Search results for: concrete-filled tubular structures

Authors: Yassine Sadji

Abstract:

Some architectural conditions required some shapes often lead to an irregular distribution of masses, rigidities, and resistances. The main object of the present study consists in estimating the influence of the irregularity both in plan and in elevation which presenting some structures on the dynamic characteristics and his influence on the behavior of this structures. To do this, it is necessary to make apply both dynamic methods proposed by the RPA99 (spectral modal method and method of analysis by accélérogramme) on certain similar prototypes and to analyze the parameters measuring the answer of these structures and to proceed to a comparison of the results.

Keywords: irregularity, seismic, response, structure, ductility

Procedia PDF Downloads 279

Authors: Joshi Manisha, Shivaram, Anand Vinekar, Tanya Susan Mathews, Yeshaswini Nagaraj

Abstract:

Retinopathy of prematurity (ROP) is abnormal blood vessel development in the retina of the eye in a premature infant. The principal object of the invention is to provide a technique for detecting demarcation line and ridge detection for a given ROP image that facilitates early detection of ROP in stage 1 and stage 2. The demarcation line is an indicator of Stage 1 of the ROP and the ridge is the hallmark of typically Stage 2 ROP. Thirty Retcam images of Asian Indian infants obtained during routine ROP screening have been used for the analysis. A graphical user interface has been developed to detect demarcation line/ridge and to extract ground truth. This novel algorithm uses multilevel vessel enhancement to enhance tubular structures in the digital ROP images. It has been observed that the orientation of the demarcation line/ridge is normal to the direction of the blood vessels, which is used for the identification of the ridge/ demarcation line. Quantitative analysis has been presented based on gold standard images marked by expert ophthalmologist. Image based analysis has been based on the length and the position of the detected ridge. In image based evaluation, average sensitivity and positive predictive value was found to be 92.30% and 85.71% respectively. In pixel based evaluation, average sensitivity, specificity, positive predictive value and negative predictive value achieved were 60.38%, 99.66%, 52.77% and 99.75% respectively.

Keywords: ROP, ridge, multilevel vessel enhancement, biomedical

Procedia PDF Downloads 409

Authors: Woo Young Jung, Sung Min Park, Ho Young Son, Viriyavudh Sim

Abstract:

This study presents a way to reduce earthquake damage and emergency rehabilitation of critical structures such as schools, high-tech factories, and hospitals due to strong ground motions associated with climate changes. Regarding recent trend, a strong earthquake causes serious damage to critical structures and then the critical structure might be influenced by sequence aftershocks (or tsunami) due to fault plane adjustments. Therefore, in order to improve seismic performance of critical structures, retrofitted or strengthening study of the structures under aftershocks sequence after emergency rehabilitation of the structures subjected to strong earthquakes is widely carried out. Consequently, this study used composite material for emergency rehabilitation of the structure rather than concrete and steel materials because of high strength and stiffness, lightweight, rapid manufacturing, and dynamic performance. Also, this study was to develop or improve the seismic performance or seismic retrofit of critical structures subjected to strong ground motions and earthquake aftershocks, by utilizing GFRP-Corrugated Infill Panels (GCIP).

Keywords: aftershock, composite material, GFRP, infill panel

Procedia PDF Downloads 334

Authors: Hasan Husnu Korkmaz, Serra Zerrin Korkmaz

Abstract:

Earthquakes are the natural disasters that threat several countries. Turkey is situated on a very active earthquake zone. During the recent earthquakes, thousands of people died due to failure of reinforced concrete structures. Although Turkey has a very sufficient earthquake code, the design and construction mistakes were repeated for old structures. Lack of the control mechanism during the construction process may be the most important reason of failure. The quality of the concrete and poor detailing of steel or reinforcement is the most important headings. In this paper, the reasons of failure of reinforced concrete structures were summarized with relevant photos. The paper is beneficial for civil engineers as well as architect who are in the process of construction and design of structures in earthquake zones.

