Reliable Seismic Structural Analysis Using Interval Ground Motion

Vol.2 No.1

Year : 2013

Issue : Mar-May

Title : Reliable Seismic Structural Analysis Using Interval Ground Motion

Author Name : Mehdi Modares, Adam Venezia

Synopsis :

Abstract: Seismic analysis is an essential procedure to design a structure subjected to ground motion. However, throughout conventional seismic analysis, the structure is subjected to a limited number of recorded earthquake excitations. Moreover, the presence of variations and uncertainties in the recorded excitations within a single, and among different earthquakes is not considered in current seismic analysis procedures. One methods of quantifying the impreciseness and uncertainty is the interval or unknown-but-bounded representation. In this work, a new computationally feasible method for seismic structural analysis with interval uncertainty in the response spectrum is developed, which is capable of obtaining the bounds on the structure’s dynamic response. Using this method, first, the response spectra from various recorded earthquakes are combined in order to construct an interval function referred to as an interval response spectrum. Then, the response spectrum analysis is performed using the developed interval response spectrum, and the bounds of the dynamic response of the structure are obtained. This computationally feasible method shows that calculating the bounds on the dynamic response does not require an iterative procedure such as Monte-Carlo simulation. Numerical example problems, which illustrate the developed algorithm, are presented, along with a comparison of solutions obtained by Monte-Carlo simulation.

Study Of Engineering Properties Of Recycled Concrete Aggregate Concrete

Vol.2 No.1

Year : 2013

Issue : Mar-May

Title : Study Of Engineering Properties Of Recycled Concrete Aggregate Concrete

Author Name : PRAMOD GUPTA, RITESH BHATIA

Synopsis :

A series of experiments were conducted on two grades of concrete namely M25 and M40 with three nominal replacement ratios of 0%, 25% and 50% using recycled concrete aggregates (RCA). The RCA concrete was obtained using a new mix design in which the residual mortar content of the recycled aggregates was considered as a part of sand in the new concrete. For the six mixes, tests were conducted to determine the engineering properties of the RCA concrete and the results were compared to that of the natural aggregate concrete. A total of 72 specimens were cast and tested. The tests conducted included Slump, Non-destructive testing, Compressive strength, Splitting tensile strength and Elastic modulus. Based on the investigations it was found out that the proposed method gave comparable results to that of the concrete made of natural aggregates. Compressive strength, UPV, Rebound Hammer and Elastic modulus values were established to be more than that of the natural aggregate concrete while Slump and Splitting tensile strength were lesser.

Experimental and Analytical Comparison of RC Beam Strengthened with GFRP Strip

Vol.2 No.1

Year : 2013

Issue : Mar-May

Title : Experimental and Analytical Comparison of RC Beam Strengthened with GFRP Strip

Author Name : Hanmant Jadhav, Sachin Matade

Synopsis :

This study presents experimental performance and modes of failure of reinforced concrete (RC) beam strengthened with externally (bottom side) bonded glass fiber reinforced polymer (GFRP) strip. Experimental results compared with presenting finite element modeling of R C beam using ANSYS software. The finite elements model uses a discrete approach to reinforced concrete and three dimensional layered elements to model the fiber reinforced polymer (FRP) composites. The comparison is made for load deflection curve at midspan and mode of failure. The result obtained from finite element analysis was calculated at same location as the experimental test of the beams and accuracy of was compared. The load–deflection curve from finite element analysis is good agreement with the experimental results.

Mechanics of reinforced flyash slopes: A qualitative review

Vol.2 No.1

Year : 2013

Issue : Mar-May

Title : Mechanics of reinforced flyash slopes: A qualitative review

Author Name : Harvinder Singh

Synopsis :

Flyash-a waste by product-is proving a versatile material for the geotechnical use despite its low shearing strength. Past research has demonstrated its potential use in construction of embankments/slopes, filling of low land area etc. It is, now, a well documented fact that use of reinforcing element(s) in flyash slopes and other applications proves beneficial in enhancing its load carrying capacity. In this article, it has been tried to present the mechanics behind this phenomenon and a set of forces working, silently, inside the reinforced flyash/soil mass/slopes that become responsible for strength enhancement of the system. It will help readers to visualise reinforced-flyash system in term of forces and develop simplified analytical expressions governing the behaviour of reinforced slopes.

