Published: December 2022

The effect of soil-structure interaction (SSI) on the seismic responses of multi-storey buildings is investigated. The execution of SSI effects is conducted in two ways viz. Winkler approach and soil continuum approach. Time-history analysis methods are used for the seismic evaluation of parameters like time period, modal mass participation, base shear, lateral displacement, storey drift and inter-storey drift ratio. The present study consists of two parts; one is fixed base analysis i.e. without SSI, and the other is flexible base analysis i.e. with SSI. The buildings are modelled using finite element-based software SAP2000, where the equilibrium equations are solved by Hilber-Hughes-Taylor (HHT) method. A parametric study is performed with existing ground motion and varying numbers of stories to inherit the above parameters' responses. The results obtained from flexible base conditions are compared to those corresponding to fixed base conditions. The study shows that the behaviour of the structure changes under the SSI conditions and it may become vital in some cases; however, ambiguity also subsists with SSI.
Seismic Performance of Coupled Buildings Connected by Yield and SMA Dampers
Authors: Singh P. , Gur S. , Roy K.
Published: December 2022

Efficient attenuation and control of structural vibration during a seismic event is a critical factor for overall safety and serviceability of the adjacent buildings with little clearance between them. Without proper vibration control measures, adjacent buildings may undergo severe pounding and collapse leading to damage of life and property during an earthquake. Use of energy dissipation devices to connect adjacent buildings has been a popular method of vibration control and to stop mutual poundings. Among various available energy dissipation devices, Shape Memory Alloy (SMA) based dampers are getting popularity in recent time. Various studies are performed to show the efficiency of SMAs as passive vibration control device, but a holistic study of SMA dampers for non-linear connected buildings is still missing. Thus, here a comparative study on the efficiency of metallic yield and super-elastic SMA dampers as passive vibration control device is provided, for non-linear connect buildings. In the present study, non-linear dynamic time history analyses are performed to determine the response (peak floor acceleration and displacement, and floor residual displacement). Time history analyses confirm better acceleration and displacement (both peak and residual) control efficiency of SMA dampers over yield dampers. Finally, superiority of the SMA damper over the yield damper is established via parametric study under varying damper, building and ground motion parameters. Over yield damper, SMA damper reduces acceleration by 13 % to 56 %, displacement by 2 % to 47 %, and residual displacement by 15 % to 64 %.
Optimal control of structural vibration using LQG algorithm
Authors: Chaudhuri Payel , Maiti D.K. , Maity Damodar
Published: December 2022

This paper proposes a Linear Quadratic Guassian Design (LQG) with based semi-active control algorithm for vibration reduction of building structures. The controlled damper force required by the structure has been calculated from an MR damper of load capacity 100N. A building frame has been selected to illustrate the performance of the proposed algorithm. Four different earthquake acceleration data has been used as input vibration data to the numerical frame. The proposed method of damping on the frame has been found to be more effective to reduce the structural response significantly in comparison with the conventional tuned liquid column damper. The developed method is efficient in providing the optimum control force required to the frame. Therefore, it minimizes the need of high damping capacity and the number of dampers. As a result, it reduces the cost of maintenance and structural control during earthquakes.
Effective Scheduling and Time Management of Dhamra Railway Project Using Primavera P6
Authors: Rao S.A. , Patel S.B. , Jain P.N. , Patel V.M.
Published: December 2022