Keywords: earthquake, reinforced concrete structure, failure, material

Procedia PDF Downloads 365

Authors: Sabina Hublova, Kristyna Hrabova, Petr Cikrle

Abstract:

Sustainable development and preservation of existing buildings are becoming increasingly important worldwide. In order to reduce the amount of CO2 emissions in the air and to reduce the amount of waste from building structures, we can predict an increasing demand for maintenance of some existing buildings in the future. The use of modern diagnostic methods, which allow detailed determination of the properties of structures, the identification of critical points, could be the great importance for the better assessment of existing structures. Non-destructive methods could be one of the options. From these methods, ultrasonic appears to be a highly perspective method, thanks to which we are able to identify critical points of an element or a structure. The experiment will focus on the use of electroacoustic methods for defectoscopy in reinforced concrete columns.

Keywords: sustainability, defectoscopy, ultrasonic method, non-destructive methods, electroacoustic methods

Procedia PDF Downloads 168

Authors: R. K. Apalowo, D. Chronopoulos, V. Thierry

Abstract:

There exist a wide range of failure modes in composite structures due to the increased usage of the structures especially in aerospace industry. Moreover, temperature dependent wave response of composite and layered structures have been continuously studied, though still limited, in the last decade mainly due to the broad operating temperature range of aerospace structures. A wave finite element (WFE) and finite element (FE) based computational method is presented by which the temperature dependent wave dispersion characteristics and interaction phenomenon in composite structures can be predicted. Initially, the temperature dependent mechanical properties of the panel in the range of -100 ◦C to 150 ◦C are measured experimentally using the Thermal Mechanical Analysis (TMA). Temperature dependent wave dispersion characteristics of each waveguide of the structural system, which is discretized as a system of a number of waveguides coupled by a coupling element, is calculated using the WFE approach. The wave scattering properties, as a function of temperature, is determined by coupling the WFE wave characteristics models of the waveguides with the full FE modelling of the coupling element on which defect is included. Numerical case studies are exhibited for two waveguides coupled through a coupling element.

Keywords: finite element, temperature dependency, wave dispersion characteristics, wave finite element, wave scattering properties

Procedia PDF Downloads 308

Authors: Dmitriy Kuptsov

Abstract:

Tree data structures, such as binary or in general k-ary trees, are essential in computer science. The applications of these data structures can range from data search and retrieval to sorting and ranking algorithms. Naive implementations of these data structures can consume prohibitively large volumes of random access memory limiting their applicability in certain solutions. Thus, in these cases, more advanced representation of these data structures is essential. In this paper we present the design of the compact version of ternary tree data structure and demonstrate the results for the experimental evaluation using static dictionary problem. We compare these results with the results for binary and regular ternary trees. The conducted evaluation study shows that our design, in the best case, consumes up to 12 times less memory (for the dictionary used in our experimental evaluation) than a regular ternary tree and in certain configuration shows performance comparable to regular ternary trees. We have evaluated the performance of the algorithms using both 32 and 64 bit operating systems.

Keywords: algorithms, data structures, succinct ternary tree, per- formance evaluation

Procedia PDF Downloads 160

Authors: Juliet Udoudom

Abstract:

Complement ordering principles of natural language phrases (XPs) stipulate that Head terms be consistently placed phrase initially or phrase-finally, yielding two basic theoretical orders – Head – Complement order or Complement – Head order. This paper examines the principles which determine complement ordering in English V- and N-bar structures. The aim is to determine the extent to which complement linearisations in the two phrase types are consistent with the two theoretical orders outlined above given the flexible and varied nature of natural language structures. The objective is to see whether there are variation(s) in the complement linearisations of the XPs studied and the implications which such variations hold for the inter-language syntax of English and Ibibio. A corpus-based approach was employed in obtaining the English data. V- and -N – bar structures containing complement structures were isolated for analysis. Data were examined from the perspective of the X-bar and Government – theories of Chomsky’s (1981) Government-Binding format. Findings from the analysis show that in V – bar structures in English, heads are consistently placed phrase – initially yielding a Head – Complement order; however, complement linearisation in the N – bar structures studied exhibited parametric variations. Thus, in some N – bar structures in English the nominal head is ordered to the left whereas in others, the head term occurs to the right. It may therefore be concluded that the principles which determine complement ordering are both Language – Particular and Phrase – specific following insights provided within Phrasal Syntax.