Behaviour Of Waste Plastic Fibre Reinforced Concrete Produced By Conventional Aggregates And Recycled Aggregates Under Alkaline Environment - An Experimental Investigation

Vol.2 No.1

Year : 2013

Issue : Mar-May

Title : Behaviour Of Waste Plastic Fibre Reinforced Concrete Produced By Conventional Aggregates And Recycled Aggregates Under Alkaline Environment - An Experimental Investigation

Author Name : Prahallada M.C, Prakash K.B

Synopsis :

The addition of fibres into concrete has been found to improve several of its properties like tensile strength, cracking resistance, impact, wear and tear, ductility, fatigue resistance etc. Many types of fibres like steel fibres, carbon fibres, GI fibres, glass fibres, asbestos fibres etc. can be used in fibre reinforced concrete. Waste plastics can also be used as fibres. The disposal of waste plastic is resulting in environmental pollution. Plastic is a non-biodegradable material, and it neither decays nor degenerates in water or in soil. On the other hand it pollutes the water and soil. Plastic if burnt releases many toxic gases, which are very dangerous to health. Such plastics can be used in concrete in the form of fibres to impart some additional desirable qualities to the concrete. This paper presents the results of waste plastic fibre reinforced concrete (WPFRC) produced from recycled aggregates subjected to alkali attack. The different percentages waste plastic fibre used in the experimentation are 0%, 0.5% , 1%, 1.5%, 2%, 2.5% and 3% with an aspect ratio of 50.The results are compared with the waste plastic fibre reinforced concrete (WPFRC) produced from granite aggregates

Analysis Of Supplemental Dampers With Base Isolated RC Frame

Vol.1 No.4

Year : 2013

Issue : Dec-Feb

Title : Analysis Of Supplemental Dampers With Base Isolated RC Frame

Author Name : SETIA, Isha Verma

Synopsis :

In this paper a typical five-storied reinforced concrete plane frames with full isolation are analyzed, assuming two ground types namely rock and moderately soft soil. These two ground types are combined with fundamental vibration periods of 2, 3 and 4 seconds respectively in a high-risk seismic region with the overall isolation system. The isolation systems are made of in-parallel high-damping laminated-rubber bearings and supplemental viscous dampers. Real accelerograms at El Centro 1940 are considered and analysis is carried out with SAP 2000 Version 12 using time history analysis. It is concluded that a supplemental viscous damping at the base is appropriate for controlling the isolator displacement, so avoiding overly large isolators and it is found that displacement will reduce in both the soil conditions; also displacement is less for higher vibration period and a comparison is also made for a base isolated structure with and without supplemental damper.

Analysis Of Skew Deck Slab Bridge By Analytical Methods

Vol.1 No.4

Year : 2013

Issue : Dec-Feb

Title : Analysis Of Skew Deck Slab Bridge By Analytical Methods

Author Name : Bikram Kesharee Patra, Rajesh Kumar, Veerendra Kumar

Synopsis :

Bridges and culverts form important parts of a rail or road or any other type of communication network and the major part of the project of the cost of the project goes into the construction of these structures. In order to cater to high speeds and more safety requirements of the traffic, modern highways are to be straight as far as possible and this has required the provision of increasing number of skew bridges. In brief the study includes the behavior of skew slab bridges with respect to support reaction and deflection of the slab under standard IRC 70R wheeled loading. The modeling of the slab is done by using both Finite element method (FEM) and Grillage method and results are compared.