Indian construction industry is growing quickly and huge development projects are going on. Most certainly it’s justifiably or in a roundabout way connected with the Indian economy, the speed with which projects complete have appeared to influence the GDP of the country. Appropriate scheduling and planning are substantial in construction projects for decreasing and controlling postponements of the project, while an error in the same causes squandering of a significant quantity of time, capital, resources, and quality. Despite firm principles and policies, the monitoring process may be inefficient because of the practical problems prevailing or rising in the project. An attempt has been made in realizing the practical problems in project execution will contribute to proper recognition of the problem areas and implementing mitigation. The main objectives of this study are to plan, schedule, monitor, and control a railway infrastructure i.e. Dhamra Railway Project, Orissa, India with the help of Oracle Primavera P6 software. The review of various research articles has been performed and twenty-five factors from nine categories are shortlisted for the study and the time factor is considered for analysis. Thereafter, critical time analysis of the project has been performed, listing project activities with duration, their logical relationships, scheduling, and network updating considering factors from the nine categories. The main challenges leading to delays are climate, government approvals, material availability, and the remote project location. Further, project crashing is done by provision of additional labour resources to critical activities and observation can be made that a raise of 21% of labour resources would offer a reduction of 17% of the activity completion time, this trend doesn’t imply that surging the resources directly reduces duration, it will reduce duration but up to the minimum fundamental duration required only.
Mapping of Global Construction Safety Research using Scientometric Approach
Authors: Patel D.A. , Amlani S.B.
Published: December 2022

The construction sector is one of the hazardous sectors across the world. In the Indian construction sector, on an average 38 fatal accidents happen every day. Research on construction safety and improvement of safety performance has been continuing for a few years. It explores multiple areas such as safety performance measurement, safety program, human factors, safety planning, site monitoring, etc. This study followed a three-stage literature review approach summarizing the research domain of construction safety. The science mapping approach consists of both bibliometric analysis and scientometric analysis which are carried out in this study. For the bibliometric analysis, Web of Science (WoS) database has been used while for the scientometric analysis, the Cite-Space software has been used in this study. This study identifies key areas of construction safety management by following by a qualitative discussion on research publications across the globe. It includes information and communication technology in safety management, workers' safety perception and behaviour, safety management system, hazard identification, accident causation, and risk management in safety, safety climate and safety culture. This study helped the authors to prepare the outline of construction safety manual. This paper is useful to academic community and industry practitioners to understand the trend of research in the field of construction safety. Also, the proposed directions for future work could benefit to the new researchers and industry practitioners in enhancing safety performance and improving site 'employees' health and wellbeing.
Dynamic Characterization of Concrete using Split Hopkinson Pressure Bar
Authors: Ganorkar Kavita , Arora Ketan , Gaur Lekhani , Goel M.D. , Chakraborty Tanusree
Published: December 2022

Concrete exhibits brittle behaviour and is weak under tensile and flexural loading. The response of concrete to dynamic loading is of interest in a variety of civilian and military applications. Understanding the response of concrete to impact or explosive loading is important for effective protection of defence and civil structures. The split Hopkinson pressure bar (SHPB) technique has been used widely to measure the dynamic strength enhancement of materials at high strain rates. Although, SHPB technique has been verified for metallic materials, but validity and accuracy of SHPB results for non-metallic, e.g. concrete materials have not been thoroughly studied so far. The present study examines the application of SHPB to determine the dynamic strength of concrete under compressive loading. The aim of this study is to understand the strain rate effect on the ultimate uniaxial compressive strength of concrete in SHPB tests for two different grades of concrete. The behaviour of concrete at strain rates of the order of 200 - 600 per second and pressures up to 0.38 MPa are studied experimentally. The strength of concrete is found to be increased with the increase in strain rates. Further, it is observed that due to the composite microstructure of concrete, deformation and stresses are non-uniform in the concrete specimens.
Axial Deformation of Shells at Higher Strain Rates using Buckling Initiators
Authors: Bhutada S. , Goel M.D.
Published: December 2022

Deformation mode of cylindrical shells and their peak load reduction is of prime importance in impact damage mechanics. In this study, numerical investigation is carried out for triggering mechanism induced in the thin-walled axially compressed short stubby shells, considering the damage occurred in vehicle crash or in any other protective equipment. The shells are studied for their initial buckling response under varying impact velocities for two different triggering configurations. Explicit simulation is carried out using ABAQUS/Explicit® to study the initial buckling of the shells by modelling Split Hopkinson Pressure Bar (SHPB) test setup. Initially, numerical scheme is validated using previously available study. Present analysis is carried out using diamond shaped triggering notches and these are configured in such a way that the shell will deform in particular buckling mode, under the impact of three different velocities i.e. 9 m/s, 20 m/s and 40 m/s. Effect of these notches and their pattern of arrangement on reduction in peak load and energy absorption characteristics are studied. Moreover, comparison is made between commonly used circular hole and diamond notch type cut-outs, in order to study the effect of above said parameters along with the energy absorbed, energy efficiency and specific energy absorption for the shells considered herein. By numerically impacting the shells in SHPB, it is observed that peak load reduction is higher in diamond notched shells as compared to circular hole shells. This was due to the geometry and size of the cut-outs considered in this study. Parameters like peak collapse load, energy absorbed, energy efficiency along with stress concentration around the notch are also observed and studied in this work in order to observe and compare the two shapes of cut-outs.
A Systematic Approach for Analysis of Structure under Blast Load – An Overview
Authors: Saha Shuvra , Mondal Monojit , Karmakar Somnath
Published: December 2022

