Abstract This 3D coupled hygro-elastic model proposes the three-dimensional (3D) equilibrium equations associated with the 3D Fick diffusion equation for spherical shells. The primary unknowns of the problem are the displacements and the moisture content. This coupled 3D exact shell model allows to understand the effects of the moisture field in relation with the elastic field on stresses and deformations in different plates and shells. This model is specifically developed for configurations including functionally graded material (FGM) layers. Four different geometries are analyzed using an orthogonal mixed curvilinear reference system. The main advantage of this reference system for spherical shells is the degeneration of the equations to those for simpler geometries. The solving method is the exponential matrix method in the thickness direction. The closed-form solution is possible because of simply supported sides and harmonic forms for displacements and moisture content. The moisture content amplitudes are directly applied at the top and bottom outer faces through steady-state hypotheses. The final system is based on a set of coupled homogeneous second-order differential equations. The moisture field effects are evaluated for the static analysis in terms of displacement, strain, and stress components. After preliminary validations, used to better understand how to properly define the calculation of the curvature-related terms and FGM properties, four new benchmarks are proposed for several thickness ratios, geometrical data, FGM configurations, and moisture values imposed at the external surfaces. From the results, it is clear the accordance between the uncoupled hygro-elastic model and this new coupled hygro-elastic model when the 3D Fick diffusion law is employed. Both effects connected with the thickness layer and the embedded material are included in the 3D hygro-elastic analyses proposed. The 3D coupled hygro-elastic model is simpler than the uncoupled one because the 3D Fick diffusion law does not have to be separately solved.
{"title":"A coupled hygro-elastic 3D model for steady-state analysis of functionally graded plates and shells","authors":"Salvatore Brischetto, Domenico Cesare","doi":"10.1515/cls-2022-0216","DOIUrl":"https://doi.org/10.1515/cls-2022-0216","url":null,"abstract":"Abstract This 3D coupled hygro-elastic model proposes the three-dimensional (3D) equilibrium equations associated with the 3D Fick diffusion equation for spherical shells. The primary unknowns of the problem are the displacements and the moisture content. This coupled 3D exact shell model allows to understand the effects of the moisture field in relation with the elastic field on stresses and deformations in different plates and shells. This model is specifically developed for configurations including functionally graded material (FGM) layers. Four different geometries are analyzed using an orthogonal mixed curvilinear reference system. The main advantage of this reference system for spherical shells is the degeneration of the equations to those for simpler geometries. The solving method is the exponential matrix method in the thickness direction. The closed-form solution is possible because of simply supported sides and harmonic forms for displacements and moisture content. The moisture content amplitudes are directly applied at the top and bottom outer faces through steady-state hypotheses. The final system is based on a set of coupled homogeneous second-order differential equations. The moisture field effects are evaluated for the static analysis in terms of displacement, strain, and stress components. After preliminary validations, used to better understand how to properly define the calculation of the curvature-related terms and FGM properties, four new benchmarks are proposed for several thickness ratios, geometrical data, FGM configurations, and moisture values imposed at the external surfaces. From the results, it is clear the accordance between the uncoupled hygro-elastic model and this new coupled hygro-elastic model when the 3D Fick diffusion law is employed. Both effects connected with the thickness layer and the embedded material are included in the 3D hygro-elastic analyses proposed. The 3D coupled hygro-elastic model is simpler than the uncoupled one because the 3D Fick diffusion law does not have to be separately solved.","PeriodicalId":44435,"journal":{"name":"Curved and Layered Structures","volume":"30 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135911264","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Natiq Abbas Fadhil, K. A. Hammoodi, L. Jassim, Hasan A. Al-Asadi, L. Habeeb
Abstract With the development of simulation programs, it is necessary to simulate the problems that occur in the human body that are related to mechanical engineering. Whereas blood is a liquid with mechanical properties, the artery is a substance that also contains mechanical properties. Smoking increases blood viscosity, and this viscosity affects the velocity and blood pressure as well as the artery itself. In this research article, the effect of blood viscosity on the aorta will be studied because it is one of the main arteries of the heart and obtains blood flow in the artery. The blood’s kinetic equations were solved using the COMSOL program’s laminar processor, and fluid–structure interaction was utilized to connect the mechanics of motion with the stresses that affect the artery. In addition, the effect of viscosity on the deformation of the artery and its movement was studied, and the result showed that most of the blood does not reach the branches of the artery, where the speed of blood flow was 0.18 m/s at the value of the viscosity of 0.1 Pa s. The increase in viscoelasticity leads to an increase in pressure at the beginning of the carotid artery, which hinders the flow of blood. The velocity of blood flow decreases with the increase in viscosity, and this reduces pressure on the artery walls, as the stress on 0.1 Pa s was equal to 16,705 Pa s (m.124). An artery’s deformation is directly related to the stresses on it, and when the deformation goes down, the artery’s size goes down.