Bearing Capacity Improvement In Soils Using Waste Tire Rubber Fibers

Vol.1 No.4

Year : 2013

Issue : Dec-Feb

Title : Bearing Capacity Improvement In Soils Using Waste Tire Rubber Fibers

Author Name : Sanjeev Naval, Arvind Kumar , Bansal

Synopsis :

A series of laboratory model tests has been carried out on a model strip footing to investigate the use of waste tire fiber as reinforcement to increase the bearing capacity of soil. Fiber content and depth of reinforcement at relative density 60% are considered to be the main parameters in this paper. The fiber aspect ratio of 12.5 (length = 25mm and width =2mm) was selected. The thickness of reinforcement was kept as 0.5B, 1B, 1.5B and 2B (B is the width of the footing) and four different fiber contents of 0.25%, 0.50%, 0.75% and 1.0% by weight were selected. It has been found that Bearing Capacity Ratio of soil is improved with addition of waste tire fibers at all fiber contents and thicknesses of reinforcement. A maximum value of 1.64 has been found at a fiber content of 0.75% and thickness of reinforcement 1.5B.

Soil Structure Interaction Analysis of Pipe-Rack Structure

Vol.1 No.4

Year : 2013

Issue : Dec-Feb

Title : Soil Structure Interaction Analysis of Pipe-Rack Structure

Author Name : Anand Gharad, Sonparote

Synopsis :

For the purpose of carrying different fluids to its operating units, generally a pipe rack structure having pipes of various sizes laid on it is used in an industrial refinery plant. Sudden opening or closing of pipe valves leads to water hammer effect. Also at pipe bends, this phenomenon is prevalent. A soil structure (pipe-rack) interaction is carried out. By coupling the infinite elements (H.R. Yerli, B. Temel and E.Kiral 1998) with standard finite elements, an ordinary finite element procedure is used for simulation of wave propagation in an unbounded foundation due to external forces. Example studied here indicates that the present approach can be useful for analyzing the transient response of soil-structure interaction problems.

Structural System Degradation Due to High Temperature Arising from Fire

Vol.1 No.4

Year : 2013

Issue : Dec-Feb

Title : Structural System Degradation Due to High Temperature Arising from Fire

Author Name : Jamshid Mohammadi, Jiahong (Joanne) Zuo

Synopsis :

Among major effects of high temperatures on structural materials include a dramatic change in thematerial behavior and a reduction in the load resistance capacity. In a structural system, the high temperatures from fire along with the changes occurredto the material properties and behavior may affect the system's integrity and capability to supportloads. As the fire persists in a building, structural components suffer a gradual degradation processthat may eventually lead to structural collapse. From the serviceability point of view, a building isconsidered a loss once fire spreads to a major portion of it regardless of whether structural collapseoccurs or not. However, the collapse prevention is especially important to the safety of fire fighterswho stay around or inside the building until the fire is completely contained. In this regard, animportant design consideration is how to treat the collapse issue in a design code. At the presenttime, fire protection coating remains as the only safeguard against fire in buildings. No specificguidelines exist to address design strategies to reduce the risk of collapse in buildings during fire.In an effort to clarify on design issues for buildings subject to high temperature arising from fire,this paper presents the results of an investigation into the behavior of structures subject to hightemperatures during fire. Floor systems made up of reinforced concrete slabs with or withoutintermediate beams were investigated under application of a loading that consisted of dead load andfire exposure. The effect of high temperature on material strength and behavior; creep and crackingin concrete; formation of localized failures; and structural degradation resulting from loss of stiffnesswere investigated using a nonlinear finite element analysis. The analysis simulated the loadingprocess and followed the step-by-step structural degradation of floor systems until a predeterminedcollapse criterion was reached. The results revealed a dramatic loss of structural stiffness after atemperature increase of about 400-500 ° C. The paper also describes the significance of fire loadsin structural analysis and design. Issues pertinent to design include: (1) prevention; and (2) designfor safe performance in a fire. These issues as related to a performance-based design code arereviewed and discussed.