An explosion is an unwanted phenomenon that may be caused accidentally or intentionally. It may be occurred within or near the structure that causes massive damage to the same. An explosion becomes disastrous when the structural elements collapse partially or totally. Many works have been made to grow the techniques/methods of blast resistance structures. A detailed understanding is required for blast load and its effect on the several structural members in terms of dynamic responses to analyze and design a safe engineering structure. Further, in this article, a comprehensive overview of a systematic approach for the analysis of structure under blast load has been presented. For the computation of blast load, different types of empirical relations are available, which are in the pattern of pressure-time functions. Here, the same is represented concisely with an easier way of understanding. Prediction of blast load by the empirical, semi-empirical, and numerical method has been presented. Modelling of blast load for various numerical simulation techniques and material models are also described here for modelling the advanced structural material that may mitigate the blast response of the structure as per the Hydrocodes.
Naïve Bayesto Machine Learning Approach for Structural Dynamic Complications
Authors: Ramana P.V.
Published: December 2022

Learning is one of the most powerful concepts in artificial intelligence research. It allows a system to learn from its environment and automatically modify its behavior to suit its needs. On par with human champions, the world’s best computer backgammon player is a computer program that learns by playing against itself. The learning algorithm and available data set limit computer learning. Several techniques are available to perform machine learning. Decision trees, the naïve Bayes approach, and the more general Bayes net approach are a few choices. The naïve Bayes approach is an instance of the more general Bayes nets. This paper examines and analyzes the naïve Bayes and decision tree approaches to learning. Various techniques to avoid over-fitting, such as ensemble construction and cross-validation, are also implemented and analyzed. A novel hybrid between the naïve Bayes approach and the decision tree method is presented. The hybrid system produces a spectrum of options that could be used for learning by merely changing parameter values. At one end lies the naïve Bayes approach, while at the other lies the decision tree technique. The proposed hybrid scheme solves the problem of poor naïve Bayes performance in a domain with dependent attributes and the memory consumption problem of the decision tree. One can analyze this idea and show encouraging experimental data that backs the need for such a solution.
Comparative Analysis of Aluminum Alloy 6061-T6 and Mild Steel Tubes in Sacrificial Protection System under Blast Loading
Authors: Goel M.D. , Choudhary N.S. , Panchal Sandeep
Published: December 2022

A sacrificial cladding consist of hollow metal tubes and steel sheet, is proposed in this study to protect a square concrete panel subjected to blast loading. Herein, comparative analysis of aluminum alloy 6061-T6 (Al 6061-T6) and mild steel tubes in sacrificial cladding is done using 3-D non-linear Finite Element (FE) software ABAQUS/Explicit®. Blast load is applied through ConWep program developed by US Army. Simplified Concrete Damage Plasticity (SCDP) model is used to define the material behavior of concrete slabs of thickness 250 mm. Johnson-Cook (J-C) plasticity model is used to model the stress-strain response of Al 6061-T6 and mild steel tubes, reinforcement bars and steel sheet. Diameter (D) and thickness (t) of circular metal hollow tubes are taken from IS1161:1998. Comparative analysis of Al 6061-T6 and mild steel tubes is carried out for blast loading using TNT with scaled distance of 0.425 m/kg1/3. It was observed that mild steel tubes perform better than Al 6061-T6 tubes and save concrete panel from degradation under blast loading.
Comparative Study of Mechanical Properties of Concrete Using Commercially Available Bacterial Strains
Authors: Sarma Swapneel , Hussain Baharul , Begum SharminaAktara , Rabha Ayushman , Gangte DenisL. , Debnath Suman , Konwar Queen , Chetia Nayanmoni
Published: December 2022

