Bridges Structural Health Monitoring and Deterioration Detection Synthesis of Knowledge and Technology

INE/AUTC 10.0

Fabricate

Bringing together pioneers in design and making within architecture, construction, engineering, manufacturing, materials technology and computation, Fabricate is a triennial international conference, now in its third year (ICD, University of Stuttgart, April 2017). Each year it produces a supporting publication, to date the only one of its kind specialising in Digital Fabrication. The 2017 edition features 32 illustrated articles on built projects and works in progress from academia and practice, including contributions from leading practices such as Foster + Partners, Zaha Hadid Architects, Arup, and Ron Arad, and from world-renowned institutions including ICD Stuttgart, Harvard, Yale, MIT, Princeton University, The Bartlett School of Architecture (UCL) and the Architectural Association

Numerical modelling of additive manufacturing process for stainless steel tension testing samples

Nowadays additive manufacturing (AM) technologies including 3D printing grow rapidly and they are expected to replace conventional subtractive manufacturing technologies to some extents. During a selective laser melting (SLM) process as one of popular AM technologies for metals, large amount of heats is required to melt metal powders, and this leads to distortions and/or shrinkages of additively manufactured parts. It is useful to predict the 3D printed parts to control unwanted distortions and shrinkages before their 3D printing. This study develops a two-phase numerical modelling and simulation process of AM process for 17-4PH stainless steel and it considers the importance of post-processing and the need for calibration to achieve a high-quality printing at the end. By using this proposed AM modelling and simulation process, optimal process parameters, material properties, and topology can be obtained to ensure a part 3D printed successfully

Constitutive model for fibre-reinforced composite materials exposed to high temperature