Keywords: complement order, complement–head order, head–complement order, language–particular principles

Procedia PDF Downloads 348

Authors: A.D. García-Soto, Miguel Jaimes, J.G. Valdés-Vázquez, A. Hernández-Martínez

Abstract:

The seismic reliability of two-degree-of-freedom (2DOF) systems with and without supplemental damping are computed. The used records are scaled from realistic records using standard incremental dynamic Analysis (IDA). The total normalized shear base is computed for both cases using different scaling factors, and it is considered as the demand. The seismic reliability is computed using codified design to stipulate the capacity and, after some assumptions, applying the first-order reliability method (FORM). The 2DOF considered can be thought as structures with non-linear behavior, with and without seismic protection, subjected to earthquake activity in Mexico City. It is found that the reliability of 2DOF structures retrofitted with supplemental damper at its first story is generally higher than the reliability of 2DOF structures without supplemental damping.

Keywords: 2DOF structures, IDA, FORM, seismic reliability

Procedia PDF Downloads 134

Authors: Mohammad A. Bani-Khaled

Abstract:

In this work we use the Discrete Proper Orthogonal Decomposition transform to characterize the properties of coupled dynamics in thin-walled beams by exploiting numerical simulations obtained from finite element simulations. The outcomes of the will improve our understanding of the linear and nonlinear coupled behavior of thin-walled beams structures. Thin-walled beams have widespread usage in modern engineering application in both large scale structures (aeronautical structures), as well as in nano-structures (nano-tubes). Therefore, detailed knowledge in regard to the properties of coupled vibrations and buckling in these structures are of great interest in the research community. Due to the geometric complexity in the overall structure and in particular in the cross-sections it is necessary to involve computational mechanics to numerically simulate the dynamics. In using numerical computational techniques, it is not necessary to over simplify a model in order to solve the equations of motions. Computational dynamics methods produce databases of controlled resolution in time and space. These numerical databases contain information on the properties of the coupled dynamics. In order to extract the system dynamic properties and strength of coupling among the various fields of the motion, processing techniques are required. Time- Proper Orthogonal Decomposition transform is a powerful tool for processing databases for the dynamics. It will be used to study the coupled dynamics of thin-walled basic structures. These structures are ideal to form a basis for a systematic study of coupled dynamics in structures of complex geometry.

Keywords: coupled dynamics, geometric complexity, proper orthogonal decomposition (POD), thin walled beams

Procedia PDF Downloads 418

Authors: Alireza Taghdiri, Sara Ghanbarzade Ghomi

Abstract:

Nowadays, steel structures are used for not only common buildings but also high-rise construction and wide span covering. The advanced methods of construction as well as the advanced structural connections have a great effect on architecture. However a better use of steel structural systems will be achieved with the deep understanding of steel structures specifications and their substantial advantages. On the other hand, the steel structures face to the different environmental factors such as air flow which cause erosion and corrosion. With the time passing, the amount of these steel mass damages and also the imposed stress will be increased. In other words, the position of erosion in steel structures related to existing stresses indicates that effective environmental conditions will gradually decrease the structural resistance of steel components and result in decreasing the durability of steel components. In this paper, the durability of different steel structural components is evaluated and on the basis of these stress, architectural strategies for designing the system and the components of steel structures is recognized in order to achieve an optimum life cycle.

Keywords: durability, bending stress, erosion in steel structure, life cycle

Procedia PDF Downloads 560

Authors: Mahmoudi Noureddine, Kaou Abdellah

Abstract:

Energy absorption is a major requirement for automotive structures. Although crashworthy structures of composite based glass fiber have exhibited energy absorption greater than similar at other composites structures, the crush process in many cases is accompanied by fracture, rather than by plastic deformation. The crash experiments show that the tubes are crushed in progressive manner start from one end of the tubes and delamination takes place between the layers. To better understand details of the crash process, ABAQUS finite element code is used.