Bacteria impregnated concrete is a recent advancement in concrete technology which is being studied extensively by different researchers all around the world. This study aims to study the effect of bacteria on different parameters of concrete and compare the results from compressive test, split tensile test and flexure test with that of a normal mix concrete. The main objective of this research was to study the mechanical properties of concrete upon adding commercially available Bacillus Subtilis (5 billion cells/gm) and laboratory cultured Bacillus Cohnii (105 cells/ml) to the concrete mix. Both the bacterial concretes are mixed with calcium lactate and are cured in Calcium Chloride solution. This particular study confirms that commercially available Bacillus Subtilis imparts better concrete properties compared to laboratory cultured Bacillus Cohnii.
Comparison of compressive strength of cement mortars using an industrial product obtained from three different regions of India
Authors: Dubey Moulshree , Deo S.V. , Ramtekkar G.D.
Published: December 2022

The quest to realize initial strength and develop high strength concrete has increased considerably in recent times. Cement is one among the main sources of environmental impacts of concrete use. it's therefore recognized because the most practical solution to scale back the environmental impacts of concrete, the shortage of cement content. this will be achieved by replacing some of cement with an industrial product like metakaolin. Metakaolin is that the material obtained by calcination of kaolinite at 500 and 800 degrees. Metakaolin (MK), in its applications partial replacement of cement, features a particularly growing role worldwide for technological enhancement thanks to its pozzolanic activity and mainly to realize strength.
This paper portrays the results of an investigation on the utilization of metakaolin (MK) as a complementary cement material. Four metakaolin substitution levels were employed in experimental studies of mortar mixes: 5% 10% 15% and 20% by weight of hydraulic cement. The concise strength of mortar cubes with different levels of metakaolin with different chemical properties obtained from three different regions of India, namely Maharashtra, Gujarat and Tamil Nadu, was compared. The chemical composition of varied metakaolin was obtained by conducting X-ray deflection analysis. Mortar cubes are cast with varying w / b ratios, i.e. 5% to twenty substitution by metakaolin with replacement of cement at 0.30, 0.35, 0.40 and 0.45 w / b ratios. The results depicted that, overall, 20% substitution of metakaolin from Maharashtra, Gujarat and Tamil Nadu significantly increased the compressive strength. At a ratio of 0.45 w / b, Metakaolin from Tamil Nadu achieved initial strength upon 10% replacement of cement by metakaolin.Metakaolin.
A comparison of stress-strain behaviour of conventional and high strength concrete
Authors: Bhonde V. , Fadadu M. , Patel S. , Mungule M. , Iyer K.K.R.
Published: December 2022

Strength performance of concrete is characterized by its compressive strength, elastic modulus, stiffness and energy absorption capacity. Stress strain behaviour of concrete encompasses information on all these parameters, and is thus one of the most vital data to assess its overall performance. The present study utilizes the stress strain response, as a tool, to compare the relative variation in performance of conventional and high strength concrete. Two set of mix compositions (viz., M40 and M80 grade concrete) have been designed. The designed compositions are checked for their target strength by performing load controlled tests on 28 day cured cube specimens. M40 grade concrete comprises of cement and water as binding material, and fine and coarse aggregates as filler. High strength concrete (M80 grade) is designed with cement, mineral admixture and water as binding material; while the fine and coarse aggregates contribute to the filler material. For high strength concrete, super plasticizer has been added in required proportion to ensure adequate workability. Displacement control tests, with controlled strain rate, have been performed on 28 day cured cube specimens. Variability in pre-peak and post-peak stress strain response is analysed for both conventional and high strength concrete. An average of response over atleast four samples is computed for both the M40 and M80 grade concrete. In present study, the characteristic response is normalized with respect to peak strength to obtain a common reference basis and compared. The comparison is summarized in terms of change in pre-peak response and post-peak ductility. The observed results enable quantification of relative change in performance for M40 and M80 grade of concrete. The results are significant for benchmarking performance of high strength concrete structures with those of conventional concrete structures.
Investigation of Bursting Force In I-Section Post-Tensioned Anchorage Zone
Authors: Jain M.R. , Khapre R.N.
Published: December 2022