Experimental Study of Effect of Part Replacement of Concrete Mix Ingredients on Specific Heat of Concrete

Vol.1 No.3
 

Year: 2012

 
Issue: Sep-Nov

Title : Experimental Study of Effect of Part Replacement of Concrete Mix Ingredients on Specific Heat of Concrete  

Author Name : Navneet Raheja, Nitin Gupta

  

Synopsis :

With the rise in global warming and increasing environmental imbalances, it is becoming essential to find a viable alternative to replace the conventional concrete mix ingredients. The aim of this research was to check the use of waste material as the concrete ingredients and check the impact of same with regards to strength and specific heat of concrete. This paper presents the mix design analysis, compressive strength results and specific heat results for concrete mixes prepared with part replacement of various different materials. The results and conclusion are noted at the end of the paper for future studies.

Stress Strain Behavior of Steel Fibre Based Concrete In Compression

Vol.1 No.3

Year: 2012

 
Issue: Sep-Nov

Title : Stress Strain Behavior of Steel Fibre Based Concrete In Compression  

Author Name : Tantary M. A, Upadhyay A , Prasad J  

Synopsis : 

Steel fibre based concrete is now being increasingly used in different structural applications, including buildings, bridges, pavements etc. complete stress strain curve of the material is therefore essentially needed for the analysis and design of structures. In this study an experimental investigation was carried out to generate the complete stress strain curve for fibre concrete, containing crimped steel fibres. Four types of crimped steel fibres with aspect ratio of 33.5, 36, 45 and 80 respectively, were used in four different volume fractions (0.5, 1.0, 1.5, 2.0 %) in four different concrete mixes. The vital parameters of fibre concrete namely peak stress, strain at peak stress, toughness and the nature of stress strain curve was studied. A simple analytical model was proposed for stress- strain diagram of steel fibre concrete in uni-axial compression. The model was compared with experimental results and a good agreement was noticed between the two.

Computational Benchmarks in Simulation of Cyclic Performance of Steel Connections Using Three Dimensional Nonlinear Finite Element Method

Vol.1 No.3

Year: 2012

 
Issue: Sep-Nov

Title : Computational Benchmarks in Simulation of Cyclic Performance of Steel Connections Using Three Dimensional Nonlinear Finite Element Method  

Author Name : Mohammad Razavi, Roozbeh Kiamanesh, Ali Abolmaali  

Synopsis : 

The presented manuscript is intended to introduce accurate computational benchmarks to predict the hysteresis behavior of beam-column steel connections by means of a 3D non-linear finite element analysis.In this study, element type, inelastic material behavior,bolts pre-tensioning, and contact properties between different components of connections are discussed. Incremental nonlinear analysis takes into account all three types of nonlinearities including material, geometry, and contact properties in predicting moment-rotation hysteresis loops. A series of full-scale structural tests are performed to validate the results obtained from the finite element analyses. This study shows that cost efficient numerical analysis simulation is capable of replacing full-scale tests for steel connections.

Progressive Collapse Level of Analysis Capacity Evaluation of a Retrofit Scheme

Vol.1 No.3

Year: 2012

 
Issue: Sep-Nov

Title : Progressive Collapse Level of Analysis Capacity Evaluation of a Retrofit Scheme

Author Name: James M. Portea, Jeffrey Laman

Synopsis:

The General Services Administration, Department of Defense, and the National Institute of Standards and Technology have all published and continuously maintained new building design guidelines to lower potential for progressive collapse. In addition, the analysis procedures prescribed by these guides cover a range of options or levels; however, the progressive collapse guidelines focus primarily on new construction. Therefore, research is needed to identify and investigate the effectiveness of novel retrofit methods for mitigating progressive collapse of existing buildings through the available analysis levels. The primary objective of the current study was to investigate and compare the outcomes of four levels of analysis: linear-elastic static analysis (3D); nonlinear static analysis; and dynamic nonlinear analysis (2D and 3D) and to establish an analysis methodology for investigating steel buildings retrofit concepts. The retrofit scheme investigated was devised to improve the progressive collapse resistance of a 5-story steel building subjected to sudden, exterior column loss. Results showed that an a-value of 2 generally leads to highly conservative estimates in the results from 5-story models that did not fail at the progressive collapse design load combination. For the 5-story models that failed at the recommended static load combination, the ratio of peak dynamic end moments to static end moments are only comparable because the full static load was not reached before failure, thus also pointing to a conservative a-value. An assessment of the dynamic amplification factor yielded values of 1.4 to 1.6. A less conservative a-value cannot be specified based on the results of this study alone, but the analysis results indicate that for certain buildings, predictions on performance after column loss that are based on a static analysis with an a-value of 2 may be overly conservative. Although the retrofit did not significantly improve the performance of the 5-story building with moment frames in two directions, the retrofit increased the load-carrying capacity of the model without a moment frame orthogonal to the exterior bay. In this case, the retrofit was more effective because the interior beams on each floor, which would otherwise rotate freely if the cables were not in place, participate in resisting some of the floor loads.