A la pàgina XIX del Sumari manquen: la pàgina 333: "Original publications" i les pàgines 335 a 361 "Bibliography"The high strength-weight ratio of composite materials have made them one of the best materials for the design of light-weight structures. However, its special complexity has made them not suitable for the design of structures with a relative complexity or with numerous structural component and pieces. Hence, the importance in the development of adequate constitutive models which allow simulating the micro-macro scale interaction of composites, and to address the intrinsic and natural flexibility of composites that is not as relevant in traditional materials. Meanwhile, the mechanical development of these materials is a mature research branch with more than four groundbreaking decades of life, this is not certainly met at the thermo-mechanical level which is still in an early stage and, consequently, limiting the extensive use of composites in real world and complex structures, particularly structures in which a strong and detailed fulfilment of fire criteria is necessary. E.g., this is the very situation in the large-length ship design sector, where the share in the market for ships built using composite material, tends to be very reduced and closely accompanied by tools which serve to perform structural health monitoring, in order to palliate, the amount of high uncertainty of the present thermo-mechanical response, found in the design of these structures. The present thesis focuses on the development, formulation-wise and computational implementation, of a numerical model in order to predict the non-linear constitutive behaviour of fibre-reinforced plastic (FRP) composites exposed to thermal degradation due to high temperatures. This very model is cemented in the groundbreaking development of constitutive mechanical formulations specially tailored for composites also known as rule of mixtures -- in this present context, the formulation is the so-called serial-parallel rule of mixtures -- which establish a set of closure equations to obtain the suitable micro-macro scale interaction of the composite structure and, at the same time, to take into account the characterisation of the internal and state variables of the constituent phases. Apart, the ultimate objective of this thesis, in this special context -- where a structure is under thermal loads or, what is the same, exposed to fire -- it is mandatory to develop a consistent formulation and tool to perform what is referred to as a fire collapse assessment analysis. The utilisation of a more sophisticated thermal degradation or pyrolysis formulation, based on the present existing formulations, will be employed in order to obtain the internal and state variables of the thermal degradation process. Thus, the outcome of this analysis will serve as means to obtain the unknown thermal state of the structure and complete the thermo-mechanical analysis. The formulation of the thermo-mechanical problem is adapted to be used in laminated non-linear constitutive shells. The use of shells is a necessity for the right optimisation of the computational cost of analysing structures with a high number of structural reinforcements or divisions, such as the ones that appear regularly during the ship design process of large ship structures.Per als materials compostos, la seva relació esforç-pes elevada ha fet d'ells un dels millors materials per al disseny d'estructures lleugeres. No obstant això, la seva especial complexitat, fa d'ells un difícil treball quan es tracta del disseny d'estructures amb una certa complexitat, o, en l'existència de nombroses divisions estructurals i peces. En conseqüència, el desenvolupament de models constitutius adients és de vital importància, en especial aquells que permeten la simulació de la interacció per la micro-macro escala dels compostos, i que resolguin la flexibilitat natural i intrínseca d'aquests materials avançats, qüestió que no és tan rellevant per al disseny de materials tradicionals. Mentrestant, el desenvolupament de teories mecàniques per aquests materials es troba ja a la seva maduració, amb més de quatre dècades de descobriments en aquesta branca. D'altra banda, en qüestions que involucren l'anàlisi termo-mecànica, el paradigma es considera relativament verd, el qual limita l'aplicació extensiva dels compostos en aplicacions pràctiques i d'estructures complexes, de fet, és particularment limitant en el disseny d'estructures que requereixen del compliment d'exigents i detallats criteris relatius al foc. E.g., això mateix succeeix en el disseny d'embarcacions de grans eslores, on la quota de mercat dels vaixells construïts mitjançant materials compostos sol ser reduïda, i estretament acompanyada per eines de monitoratge de la integritat estructural, per així poder pal·liar la gran incertesa vinculada a la resposta termo-mecànica, fruit de les capacitats del disseny comercial actual. L'actual tesi se centra en el desenvolupament, de manera teòrica, i amb corresponent implementació computacional, d'un model numèric capaç de predir el comportament no-linear constitutiu de compostos plàstics amb fibra embedida (FRP) quan aquests són exposats a altes temperatures i en conseqüència a la degradació tèrmica. Aquest mateix model està inspirat en els desenvolupaments, pioners i excepcionals, de models constitutius mecànics, els quals estan pensats per a compostos. Aquestes teories formen part de la família de les regles