In post tensioned concrete beam the high transverse tensile stress is generated and if proper reinforcement is not given, bursting may occur. To study the effect of these stresses and to find bursting stress in end region the analytical study was carried out. In present work the end block of post-tensioned prestressed concrete beam is modelled in finite element based software with eccentric tendons. The bursting zone of beam is evaluated and parametric study was carried out by varying eccentricity, anchorage ratio and web thickness of girder. The 3D modelling was done and results are compared in terms of bursting force. The results are compared with Indian Standard 1343:2012 and inferences are drawn towards the usability of IS code equation of bursting force for I-section.
Base Isolated connected buildings subjected to seismic and blast induced vibrations
Authors: Kangda M.Z. , Bakre S.V.
Published: December 2022

In the present study, the passive control of closely spaced base isolated and fixed base buildings are investigated under the effects of earthquakes and blast induced vibrations. The study advocates the installation of viscous dampers (FVDs) to protect the closely spaced base isolated buildings adjacent to fixed base buildings against seismic and blast excitations. The performance of a five storied base isolated building is reviewed such that time period of isolated building (Tb) is 2.5 sec with isolation damping is assumed as 5% and connected to an adjacent fixed base building such that it has three storey and structural time period 0.5 sec. The effectiveness of damper connected base isolated and fixed buildings is also analyzed for isolation period 2 sec and 3 sec respectively. Nonlinear direct integration method has been adopted to evaluate the performance of fixed base and base isolated structures for connected and unconnected state. The equations of motions are formulated and solved using MATLAB code by Newmark’s average acceleration method. The lead rubber isolators are designed and idealized as Bouc Wen model. A parametric study is also conducted to determine the optimum damper properties for the fixed base buildings and base isolated connected buildings with viscous dampers. Results exhibit the efficiency of viscous dampers in reducing the structural responses of the base isolated buildings. It has been observed that in case of fixed base buildings, the peak responses show an effective reduction in responses. The effectiveness of the passive control technique using viscous dampers in mitigating the bearing displacements of base isolated structures subjected to seismic and blast induced vibrations is also reported.
Nonlinear Finite Element Analysis of Corroded Reinforced Concrete Beams
Authors: Sompura M. , Choudhury T. , Kwatra N.
Published: December 2022

Corrosion in reinforcing bars is a major cause of concern for sustainability of Reinforced Concrete (RC) structures exposed to extreme environmental conditions. Various RC structures, such as bridges and buildings are adversely affected due to the rebar corrosion, reducing its global load carrying capacity and ductility. In order to ensure an earthquake resistant design of any structure, the ductility of structural members is of chief concern. However, corrosion of reinforcing steel in RC members reduces its seismic performance. Thus, for safety and economic viability of any RC structure, an effective maintenance and repair work strategy is necessary. Based on the strong column - weak beam design concept of RC frames, the beams are the first structural members to absorb damage due to earthquake. Thus, to carry out maintenance and repair work, structural health assessment of RC beams considering the effect of reinforcement corrosion is of utmost importance. The present study aims at establishing a relation between the amount of corrosion induced and its effect on the ductility of an RC beam. A 3D Finite Element (FE) model of an RC beam including the effects of corrosion for nonlinear performance assessment has been modelled in ABAQUS. The FE model is validated with past experimental study including the effects of corrosion. Modelling of uniform corrosion in reinforcement bars involves defining the loss of bond between rebars and concrete, inducing spalling stresses on concrete and reduction in the cross-section area of the rebars. Bond-slip model between surface of concrete and reinforcement has been incorporated through cohesive surface. Spalling stress for uniform corrosion is applied in form of outward uniform pressure on the reinforcement and concrete interface. The cracking of cover concrete due to corrosion along with the flexural cracking in concrete due to incremental loading are implemented together in the present study. A comprehensive FE model is developed in order to obtain correct assessment of corroded beams. As observed from the FE model, the failure mechanism of the considered corroded RC beam is observed to be mostly shear failure as the corrosion level increases. Concrete crushing at the center of the RC beam is identified at the failure point of the beam due to corrosion induced damage. Evolution of displacement ductility index with respect to corrosion is determined for an RC beam based on the numerical study. It has been observed that the displacement ductility index of the beam is reduced significantly after considering a corrosion level of about 12%. Hence, the present study is an effort to establish a relation between structural performance of RC beams and level of reinforcement corrosion, which will be useful in proactive maintenance and repair work for corroded RC beams.
Utilization of Plastic Waste (PET Bottles) and Fly Ash in Concrete: A Review
Authors: Paliwal Gopal , Suryawanshi ShiwanandR.
Published: December 2022