An acoustic emission methodology for protecting the structural integrity of composite pressure vessels using neural networks

Vol.1 No.3

Year: 2012

 
Issue: Sep-Nov

Title: An acoustic emission methodology for protecting the structural integrity of composite pressure vessels using neural networks

 

Author Name: Sasikumar.T Thangaswamy, S.Rajendra Boopathy , K.M.Usha , E.S.Vasudev , S. Albert Singh

Synopsis:

Prior prediction of burst pressure of the composite pressure vessels well before its failure would be a complimentary method in the area of composite characterization. In this proposed research, an attempt was made to predict the failure pressure of  the composite pressure vessels. A series of five identical GFRP (Glass Fiber Reinforced Plastics) pressure vessels were monitored with an acoustic emission (AE) system, while proof testing them up to 50% of their theoretical burst pressure. Back propagation neural network models were generated for the prior prediction of burst pressure of the composite pressure vessels. Three different networks were developed with the peak amplitude distribution data of acoustic emission collected up to 30%, 40% and 50% of the theoretical burst pressures. Amplitude frequencies of AE data recorded from three bottles in the training set and their corresponding burst pressures were used to train the networks. Only the amplitude frequencies of the remaining two bottles were given as input to get the output burst pressures from the trained networks. The neurons present in the multi-hidden layers of the networks were able to map the patterns of failure present in the AE data. The results of three independent networks were compared, and it was found that the network trained with more AE data had better prediction performance. Prior prediction of burst pressures of the composite pressure vessels at low proof testing level may serve to avoid significant fiber failures and the associated structural integrity degradation.

Computational Benchmarks in Simulation of Cyclic Performance of Steel Connections Using Three Dimensional Nonlinear Finite Element Method

Vol.1 No.3

Year: 2012

 
Issue: Sep-Nov

Title : Computational Benchmarks in Simulation of Cyclic Performance of Steel Connections Using Three Dimensional Nonlinear Finite Element Method  

Author Name : Mohammad Razavi, Roozbeh Kiamanesh, Ali Abolmaali  

Synopsis : 

The presented manuscript is intended to introduce accurate computational benchmarks to predict the hysteresis behavior of beam-column steel connections by means of a 3D non-linear finite element analysis.In this study, element type, inelastic material behavior,bolts pre-tensioning, and contact properties between different components of connections are discussed. Incremental nonlinear analysis takes into account all three types of nonlinearities including material, geometry, and contact properties in predicting moment-rotation hysteresis loops. A series of full-scale structural tests are performed to validate the results obtained from the finite element analyses. This study shows that cost efficient numerical analysis simulation is capable of replacing full-scale tests for steel connections.

Reinforced Beam Column Corner Joints: Analytical and Experimental Study

Vol.1 No.2

Year: 2012

Issue: Jun-Aug

Title : Reinforced Beam Column Corner Joints: Analytical and Experimental Study   

Author Name: Manpreet Kaur, Roshan Lal                      

Synopsis:   

Beams and columns are the back bone of every structure. The principles of detailing and structural behavior are well established for simple structural members such as beams and columns. On the other hand, the detailing, strength and behavior of corner joints, especially those subjected to opening bending moments have not been conclusively investigated. The present work has, therefore, been planned to investigate the behavior of reinforced concrete corner joints with three detailing arrangements subjected to opening bending moment. The objective of this study is to investigate and identify the detailing system promising best structural performance and also to analytically analyze the selected detailing system by using finite element software ANSYS. Concrete is represented by eight nodded element and the reinforcement is represented by two nodded bar element embedded in the concrete elements. Newton-Raphson’s method is employed for the non-linear solution algorithm and a displacement criterion is adopted for checking the convergence of the solution. There is a good agreement between analytical and experimental results.