de barreges, en particular, la formulació escollida és la famosa regla de barreges sèrie-paral·lel, la qual estableix un conjunt d'equacions de tancament per així obtenir l'adequada interacció del material compost a la micro-macro escala. Aquesta formulació, a la mateixa vegada, té en compte la caracterització i evolució de tant variables internes com d'estat, per a les constitutives, en aquest context es tractaria de la fibra i la matriu. Per una altra banda, l'objectiu últim d'aquesta tesi, dins d'aquest context particular, on una estructura és sotmesa a càrregues tèrmiques, o en altres paraules, s'exposa al foc, és de forçosa necessitat el desenvolupament d'una formulació consistent i una eina capaç de verificar el que es podria batejar com una anàlisi de col·lapse al foc. L'ús d'una formulació més sofisticada per la degradació tèrmica o piròlisi, basada en formulació existent, serà empleat per així aconseguir les variables internes i d'estat dels processos de degradació tèrmica. En conseqüència, els resultats d'aquesta anàlisi tèrmica serveixen per a obtenir el desconegut estat tèrmic de l'estructura, la distribució de temperatura a través de l'espessor del laminat, i complementar l'anàlisi del model termo-mecànic. La formulació del problema termo-mecànic és adaptada per ser usada en làmines no lineals de materials compostos. Fer servir làmines és una necessitat per a la correcta optimització del cost computacional derivat de l'anàlisi d'estructures amb un alt nombre de reforços o divisions, anàlisis que són freqüentment trobats dins del procés del disseny d'embarcacions de grans eslores.Para los materiales compuestos, su relación esfuerzo-peso elevada ha hecho de ellos uno de los mejores materiales para el diseño de estructuras ligeras. No obstante, su especial complejidad, hace de ellos un arduo trabajo cuando se trata del diseño de estructuras con una cierta complejidad, o, en la existencia de numerosas divisiones estructurales o piezas. Consecuentemente, el desarrollo de modelos constitutivos adecuados es de importancia, en especial aquellos que permiten la simulación de la interacción para la micro-macro escala de los compuestos, y que resuelven la flexibilidad natural e intrínseca de estos materiales avanzados, cuestión que no es tan relevante para el diseño de materiales tradicionales. Mientras tanto, el desarrollo de teorías mecánicas para estos materiales se encuentra en su madurez, con más de cuatro décadas de hallazgos en esta rama. En contraposición, en cuestiones que atañen el análisis termo-mecánico, el paradigma se encuentra relativamente verde, lo cual limita la aplicación extensiva de los compuestos en aplicaciones prácticas y estructuras complejas, de hecho, es particularmente limitante en el diseño de estructuras que requieren del cumplimiento de exigentes y detallados criterios relativos al fuego. E.g., esto mismo sucede en el diseño de embarcaciones de grandes esloras, donde la cuota de mercado de los buques construidos mediante materiales compuestos suele ser reducida, y estrechamente acompañada por herramientas de monitorización de la integridad estructural, para así poder paliar la gran incertidumbre vinculada a la respuesta termo-mecánica, fruto de las capacidades del diseño comercial actual. La actual tesis se centra en el desarrollo, de manera teórica, y con su correspondiente implementación computacional, de un modelo numérico capaz de predecir el comportamiento no-lineal constitutivo de compuestos plásticos con fibra embebida (FRP) cuando estos son expuestos a altas temperaturas y en consecuencia a la degradación térmica. Este mismo modelo está inspirado en los desarrollos, pioneros y excepcionales, de modelos constitutivos mecánicos, las cuales están pensadas para compuestos. Estas teorías forman parte de la familia de las reglas de mezclas, en particular, la formulación escogida es la renombrada regla de mezclas serie-paralelo, la cual establece un conjunto de ecuaciones de cierre para así obtener la adecuada interacción del material compuesto en la micro-macro escala. Esta formulación, a su misma vez, tiene en cuenta la caracterización y evolución de tanto variables internas como de estado, para las fases constituyentes, en este contexto se trataría de la fibra y la matriz. Por otra banda, el objetivo último de esta tesis, dentro de este contexto particular, donde una estructura se somete a cargas térmicas, o, en otras palabras, se expone al fuego, es de forzosa necesidad el desarrollo de una formulación consistente y una herramienta capaz de verificar lo que se puede acuñar como un análisis de colapso al fuego. El uso de una formulación más sofisticada para la degradación térmica o pirolisis, basada en formulación existente, será empleado para así obtener las variables internas y de estado de los procesos de degradación térmica. En consecuencia, los resultados de este análisis térmico sirven para obtener el desconocido estado térmico de la estructura, la distribución de temperatura a través del espesor del laminado, y complementar el análisis termo-mecánico. La formulación del problema termo mecánico es adaptada para ser usada en láminas no lineales de materiales compuestos. Usar láminas es una necesidad para la correcta optimización del coste computacional derivado del análisis de estructuras con un alto número de refuerzos o divisiones, análisis que son frecuentemente encontrados en el proceso de diseño de embarcaciones de grandes esloras.Postprint (published version