Origins of all basic ingredients of concrete are nature and reducing with an increase in the consumption of concrete. It requires finding alternate material that can be utilized in the production of concrete; the revolutionary in the construction industry called green concrete, which is produced by adopting the wastes.
In this study, a review is done on previously reported work for the utilization of fly ash and plastic waste in concrete. Many research works have been studied and it is concluded that the major focus was to evaluate the effect of fly ash and plastic waste on the fresh concrete property such as workability and hardened concrete properties such as compressive strength, flexural strength, split tensile strength; whereas much of durability properties are yet to be studied. Also, the behaviour of the green concrete post-fire exposure has not been dealt so far.
Model reduction technique for Bayesian model updating of structural parameters using simulated modal data
Authors: Sengupta P. , Chakraborty S.
Published: December 2022

An attempt has been made to study the effectiveness of model reduction technique for Bayesian approach of model updating with incomplete modal data sets. The inverse problems in system identification require the solution of a family of plausible values of model parameters based on available data. Specifically, an iterative model reduction algorithm is proposed based on a non-linear optimization method to solve the transformation parameter such that no prior choices of response parameters are required. The modal ordinates synthesized at the unmeasured degrees of freedom (DOF) from the reduced order model are used for a better estimate of likelihood functions. The reduced-order model is subsequently implemented for updating of unknown structural parameters. The present study also synthesizes the mode shape ordinates at unmeasured DOF from the reduced order model. The efficiency of the proposed model reduction algorithm is further studied by adding noises of varying percentages to the measured modal data sets. The proposed methodology is illustrated numerically to update the stiffness parameters of an eight-story shear building model considering simulated datasets contaminated by Gaussian error as evidence. The capability of the proposed model reduction algorithm coupled with Markov Chain Monte Carlo (MCMC) algorithm is compared with the case where only MCMC algorithm is used to investigate their effectiveness in updating model parameters. The numerical study focuses on the effect of reduced number of measurements for various measurement configurations in estimating the variation of errors in determining the modal data. Subsequently, its effects in reducing the uncertainty of model updating parameters are investigated. The effectiveness of the proposed model reduction algorithm is tested for number of modes equal to the number of master DOFs and gradually decrease of mode numbers from the number of master DOFs.
Application of UPV-Instrument in Health Monitoring of Indian Rail Section Using AE Technique
Authors: Kundu Tamal , Pal Apurba , Roy Parikshit , Datta AlokeKumar , Topdar Pijush
Published: December 2022

In present work, buckling analysis of laminated composite plates is carried out using recently proposed higher-order zigzag theory (HOZT). Third order variation of in-plane displacement field is taken across the thickness of the plate. For predicting the behavior efficiently for thick plates, quadratic variation of transverse displacement field is assumed for core layer and constant for face layers. The present theory satisfies inter-laminar transverse shear stress continuity condition at interface along with zero value at top and bottom surface of the plate. In present study, nine-noded finite element having eleven degrees of freedom per node is used. Present model is free from requirement of any kind of penalty function or C-1 condition.
Strength of Cold-Formed Stainless-Steel Corrugated Rectangular Sections under Compression
Authors: Anto Megha , Ramalingam Raghavan , Perumalsamy Jayabalan
Published: December 2022