Keywords: Energy absorption, crash, PEHD

Procedia PDF Downloads 498

Authors: Kahil Amar, Boukais Said, Kezmane Ali, Hannachi Naceur Eddine, Hamizi Mohand

Abstract:

The principle of the seismic performance evaluation methods is to provide a measure of capability for a building or set of buildings to be damaged by an earthquake. The common objective of many of these methods is to supply classification criteria. The purpose of this study is to present a method for assessing the seismic performance of structures, based on Pushover method, we are particularly interested in reinforced concrete frame structures, which represent a significant percentage of damaged structures after a seismic event. The work is based on the characterization of seismic movement of the various earthquake zones in terms of PGA and PGD that is obtained by means of SIMQK_GR and PRISM software and the correlation between the points of performance and the scalar characterizing the earthquakes will be developed.

Keywords: seismic performance, pushover method, characterization of seismic motion, harmfulness of the seismic

Procedia PDF Downloads 383

Authors: Vladislav A. Nazukin, Valery G. Avgustinovich, Vakhtang V. Tsatiashvili

Abstract:

The most important part of modern lean low NOx combustors is a premixer where swirlers are often used for intensification of mixing processes and further formation of required flow pattern in combustor liner. Swirling flow leads to formation of complex eddy structures causing flow perturbations. It is able to cause combustion instability. Therefore, at design phase, it is necessary to pay great attention to aerodynamics of premixers. Analysis based on unsteady CFD modeling of swirling flow in production combustor swirler showed presence of large number of different eddy structures that can be conditionally divided into three types relative to its location of origin and a propagation path. Further, features of each eddy type were subsequently defined. Comparison of calculated and experimental pressure fluctuations spectrums verified correctness of computations.

Keywords: DES simulation, swirler, vortical structures, combustion chamber

Procedia PDF Downloads 352

Authors: Djamal Hamadi, Oussama Temami, Abdallah Zatar, Sifeddine Abderrahmani

Abstract:

The analysis and design of thin shell structures is a topic of interest in a variety of engineering applications. In structural mechanics problems the analyst seeks to determine the distribution of stresses throughout the structure to be designed. It is also necessary to calculate the displacements of certain points of the structure to ensure that specified allowable values are not exceeded. In this paper a comparative study between displacement and strain based finite elements applied to the analysis of some thin shell structures is presented. The results obtained from some examples show the efficiency and the performance of the strain based approach compared to the well known displacement formulation.

Keywords: displacement formulation, finite elements, strain based approach, shell structures

Procedia PDF Downloads 419

Authors: Kuo-Cheng Liu

Abstract:

In the latest research efforts, the structures of the image in the spatial domain have been successfully analyzed and proved to deduce the visual masking for accurately estimating the visibility thresholds of the image. If the structural properties of the video sequence in the temporal domain are taken into account to estimate the temporal masking, the improvement and enhancement of the as-sessing spatio-temporal visibility thresholds are reasonably expected. In this paper, the temporal characteristics of human perception to the change in block structures on the time axis are analyzed. The temporal characteristics of human perception are represented in terms of the significant variation in block structures for the analysis of human visual system (HVS). Herein, the block structure in each frame is computed by combined the pattern masking and the contrast masking simultaneously. The contrast masking always overestimates the visibility thresholds of edge regions and underestimates that of texture regions, while the pattern masking is weak on a uniform background and is strong on the complex background with spatial patterns. Under considering the significant variation of block structures between successive frames, we extend the block structures of images in the spatial domain to that of video sequences in the temporal domain to analyze the relation between the inter-frame variation of structures and the temporal masking. Meanwhile, the subjective viewing test and the fair rating process are designed to evaluate the consistency of the temporal characteristics with the HVS under a specified viewing condition.

Keywords: temporal characteristic, block structure, pattern masking, contrast masking

Procedia PDF Downloads 413

Authors: Bazla Manzoor, Aqsa Yasin

Abstract:

Pakistan is the country which is progressing by leaps and bounds through agricultural and industrial growth. The main area, which presents the largest income rate through industrial activities, is Faisalabad from the Province of Punjab. Faisalabad’s main occupations include agriculture and industry. As these sectors i.e. agriculture and industry is developing day by day, they are earning much income for the country and generating thousands of job vacancies. On one hand the city, i.e. Faisalabad is on the way of development through industrial growth, while on the other hand this industrial growth is producing a bad impact on the environment. In return, that damaged environment is affecting badly on the people and built environment. This research is chiefly based on one of the above-mentioned factors i.e. adverse environmental impacts on the built structures. Faisalabad is an old city, therefore; it is having many old structures especially from British Era. Many of those structures are still surviving and are functioning as the government, private and public buildings. However, these structures are getting in a poor condition with the passage of time due to bad maintenance and adverse environmental impacts. Bad maintenance is a factor, which can be controlled by financial assistance and management. The factor needs to be seriously considered is the other one i.e. adverse environmental impacts on British Era structures of the city because this factor requires controlled and refined human activities and actions. For this reason, a research was required to conserve the British Era structures of Faisalabad so that these structures can function well. The other reason to conserve them is that these structures are historically important and are the heritage of the city. For doing this research, literature has been reviewed which was present in the libraries of the city. Department of Environment, Town Municipal Administration, Faisalabad Development Authority and Lyallpur Heritage Foundation were visited to collect the existing data available. Various British Era structures were also visited to note down the environmental impacts on them. From all the structures “Clock Tower,” was deeply studied as it is one of the oldest and most important heritage structures of the city because the earlier settlements of the city were planned based on its location by The British Government. The architectural and environmental analyses were done for The Clock Tower. This research study found the deterioration factors of the tower according to which suggestions have been made.

Keywords: lyallpur, heritage, architecture, environment

Procedia PDF Downloads 302

Authors: Beciri Mohamed Walid

Abstract:

Some architectural conditions required some shapes often lead to an irregular distribution of masses, rigidities and resistances. The main object of the present study consists in estimating the influence of the irregularity both in plan and in elevation which presenting some structures on the dynamic characteristics and his influence on the behavior of this structures. To do this, it is necessary to make apply both dynamic methods proposed by the RPA99 (spectral modal method and method of analysis by accelerogram) on certain similar prototypes and to analyze the parameters measuring the answer of these structures and to proceed to a comparison of the results.

Keywords: structure, irregular, code, seismic, method, force, period

Procedia PDF Downloads 310

Authors: Ghada Badr, Arwa Alturki

Abstract:

The biological function of an RNA molecule depends on its structure. The objective of the alignment is finding the homology between two or more RNA secondary structures. Knowing the common functionalities between two RNA structures allows a better understanding and a discovery of other relationships between them. Besides, identifying non-coding RNAs -that is not translated into a protein- is a popular application in which RNA structural alignment is the first step A few methods for RNA structure-to-structure alignment have been developed. Most of these methods are partial structure-to-structure, sequence-to-structure, or structure-to-sequence alignment. Less attention is given in the literature to the use of efficient RNA structure representation and the structure-to-structure alignment methods are lacking. In this paper, we introduce an O(N2) Component-based Pairwise RNA Structure Alignment (CompPSA) algorithm, where structures are given as a component-based representation and where N is the maximum number of components in the two structures. The proposed algorithm compares the two RNA secondary structures based on their weighted component features rather than on their base-pair details. Extensive experiments are conducted illustrating the efficiency of the CompPSA algorithm when compared to other approaches and on different real and simulated datasets. The CompPSA algorithm shows an accurate similarity measure between components. The algorithm gives the flexibility for the user to align the two RNA structures based on their weighted features (position, full length, and/or stem length). Moreover, the algorithm proves scalability and efficiency in time and memory performance.

Keywords: alignment, RNA secondary structure, pairwise, component-based, data mining

Procedia PDF Downloads 458

Authors: Mustafa Aydın, Ali Murat Sunbul

Abstract:

Hierarchical or nested data structures usually are seen in many research areas. Especially, in the field of education, if we examine most of the studies, we can see the nested structures. Students in classes, classes in schools, schools in cities and cities in regions are similar nested structures. In a hierarchical structure, students being in the same class, sharing the same physical conditions and similar experiences and learning from the same teachers, they demonstrate similar behaviors between them rather than the students in other classes.