Proceedings of IWAMISSE 2018 the International Workshop on Advanced Materials and Innovative Systems in Structural Engineering: Seismic Practices

The International Workshop on Advanced Materials and Innovative Systems in Structural Engineering: Seismic Practices, IWAMISSE 2018, is co-organised by The International Federation for Structural Concrete Turkey Branch, fib-Turkey, and Istanbul Technical University, ITU, on November 16, 2018 at ITU. The International Federation for Structural Concrete, fib, is a not-for-profit association formed by 45 national member groups and approximately 1000 corporate and individual members. The fib’s mission is to develop at an international level the study of scientific and practical matters capable of advancing the technical, economic, aesthetic and environmental performance of concrete construction. Istanbul Technical University (ITU) was established in 1773 and is a state university which defined and continues to update methods of engineering and architecture in Turkey. It provides its students with innovative educational facilities while retaining traditional values, as well as using its strong international contacts to mould young, talented individuals who can compete not only within their country borders but also in the global arena. With its educational facilities, social life and strong institutional contacts, ITU has always been preferred by Turkey’s most distinguished students since its foundation and has achieved justified respect. The workshop covers the topics of advanced materials and innovative systems in structural engineering with a focus on seismic practices as well as other issues related with steel fiber reinforced concrete, anchors/fasteners, precast structures, and recent advances on different types of structural systems such as reinforced concrete, steel, and reinforced masonry structures. This proceeding book contain sixteen papers from ten countries worldwide. We have no doubt that the up-to-date subjects covered during the workshop will be extremely beneficial for the workshop participants both from academia and industry. We would like to thank all authors for their contributions to the workshop as well as the members of the International Scientific Committee for their rigorous work for reviewing the papers. We also gratefully acknowledge the support of the sponsoring companies and we express our sincere thanks to organization committee for their tireless efforts in the overall organization of the workshop. Many thanks go as well to undergraduate and graduate students from ITU for their assistance during all stages of the workshop