Provision of intermediate stiffening is an effective method to improve the strength of cold-formed steel compression members without having to increase the outer dimensions of the section. As cold-formed sections can be easily produced in various cross-section profiles, the effect of intermediate stiffening on ultimate load carrying capacity and behavior of structural elements need to be determined. In this study columns with Cold-Formed Stainless-Steel and Corrugated Rectangular Hollow Sections are studied numerically using Finite Element analysis. The column simulation is conducted using ABAQUS software including material nonlinearity and performed with the Static Riks procedure. The objective is to study how providing stiffening in the form of corrugations influences the buckling behavior of these columns. Columns for a range of slenderness ratio with varying cross-section parameters were modelled and compared to identify the influencing parameters. The study showed that buckling strength of columns can be significantly increased by providing corrugations. Corrugations effectively resisted local buckling in columns even with low slenderness ratio. The parameters influencing the buckling behavior are identified as cross-section aspect ratio, corrugation height, corrugation width and minimum radius of gyration of the cross-section. Buckling curves are placed for the corrugated sections based on the numerical analysis, and in relation to the buckling curves provided in design standards. On comparing them with the predictions by Euro Code (EN 1993-1-4 (2006)), it was observed that Euro Code predictions are conservative, which is also seen from the buckling curves shown for the corrugated sections.
Stability Analysis of a Real Life Tilted RCC Over Head Reservoir (Tank) considering Soil-Structure and Fluid-Structure Interaction
Authors: Acharjee Devjit , Bandyopadhyay Srijani , Bandyopadhyay Debasish
Published: December 2022

Tilt and settlement of RCC structures with foundations over alluvial soil of greater Kolkata and surrounding Ganges Flood Basin is a frequent problem with respect to the stability of these structures. The tilt and subsequent distress have a significant effect on the overall stability of the Over Head Reservoirs (Tanks); which also depend on the nature of the supporting soil, Fluid Structure Interaction (FSI). Various NDTs can be performed to assess the condition of the concrete members, but this piecewise assessments may not adequately address the overall stability of the OHRs subjected to various loadings including lateral seismic forces, particularly for a tilted one. Thus, numerical analysis of the tilted OHR is significantly important to assess its overall stability considering its global behaviour. The present numerical study aims to evaluate the effect of the tilt on the overall stability of a real life existing RCC OHR supported on frame staging. The increase in design reinforcement demand and lateral displacement at crown top level are compared to assess the effect of tilt from the Limit State of Collapse and Limit State of Serviceability points of view. The global effect of the tilt is studied based on the changes of its fundamental period of vibrations of the OHR. Subsequently, Pushover analysis is also performed to evaluate the effect of the tilt on the various parameters e.g. base shear capacity, inelastic displacement at crown top level, global ductility. The vulnerability index based on the pushover analysis results are also compared to ascertain the effect of the tilt. Soil-Structure Interaction and Fluid-Structure Interaction have been duly considered in the Finite Element models on SAP2000 platform to study the effect of tilt on the OHR stability. It is found that the tilt plays a great role on the overall stability and safety of the frame staging OHR, which further get aggravated due to softer supporting soil and considering Fluid-Structure Interactions. The proposed stability analysis of this case study seems to have a great potential for its practical application in safety evaluation and retrofit of existing OHRs subjected to tilt.
Effect of Aerodynamic Modification on ‘V’ plan Shaped Tall Building Under Wind Excitation
Authors: Bhattacharya Satadru , Dalui SujitKumar
Published: December 2022