 

  

   

 

  

 

Non-Linear Transient Vibration Analysis of plates using Modified Linearization Technique

Vol.1 No.2

Year: 2012

Issue: Jun-Aug

Title: Non-Linear Transient Vibration Analysis of plates using Modified Linearization Technique   

Author Name: Rajesh Kumar   

Synopsis:   

A new numerical technique known as the multi-step transversal linearization (MTL), which is developed within a finite element framework is presented for non-linear transient behavior of isotropic and stiffened plates. In the MTL approach, the non-linear parts of the vector fields are converted to a set of equivalent and conditional forcing terms. These forcing terms are so constructed that the linearized vector field remains identical with the original one at a chosen set of discretization points distributed spatially across the domain of the problem. In the present work, Lagrangian interpolation functions are used to semi-discretize the non-linear part of the operator over the spatial domain. The conditionally linearized vector field thus constructed is transversal to the original vector field at all points of discretization. These operations finally result in a set of non-linear ordinary differential equations for the solution vector, which are solved using Newmark integration technique.

  

   

 

  

 

Studies On Plastic Mixed Concrete With Conventional Concrete

Vol.1 No.2

Year: 2012

Issue: Jun-Aug

Title : Studies On Plastic Mixed Concrete With Conventional Concrete   

Author Name: S.Elavenil, Akarsh M.R, S.Saravanan Subramanian.M   

Synopsis:    

Large quantity of waste plastic could be disposed in an environmental friendly manner. Currently, most researches are focused on determining a good way to eliminate waste by using it as alternative material in the applications of civil and industrial engineering. The waste plastic materials could be powdered and mixed with the concrete and used for fabrication of structural elements. Advanced composites such as fiber reinforced plastics (FRP) are promising and competitive materials that have great potential for use in high value added applications due to their superior characteristics in terms of high stiffness, low density and water absorption, high tensile strength, corrosion resistance and being used in a number of applications. The main aim of this study is to find out an environmental friendly way of disposing waste plastic by reusing principle and to study the behavior of plastic mixed concrete. In this study, the effective ways to reutilize the plastic waste particles as filler is analyzed. The strength characteristics of concrete containing recycled waste plastic material are determined.

  

   

 

  

 

Factors Important In Developing Regional Steel Corrosion Models

Vol.1 No.2

Year: 2012

Issue: Jun-Aug

Title : Factors Important In Developing Regional Steel Corrosion Models   

Author Name: Meghan O’ Dea, Frank C. Graham, Richard H. McCuen   

Synopsis:   

Existing models for predicting long-term corrosion rates are generally power models with exposure time as the independent variable, with separate models for steel type and environment (i.e., urban, rural, marine). An international data base, with data from eight countries (Belgium, France, Germany, Great Britain, Japan, South Africa, Sweden, and the U.S.), was analyzed to examine the effects of exposure time, sample replication, sample size, steel type, the angle and direction of exposure, and the environment. Four steel types were included in the data: A588, A242, copper, and carbon. The results indicate that a global model would not provide accurate predictions, but it was possible to regionalize data for central Europe. Replication of samples was shown to be important for some types of steels in urban and marine environments, but not important for rural environments. The duration of exposure is very important, with some exposure durations being much more important than others. North-facing specimens were shown to corrode more than those facing south, and vertical specimens corroded more than those exposed at an angle of 30°. The amount of corrosion varied with steel type, but less with the country in which the data were collected. These results indicate that corrosion model accuracy can be improved by accounting for these other factors.