무보강 조적식 역사 구조물의 보존과 복구

학위논문(박사) -- 서울대학교대학원 : 공과대학 건축학과, 2021.8. 강현구.역사적 구조물은 인류의 문화적, 건축적, 역사적 가치를 지니며, 동시에 이러한 가치를 미래 세대에게 전달하는 데 있어 중요한 역할을 한다. 그러나, 많은 문화 유산들은 오랜 세월 지진이나 기타 자연재해로 심각한 피해를 입어왔다. 구조적인 측면에서 볼 때, 높은 질량, 낮은 인장강도, 낮은 전단강도 및 낮은 연성 등이 불리하게 작용하였으며, 조적조 구조물의 경우 재료의 특성, 형상, 구성, 요소 배치, 연결부, 기초의 강도 등 여러 변수가 해당 구조물의 내진거동에 영향을 끼쳤다. 이는 구조물의 부분 및 전체 붕괴로 이어질 수 있기에 역사적인 조적조 구조물의 보존과 보강은 계속적으로 연구가 필요한 주제이다. 본 논문에서는, 가장 중요한 구조적 요소인 비보강 조적조 벽체의 건축적, 구조적 특성을 분석하였고, 지진하중에 의해 야기되는 전형적인 손상에 대해 서술하였다. 그 후, 분석적 연구에 적합한 방법을 선택하기 위해 몇 가지 보강 방법에 대한 장단점을 조사하였다. 본 연구에서는 여러 유형의 비보강 조적조 벽체 중 건식 석조 벽체에 특히 집중하여 분석이 진행되었다. 유한요소해석을 통해 단조 및 반복 가력에서의 벽체 거동이 평가되었고, 수치해석 결과를 검증하기 위해 기존 연구자들의 실험결과가 사용되었다. 또한, 요소와 벽체의 배열 및 규모에 따라 매개변수적 연구가 수행되었다. 최종적으로 모델의 수치해석 결과와 파괴 양상을 고려하여 해당 구조물에 적합한 보강 방법이 선정되었다. 이 때, 기존의 역사적 구조물의 보강에 있어 가장 효율적이고 실용적인 방법 중 하나로 평가 받고 있는 철근 삽입 공법이 심층 분석되었다. 가장 효율적인 재료와 철근 배치를 탐구하기 위해 매개변수적 연구가 추가적으로 수행되었다. 본 논문의 연구를 통하여 궁극적으로 비보강 조적조 벽체의 내진거동과 적절한 보강 방법, 그리고 이를 어떻게 향상시킬 수 있는 지에 대한 해법을 도출할 수 있었다.Historical structures constitute the most significant part of the cultural, architectural, and historical values of past peoples, which play an important role in transmitting these values to future generations. Many of these cultural heritage buildings have been severely damaged by past earthquakes or other natural disasters. In terms of structural property, the main defects are related to high specific mass, low tensile strength, low to moderate shear strength, and low ductility. The seismic behavior of masonry buildings highly depends on the material properties, geometry, configuration, arrangements of units, connections, foundation strength, etc. These features may cause them to be vulnerable to a sudden movement which can be terminated by the partial or entire collapse of the structure. Therefore, preservation and protection of this type of structure is an interesting topic and of great concern for the engineering community. This dissertation deals with a detailed architectural and structural characterization of different types of unreinforced masonry (URM) walls as the most important structural element and explains their typical damage caused by seismic loads. Then, several retrofitting methods including their advantages and shortcomings were investigated to choose an appropriate method for analytical studies. Among all types of URM walls, the dry-stack stone masonry wall was selected and its behavior under monotonic and cyclic loads was evaluated using finite element method (FEM). To validate the results of numerical analysis, all FEM models were calibrated with a set of experimental investigations that have been conducted by other researchers. Then, some parametric studies were conducted for different arrangements and scales of units and walls. Regarding the results of numerical analysis and failure modes observed in the models, an appropriate retrofitting method was determined. Given the existing limitations on retrofitting historical structures, inserting rebars into the wall was considered as one of the most efficient and practical retrofit techniques. Finally, a parametric study has been done for materials and arrangements of inserted rebars with a hope to achieve the most efficient case. The results obtained by this study led to a deeper understanding of the seismic behavior of URM walls and how it can be enhanced by a proper retrofit technique.Chapter 1. Introduction 1 1.1 History and Motivation 2 1.2 Scope and Methodology 10 1.3 Organization 13 Chapter 2. Technical Investigation of HURM Structures 15 2.1 General Description 16 2.2 Architectural Characterization 17 2.2.1 Material classification 18 2.2.2 Geometry 24 2.3 Structural Characterization 26 2.3.1 Structural components 27 2.3.2 Masonry components 34 2.4 Wall Behavior 37 2.4.1 Wall behavior under compressive load 39 2.4.2 Wall behavior under tensile load 41 2.4.3 Wall behavior under shear load 43 2.5 Summary 44 Chapter 3. Typical Seismic Damage in HURM Buildings 45 3.1 Typical Damage of HURM Structures 46 3.2 Damage in Non-Structural Elements 48 3.3 Damage in Structural Elements 49 3.3.1 Connection failure 50 3.3.2 Wall failure 53 3.3.3 Diaphragm failure 61 3.3.4 Foundation failure 61 3.4 Impact of Erosion on the Performance of HURM Buildings 63 3.4.1 Wind 65 3.4.2 Temperature 66 3.4.3 Rain and humidity 66 3.4.4 Biological damage 67 3.4.5 Human intervention 68 3.5 Summary 68 Chapter 4. Technical Issues and Methods of Preservation for HURM Structures 69 4.1 Preservation Techniques for HURM 70 4.2 Improving Structural Integrity 73 4.2.1 Confinements 73 4.2.2 Transversal anchorage 78 4.2.3 Strengthening of junction 78 4.2.4 Textile reinforced mortar and steel reinforced grout 79 4.2.5 Mortar joint treatment 81 4.2.6 Strengthening of roof diaphragm 86 4.3 Reducing Seismic Demands 87 4.3.1 Base isolation 87 4.3.2 Seismic damper 89 4.4 Upgrading Structural Components 89 4.4.1 Reinforced concrete wall 90 4.4.2 Moment and braced frames 91 4.4.3 Surface treatment 92 4.4.4 External reinforcements 96 4.4.5 Post-tensioning 106 4.4.6 Mesh reinforcement 109 4.4.7 Reticulatus system 113 4.5 Technical Comparison 116 4.6 Summary 120 Chapter 5. Experimental and Numerical Methods for HURM Structures 121 5.1 General Description 122 5.2 Experimental Method 123 5.2.1 Material test 124 5.2.2 Structural test 133 5.3 Numerical Analysis Methods 137 5.3.1 Concept of macro and micro approaches 140 5.3.2 Kinematic method 146 5.3.3 Finite element method 149 5.3.4 Discrete element method 153 5.4 Analysis Types 155 5.4.1 Linear static analysis (LSA) 159 5.4.2 Linear dynamic analysis (LDA) 161 5.4.3 Nonlinear static analysis (NSA) 164 5.4.4 Nonlinear dynamic analysis (NDA) 167 5.5 Material and Joint Behavior 168 5.6 Summary 174 Chapter 6. Numerical Modeling of Stone Wall 175 6.1 General Descriptions 176 6.2 Experimental Research Program 178 6.3 ABAQUS Software 187 6.4 Numerical Model 191 6.5 Calibration and Validation of Numerical Models 198 6.6 Sensitivity Analysis 207 6.6.1 Penalty stiffness sensitivity analysis 207 6.6.2 Mesh size sensitivity analysis 210 6.6.3 Friction coefficient sensitivity analysis 214 6.6.4 Comparison of 2D and 3D analyses 218 6.6.5 Comparison of pushover and cyclic analysis 224 6.7 Parametric Study 232 6.8 Summary 245 Chapter 7. FEM Analysis of Stone Masonry Walls Retrofitted by Rebars 247 7.1 Proposed Retrofit Technique 248 7.2 Material Properties 251 7.3 Numerical Modeling Assumptions 254 7.4 Retrofitting Program 256 7.4.1 Horizontal rebar models 256 7.4.2 Vertical rebar models 262 7.4.3 Diagonal rebar models 282 7.5 Comparative Studies 302 7.6 Cyclic Analysis 306 7.7 Summary 318 Chapter 8. Summary and Conclusion 319 8.1 Summary 320 8.2 Conclusion 322 8.3 Future Work 328 References 329 Acknowledgment 359 Abstract in Korean 360박