Advanced high-rise buildings with peculiar cross-sectional plan is the major challenging concern to all structural engineers as well as researchers due to variation in dynamic wind response. Irregular shaped tall buildings are vulnerable to wind force due to height and nonuniformity of the structure. In the present study, the principal objective is to investigate the significant role of the aerodynamic modification of the building model to reduce the aerodynamic effect of wind force on ‘V’ plan shaped high-rise building and to modify aerodynamic design criteria accordingly. Various cases have been made by considering different local modification like corner chamfered and corner rounded of ‘V’ plan shaped building model. The angle between the limbs is 90° which remain unchanged. The percentage is gradually increased from 5% to 20% of the total plan area with 5% regular increment for both chamfered and rounded corner. Wind incident angle is increased from 0° to 90° with 30° regular interval for each case. Computational Fluid Dynamics (CFD) is the basis of method to perform the numerical simulation of ‘V’ plan shaped building with local modifications such as corner chamfered, corner rounded which is similar wind environment as in urban terrain. Grid convergence study is performed to improve the accuracy of result by adopting very finer meshing of Computational Domain. Pressure coefficient of each face, force coefficient, velocity variation, pressure variation on each face is obtained by numerical analysis. Further, a comparison has been made with basic ‘V’ plan shaped tall building model without any modification to study the effectiveness of aerodynamic modification on wind-induced response of ‘V’ plan shaped building exposed to different wind incidence angle and observations have been made on the suitability of aerodynamic modification based on the numerical result.
Study on Gust Factor Method for Multi-purpose Cyclone Shelter
Authors: Chande R.A. , Shah A.J.
Published: December 2022

Cyclone is one of the major threat hovering over Indian coastal regions and need for safe shelter is now utmost to save the endangered population from the hazardous outcomes. Also, to save the structure from deterioration a multi-purpose cyclone shelter will be most affordable during emergency and nonemergency period. Present Indian Codal provisions underlines that the flexible structures ought to be designed by peak wind approach in addition to mean wind approach related to gust factor method and severe of the two is to be designed as design load. Use of gust factor method for high-rise structures is common but for low-rise important structures there are a few researches available. In this study two G + 1 and G + 2 storey models are considered and analyzed using IS 456:200, IS 1893: 2016 and IS 875: 2015 with gust factor method. Guidelines from Indian government for cyclone shelters and school buildings are followed and loadings from Indian Standards code are considered. This study aims to provide information on behavior of low-rise structure of a school building by changing height of the structures. For that MS-Excel spreadsheet was prepared for gust factor method and 80 models were prepared using ETABS software by changing height of column members, adding a new floor above existing structure, changing seismic zones and increasing basic wind speed. Various parameters such as storey force, base shear and maximum top displacement are scrutinized for above mentioned cases for four structures of different heights.
Investigation of Variable Wind Loads and Shape Accuracy of Reflectors in Parabolic Trough Collector
Authors: Natraj . , Reddy K.S. , Rao B.N.
Published: December 2022

Concentrated solar power is the technology involving reflectors which reflects the solar radiation and concentrates the radiations onto a receiver which absorbs the solar radiation and rises the temperature of the fluid flowing through it and the fluid is further used for process heating or power generation. Solar parabolic trough is the most established technology among the concentrated solar power technologies. For the optimization of the technology it is important to optimize the parabolic trough collectors from structural point of view as even gravity load is observed to cause a substantial effect on the shape of the reflector. Shape accuracy of the reflector is measured in terms of slope deviation. The slope deviation induced due to gravity and wind loads causes a change in optical and thermal efficiencies. The paper presents the study on pressure distribution at the surface of parabolic trough collector under different wind velocity, angle of attack of wind and orientation of the trough. Further, the pressure values over the trough surface are used to estimate the shape errors for the surface of the trough.
Static Analysis of thin Rectangular Plate Resting on Elastic Foundation Using Modified Vlasov Model
Authors: Dutta AshisKumar , Bandyopadhyay Debasish , Mandal JagatJyoti
Published: December 2022

A four-nodded rectangular plate bending element based on Kirchhoff theory resting on elastic foundation using modified Vlasov model. For evaluate the two soil parameter for Vlasov foundation the modulus of elasticity and Poisson ratio of the soil is assumed constant from top surface to the top of bottom rigid base. All the deformation stiffness matrix of plate and subsoil are evaluated using finite element method. A Matlab code is developed and convergence study is carried out and then some realistic cases of plate under static load on elastic foundations are solved to determine the static response. The results, thus obtained, are compared, with the available results obtained by other researchers. It behaves extremely well for thin plates and convergence rate is high.