 

   

 

  

 

Rehabilitation of Damaged Reinforced Concrete Structure –A Case Study

Vol.1 No.2

Year: 2012

Issue: Jun-Aug

Title : Rehabilitation of Damaged Reinforced Concrete Structure –A Case Study   

Author Name: Hanmant Jadhav, S.N. Patil   

Synopsis:   

This paper presents an assessment of damages caused due to deterioration of concrete and corrosion of reinforcement on account of leakage, ageing and environmental factors through non destructive tests1.The pre and post evaluation of rehabilitation was carried out through load tests. In this study, a60year old rectangular Reinforced Concrete (RC) water tank built over the terrace of the office building was investigated2. It exhibited some cracks and spalling of concrete at certain locations. Two beams and one column were subjected to corrosion of reinforcement and deterioration of concrete. During its service life, the maintenance and repair work of the tank was carried out periodically. Damaged beams and column were repaired by providing new reinforcement with cement grouting and polymer mortar. The deflections in the beam were measured at each stage of loading and unloading at regular intervals. These deflections were found within permissible limits and structural members were restored for their functional requirements3.

 

   

 

  

 

Seismic Analysis And The Influence Of Zone Factor Of A Multi Storey Hospital Building – A Case Study

Vol.1 No.1

Year: 2012

Issue: Mar-May

Title: Seismic Analysis And The Influence Of Zone Factor Of A Multi Storey Hospital Building – A Case Study   

Author Name: K. Subramanian, M.V. Subramanyam   

Synopsis:   

Earthquake on 26th January 2001 in Gujarat clearly demonstrated the earthquake vulnerability of India. Almost more than 60% of our land is vulnerable to earthquake of magnitude more than 7. This leads to the professionals to carry out the research on seismic forces that influence on the structures. This paper presents a detailed case study of an upcoming Ten Storey Hospital building analyzed in ETABS using Response Spectrum analysis of IS 1893 (Part1):2002. The proposed structural system for the hospital building consists of conventional beam, column and slab system with lift walls and walls around staircase acting as shear wall. Lateral Stability is provided by shear walls and columns. The upcoming building is proposed to construct in the Zone III region. Importance factor of 1.5 is considered for the structure considering its functionality. The case study discuss on the influence of various zone factors and the codal provisions, when the same building to be located in different regions. Ductile systems are taken in the study, where inelastic analysis procedures effectively account for several sources of force reduction. The earthquake ground acceleration in each direction is given as a digitized response-spectrum curve of pseudo- spectral acceleration response versus period of the structure. The peak response quantities such as member forces, displacements, storey forces, storey shears and base reactions shall be combined as per Complete Quadratic Combination method. The accidental eccentricity is given as direct input in all floor diaphragms. The dynamic analysis results such as modal participating mass ratios, response spectrum base reaction, storey shears, storey displacements and storey drifts are discussed in detail. Animated results of the displacement due to all modes along with their respective time period are displayed for more understanding of the structural behavior. First and Second modes are found to be in translation and third mode is of torsional mode, which is an acceptable solution to proceed with detailed design.

  

 

   

 

  

 

Finite Element Analysiss Of Composite Cylindrical Shells With And Without Cutouts

Vol.1 No.1

Year: 2012

Issue: Mar-May

Title: Finite Element Analysiss Of Composite Cylindrical Shells With And Without Cutouts   

Author Name: Siva Konda Reddy, Ch.Srikanth , G.Sandeep Kumar   

Synopsis:   

Laminated composite thin cylindrical shells are most widely used structural forms in Aerospace and Missile applications. These structures may experience axial compression loads in their longevity and yield to buckling. Furthermore, these structures usually have disruptions, such as cutouts, which may have adverse effects on their stability and  buckling loads of laminated cylinders can strongly depend on the stacking sequence & number of layers in a laminate. This paper investigates the effect of stacking, number of layers and size & positioning of cutouts on bucking load of a laminated cylindrical shell. ANSYS software is been used for analysis of cylindrical shells