Keywords: hierarchical linear modeling, nested data, hierarchical structure, data structure

Procedia PDF Downloads 652

Authors: Banu Hatice Gürcüm, Pınar Arslan, Mahmut Yalçın

Abstract:

From the oldest production methods with yarns used to weave, knit, braid and knot to the newest production methods with fibres used to stitch, bond or structures of innovative technologies, laminates, nanoparticles, composites or 3D printing systems, textile industry advanced through materials, processes and context mostly within the last five decades. The creative momentum of fabric like 3D printed structures have come to the point of transforming as for the newest form of textile applications. Moreover, pioneering studies on the applications of 3D Printing Technology and Additive Manufacturing have been focusing on fashion and apparel sector from the last two decades beginning with fashion designers. After the advent of chain-mail like structures and flexible micro or meso structures created by SLS rapid manufacturing a more textile-like behavior is achieved. Thus, the primary aim of this paper is to discuss the most important properties of traditional fabrics that are to be expected of future fabrics. For this reason, this study deals primarily with the physical properties like softness, hand, flexibility, drapability and wearability of 3D Printed structures necessary to identify the possible ways in which it can be used instead of contemporary textile structures, namely knitted and woven fabrics. The aim of this study is to compare the physical properties of 3D printed fabrics regarding different rapid manufacturing methods (FDM and SLS). The implemented method was Material Driven Design (MDD), which comprise the use of innovative materials according to the production techniques such as 3D printing system. As a result, advanced textile processes and materials enable to the creation of new types of fabric structures and rapid solutions in the field of textiles and 3D fabrics on the other hand, are to be used in this regard.

Keywords: 3D printing technology, FDM, SLS, textile structure

Procedia PDF Downloads 339

Authors: S. A. Hashemi, A. Khoshraftar

Abstract:

This paper presents the influence of the vertical seismic component on the non-linear dynamics analysis of three different structures. The subject structures were analyzed and designed according to recent codes. This paper considers three types of buildings: 5-, 10-, and 15-story buildings. The non-linear dynamics analysis of the structures with assuming elastic-perfectly-plastic behavior was performed using Ram Perform-3D software; the horizontal component was taken into consideration with and without the incorporation of the corresponding vertical component. Dynamic responses obtained for the horizontal component acting alone were compared with those obtained from the simultaneous application of both seismic components. The results show that the effect of the vertical component of the ground motion may increase the axial load significantly in the interior columns and consequently, the stories. The plastic mechanisms would be changed. The P-Delta effect is expected to increase. The punching base plate shear of the columns should be considered. Moreover, the vertical component increases the input energy when the structures exhibit inelastic behavior and are taller.

Keywords: inelastic behavior, non-linear dynamic analysis, steel structure, vertical component

Procedia PDF Downloads 317

Authors: Pan Rui, Ma Jun, Zhao Caiqi, Wang Guangda

Abstract:

With the development of the tourism and religion,more and more large statue structures are adopted to build all over the world.For instance,the GuanYin statue with three plane reaches 108 meters high in HaiNan province in China.These statue structures belong to typical high-rise Building. However,the geometry sculpt of statues are complicated .The irregular shape makes these structures more complicated in force analysis than those normal standard tall buildings.In this paper,the Liu Bang Statue which is located at XuZhou in China.

Keywords: large statue structure, special-shaped steel, GuanYin statue, China

Procedia PDF Downloads 395

Authors: Jerome Michael J. Sadullo, Jamaica Lois A. Torres, Trisha Muriel T. Valino

Abstract:

In the Philippines, Central Luzon is one of the regions at high risk in terms of volcanic eruption. In fact, last June 15, 1991, which were the Mount Pinatubo has erupted, the most affected provinces were Zambales, Olangapo, Pampanga, Tarlac, Bataan, Bulacan and Nueva Ecija. During the Mount Pinatubo eruption, Castillejos, Zambales, has recorded the most significant damage to both commercial and residential structures. In this study, the researchers aim to determine and analyze the various impacts of ashfall on roof structures in Concepcion, Tarlac, during the event of a volcanic eruption. In able for the researcher to determine the sample size of the study, they have utilized Cochran's sample size formula. With the computed sample size, the researchers have gathered data through the distribution of survey forms, utilizing public records, and picture documentation of different roof structures in Concepcion, Tarlac. With the data collected, Chi-squared goodness of fit was done by the researcher in order to compare the data collected from the observed N (Concepcion, Tarlac) and expected N (Castillejos, Zambales). The results showed that when it comes to the roof constructions material used in Concepcion, Tarlac and Castillejos, Zambales. Structures in Concepcion, Tarlac were most likely to suffer worse when another eruption happens compared to the structures in Castillejos, Zambales. Yet, considering the current structural statuses of structure in Concepcion Tarlac and its location from Mount Pinatubo, they are less likely to experience ashfall.