Active thermography for the investigation of corrosion in steel surfaces

The present work aims at developing an experimental methodology for the analysis of corrosion phenomena of steel surfaces by means of Active Thermography (AT), in reflexion configuration (RC). The peculiarity of this AT approach consists in exciting by means of a laser source the sound surface of the specimens and acquiring the thermal signal on the same surface, instead of the corroded one: the thermal signal is then composed by the reflection of the thermal wave reflected by the corroded surface. This procedure aims at investigating internal corroded surfaces like in vessels, piping, carters etc. Thermal tests were performed in Step Heating and Lock-In conditions, by varying excitation parameters (power, time, number of pulse, ….) to improve the experimental set up. Surface thermal profiles were acquired by an IR thermocamera and means of salt spray testing; at set time intervals the specimens were investigated by means of AT. Each duration corresponded to a surface damage entity and to a variation in the thermal response. Thermal responses of corroded specimens were related to the corresponding corrosion level, referring to a reference specimen without corrosion. The entity of corrosion was also verified by a metallographic optical microscope to measure the thickness variation of the specimens

Physically based constitutive models for crash of composites

The transportation industry and passenger cars in particular are strong emitters of gases that contribute to the climate crisis. For this reason, the automotive industry investigates opportunities to reduce emissions, such as reducing the weight of the car. Composite materials, due to their high strength, stiffness and energy absorption to weight ratio, are a suitable material choice to reduce weight. The challenge here is that composites do not satisfy the fast development times and low costs required by the car industry. An efficient design phase, using more simulation and less physical testing, allows for time and cost-savings. However, there is a lack of efficient computational models to help the design with composite materials, which is fundamental for a widespread usage of composites in the automotive industry. This thesis presents the development, improvement and validation of constitutive models for composites in crash, focusing on compressive damage modes, matrix compression and fibre compression. The material being modelled is a carbon fibre/epoxy uni-weave Non-Crimp Fabric (NCF) composite. The properties of the composite constituents are homogenized to the ply level for a more efficient modelling.The matrix behaviour is modelled by combining damage and friction on the microcrack surfaces. The transverse mechanisms are modelled efficiently using a criterion for final failure, interaction of damage modes and a continuous response between compression and tension. The model is validated against 45- and 90-degree specimens. The fibre compression mode is fibre kinking growth, a very complex mechanism, responsible for high energy absorption. A homogenized 3D model based on Fibre Kinking Theory (FKT) is developed. It includes initial fibre misalignments and further rotations are governed by equilibrium with shear nonlinearity. The model is implemented in a commercial Finite Element (FE) software together with a mesh objective methodology. Furthermore, another formulation with similar physical principles but more suitable, efficient and robust for crash simulations is developed, implemented in an FE software and validated against experiments. The results show good qualitative and quantitative agreement. The proposed models allow for a reduction of physical testing required to develop crashworthy structures

Hull construction with composite materials for ships over 100 m in length

Thesis (Nav.E. and S.M. in Ocean Systems Management)--Massachusetts Institute of Technology, Dept. of Ocean Engineering, 2002.Includes bibliographical references (leaves 124-132).The operational envelope of the maritime industry requires high performance marine vessels, which demand increased structural integrity and durability, coupled with significant weight reduction and minimization of cost. The design and fabrication of a "large vessel" by use of composite materials is within the current technology. However, a number of major technical and economic aspects are questionable. This study will examine the structural design for vessels longer than 100 m. It will also identify the major advantages and disadvantages of this composite structure compared with one made of steel, focusing on the technical and economic aspects. Material selection, fabrication methods and design concepts for composite structures, such as elimination of frames, will be explored and comparisons will be developed. The potential to significantly reduce or even eliminate the risk areas will be evaluated. Four different structural designs of a hull from composite materials are examined for a midship section of an existing naval ship (DDG51 type) and they are compared to the one built from steel. In order to select the best option of these structural designs, three variants are analyzed: structural configuration of composites, material option and fabrication process. Additionally, the effect of several critical areas, such as safety factors selection, present and future structural limitations, required fabrication experience, durability, complexity, infrastructure issues, and a cost and market analysis of using fiber reinforced plastic (FRP) in ship design and construction are included in this study. The proposed hull design combined with the optimum materials and fabrication method shows that a large ship is both technically and economically feasible.by Konstantinos Galanis.Nav.E.and S.M.in Ocean Systems Managemen