Keywords: risk assessment, Concepcion, Tarlac, Volcano Pinatubo, roof structures, ashfall

Procedia PDF Downloads 106

Authors: L. Richter, J. Lübkemann, P. Nyhuis

Abstract:

In order to remain competitive in what is a turbulent environment; businesses must be able to react rapidly to change. The past response to volatile market conditions was to introduce an element of flexibility to production. Nowadays, what is often required is a redesign of factory structures in order to cope with the state of constant flux. The Institute of Production Systems and Logistics is currently developing a descriptive and causal model for the redesign of plant structures as part of an ongoing research project. This article presents the first research findings attained in devising this model.

Keywords: change driven factory redesign, factory planning, plant structure, flexibility

Procedia PDF Downloads 270

Authors: Hassan Gomar, Shahin Bagheri, Nader Keyvan, Mozhdeh Shirinzadeh

Abstract:

Air-Cooled Condenser (ACC) platform structures are the most complicated and principal structures in power plants and other industrial parts which need to condense the low-pressure steam in the cycle. Providing large spans for this structure has great merit as there would be more space for other subordinate buildings and pertinent equipment. Moreover, applying methods to reduce the overall cost of construction while maintaining its strength against severe seismic loading is of high significance. Tabular spatial structures and composite frames have been widely used in recent years to satisfy the need for higher strength at a reasonable price. In this research program, three different structural systems have been regarded for ACC steel platform using Special Concentrate Braced Frames (SCBF), which is the most common system (first scheme), modular spatial frames (second scheme) and finally, a modified method applying Concrete Filled Steel Tabular (CFST) columns (third scheme). The finite element method using Sap2000 and Etabs software was conducted to investigate the behavior of the structures and make a precise comparison between the models. According to the results, the total weight of the steel structure in the second scheme decreases by 13% compared to the first scheme and applying CFST columns in the third scheme causes a 3% reduction in the total weight of the structure in comparison with the second scheme while all the lateral displacements and P-M interaction ratios are in the admissible limit.

Keywords: ACC, SCBF frames, spatial structures, CFST frames

Procedia PDF Downloads 197

Authors: Anna Jeon, Seung-Ho Han, Je-Hun Lee

Abstract:

The aim of this study was to determine the location and distribution pattern of neurovascular structures superior and inferior to the clavicle by detailed dissection. Fifteen adult non-embalmed cadavers with a mean age of 71.5 years were studied. For measurements, the most prominent point of the sternal end of the clavicle (SEC) on anterior view and the most prominent point of the acromial end of the clavicle (AEC) were identified before dissection. A line connecting the SEC and AEC was used as a reference line. The surrounding neurovascular structures were investigated. The supraclavicular nerve was densely distributed at 71.73% on the reference line. Branches of the thoracoacromial artery were located at 76.92%. Branches of subclavian vein were evenly distributed at all sections. The subclavian vein and artery and brachial plexus were located from 31.3% to 57.5%. That area needs caution because major neurovascular structures run underneath the clavicle.

Keywords: clavicle, ORIF, neurovascular structure, anatomical study

Procedia PDF Downloads 163

Authors: Arthi Ganapathy, Rati Tandon, Saroj Kaler

Abstract:

Introduction: A thorough knowledge of variations in lung anatomy is of prime significance during surgical procedures like lobectomy, pneumonectomy, and segmentectomy of lungs. The arrangement of structures in the lung hilum act as a guide in performing such procedures. The normal pattern of arrangement of hilar structures in the right lung is eparterial bronchus, pulmonary artery, hyparterial bronchus and pulmonary veins from above downwards. In the left lung, it is pulmonary artery, principal bronchus and pulmonary vein from above downwards. The arrangement of hilar structures from anterior to posterior in both the lungs is pulmonary vein, pulmonary artery, and principal bronchus. The bronchial arteries are very small and usually the posterior most structures in the hilum of lungs. Aim: The present study aims at reporting the variations in hilar anatomy (arrangement and number) of lungs. Methodology: 75 adult formalin fixed cadaveric lungs from the department of Anatomy AIIMS New Delhi were observed for variations in the lobar anatomy. Arrangement of pulmonary hilar structures was meticulously observed, and any deviation in the pattern of presentation was recorded. Results: Among the 75 adult lung specimens observed 36 specimens were of right lung and the rest of left lung. Seven right lung specimens showed only 2 lobes with an oblique fissure dividing them and one left lung showed 3 lobes. The normal pattern of arrangement of hilar structures was seen in 22 right lungs and 23 left lungs. Rest of the lung specimens (14 right and 16 left) showed a varied pattern of arrangement of hilar structures. Some of them showed alterations in the sequence of arrangement of pulmonary artery, pulmonary veins, bronchus, and others in the number of these structures. Conclusion: Alterations in the pattern of arrangement of structures in the lung hilum are quite frequent. A compromise in knowledge of such variations will result in inadvertent complications like intraoperative bleeding during surgical procedures.

Keywords: fissures, hilum, lobes, pulmonary

Procedia PDF Downloads 223

Authors: Saeed Asiri, Yousuf Z. AL-Zahrani

Abstract:

A new class of support structures, called periodic structures, is introduced in this paper as a viable means for isolating the vibration transmitted from the sea waves to offshore platform structures through its legs. A passive approach to reduce transmitted vibration generated by waves is presented. The approach utilizes the property of periodic structural components that creates stop and pass bands. The stop band regions can be tailored to correspond to regions of the frequency spectra that contain harmonics of the wave frequency, attenuating the response in those regions. A periodic structural component is comprised of a repeating array of cells, which are themselves an assembly of elements. The elements may have differing material properties as well as geometric variations. For the purpose of this research, only geometric and material variations are considered and each cell is assumed to be identical. A periodic leg is designed in order to reduce transmitted vibration of sea waves. The effectiveness of the periodicity on the vibration levels of platform will be demonstrated theoretically. The theory governing the operation of this class of periodic structures is introduced using the transfer matrix method. The unique filtering characteristics of periodic structures are demonstrated as functions of their design parameters for structures with geometrical and material discontinuities; and determine the propagation factor by using the spectral finite element analysis and the effectiveness of design on the leg structure by changing the ratio of step length and area interface between the materials is demonstrated in order to find the propagation factor and frequency response.

Keywords: vibrations, periodic structures, offshore, platforms, transfer matrix method

Procedia PDF Downloads 289

Authors: Muhammad Maqsood, Yasir Nawab, Syed Talha Ali Hamdani

Abstract:

Stretchable fabrics have diverse applications ranging from casual apparel to performance sportswear and compression therapy. Compression therapy is the universally accepted treatment for the management of hypertrophic scarring after severe burns. Mostly stretchable knitted fabrics are used in compression therapy but in the recent past, some studies have also been found on bi-stretch woven fabrics being used as compression garments as they also have been found quite effective in the treatment of oedema. Therefore, the objective of the present study is to compare the compression properties of stretchable knitted and bi-stretch woven fabrics for compression garments. For this purpose four woven structures and four knitted structures were produced having the same areal density and their compression, comfort and mechanical properties were compared before and after 5, 10 and 15 washes. Four knitted structures used were single jersey, single locaste, plain pique and the honeycomb, whereas four woven structures produced were 1/1 plain, 2/1 twill, 3/1 twill and 4/1 twill. The compression properties of the produced samples were tested by using kikuhime pressure sensor and it was found that bi-stretch woven fabrics possessed better compression properties before and after washes and retain their durability after repeated use, whereas knitted stretchable fabrics lost their compression ability after repeated use and the required sub garment pressure of the knitted structures after 15 washes was almost half to that of woven bi-stretch fabrics.

Keywords: compression garments, knitted structures, medical textiles, woven bi-stretch

Procedia PDF Downloads 411