{"title":"Multiphysics analysis for fluid–structure interaction of blood biological flow inside three-dimensional artery","authors":"Natiq Abbas Fadhil, K. A. Hammoodi, L. Jassim, Hasan A. Al-Asadi, L. Habeeb","doi":"10.1515/cls-2022-0187","DOIUrl":"https://doi.org/10.1515/cls-2022-0187","url":null,"abstract":"Abstract With the development of simulation programs, it is necessary to simulate the problems that occur in the human body that are related to mechanical engineering. Whereas blood is a liquid with mechanical properties, the artery is a substance that also contains mechanical properties. Smoking increases blood viscosity, and this viscosity affects the velocity and blood pressure as well as the artery itself. In this research article, the effect of blood viscosity on the aorta will be studied because it is one of the main arteries of the heart and obtains blood flow in the artery. The blood’s kinetic equations were solved using the COMSOL program’s laminar processor, and fluid–structure interaction was utilized to connect the mechanics of motion with the stresses that affect the artery. In addition, the effect of viscosity on the deformation of the artery and its movement was studied, and the result showed that most of the blood does not reach the branches of the artery, where the speed of blood flow was 0.18 m/s at the value of the viscosity of 0.1 Pa s. The increase in viscoelasticity leads to an increase in pressure at the beginning of the carotid artery, which hinders the flow of blood. The velocity of blood flow decreases with the increase in viscosity, and this reduces pressure on the artery walls, as the stress on 0.1 Pa s was equal to 16,705 Pa s (m.124). An artery’s deformation is directly related to the stresses on it, and when the deformation goes down, the artery’s size goes down.","PeriodicalId":44435,"journal":{"name":"Curved and Layered Structures","volume":" ","pages":""},"PeriodicalIF":1.5,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48171373","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Ben Ganendra, A. Prabowo, T. Muttaqie, R. Adiputra, Ridwan Ridwan, Aprianur Fajri, Quang Thang Do, H. Carvalho, S. Baek
Abstract Cylindrical shell structures are ubiquitous and essential supporting structures in various engineering applications. The aim of this research work is to provide a comprehensive overview of the behavior of cylindrical shell structures under different loading conditions, including external pressure, axial compression, and bending moment. The study found that the behavior of cylindrical shells was affected by their geometry, including diameter, length, thickness, and imperfections. These factors should be carefully considered in the design and analysis of cylindrical shells. Additionally, stiffeners and sandwich structures can be applied to improve the structural performance of cylindrical shells under different loading conditions. The work also highlighted the latest research trends in the field, such as the use of advanced materials, and numerical simulations to improve the understanding and design of cylindrical shell structures. Overall, this study has provided a valuable resource for engineers and researchers working on cylindrical shell structures, helping them to design and analyze the cylindrical shell structures more efficiently and effectively.
{"title":"Thin-walled cylindrical shells in engineering designs and critical infrastructures: A systematic review based on the loading response","authors":"Ben Ganendra, A. Prabowo, T. Muttaqie, R. Adiputra, Ridwan Ridwan, Aprianur Fajri, Quang Thang Do, H. Carvalho, S. Baek","doi":"10.1515/cls-2022-0202","DOIUrl":"https://doi.org/10.1515/cls-2022-0202","url":null,"abstract":"Abstract Cylindrical shell structures are ubiquitous and essential supporting structures in various engineering applications. The aim of this research work is to provide a comprehensive overview of the behavior of cylindrical shell structures under different loading conditions, including external pressure, axial compression, and bending moment. The study found that the behavior of cylindrical shells was affected by their geometry, including diameter, length, thickness, and imperfections. These factors should be carefully considered in the design and analysis of cylindrical shells. Additionally, stiffeners and sandwich structures can be applied to improve the structural performance of cylindrical shells under different loading conditions. The work also highlighted the latest research trends in the field, such as the use of advanced materials, and numerical simulations to improve the understanding and design of cylindrical shell structures. Overall, this study has provided a valuable resource for engineers and researchers working on cylindrical shell structures, helping them to design and analyze the cylindrical shell structures more efficiently and effectively.","PeriodicalId":44435,"journal":{"name":"Curved and Layered Structures","volume":" ","pages":""},"PeriodicalIF":1.5,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41823663","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Muryadin, T. Muttaqie, C. Sasmito, F. Noor, Andi C. P. T. Nugroho, Dany Hendrik Priatno, Buddin Al Hakim, Abid Paripurna Fuadi, Muh Hisyam Khoirudin, Teguh Wibowo, Arfis Maydino F. Putra
Abstract The inelastic deformation of a 30 m high-speed craft (HSC) subjected to slamming pressure is the main topic of this research. In this work, the commercial software package ABAQUS FEA is used to predict the structural behavior, especially in the hull area under the chine. Dynamic explicit solver simulations are done to predict plastic deformation. Before the principal analysis of the actual size of the ship hull structure model, the numerical studies were validated against relevant experimental data from the previous open literature. A reassessment of the design guidelines was also done to forecast the slamming load on the HSC structure. Then, with the slamming load pressure increased to the design limit, a parametric analysis was also conducted with two different idealizations of the pressure type: rectangular and triangular. Finally, this study identifies the variables that must be considered when calculating the degree of structural deformation brought on by slamming loads.
{"title":"Dynamic response of high-speed craft bottom panels subjected to slamming loadings","authors":"Muryadin, T. Muttaqie, C. Sasmito, F. Noor, Andi C. P. T. Nugroho, Dany Hendrik Priatno, Buddin Al Hakim, Abid Paripurna Fuadi, Muh Hisyam Khoirudin, Teguh Wibowo, Arfis Maydino F. Putra","doi":"10.1515/cls-2022-0190","DOIUrl":"https://doi.org/10.1515/cls-2022-0190","url":null,"abstract":"Abstract The inelastic deformation of a 30 m high-speed craft (HSC) subjected to slamming pressure is the main topic of this research. In this work, the commercial software package ABAQUS FEA is used to predict the structural behavior, especially in the hull area under the chine. Dynamic explicit solver simulations are done to predict plastic deformation. Before the principal analysis of the actual size of the ship hull structure model, the numerical studies were validated against relevant experimental data from the previous open literature. A reassessment of the design guidelines was also done to forecast the slamming load on the HSC structure. Then, with the slamming load pressure increased to the design limit, a parametric analysis was also conducted with two different idealizations of the pressure type: rectangular and triangular. Finally, this study identifies the variables that must be considered when calculating the degree of structural deformation brought on by slamming loads.","PeriodicalId":44435,"journal":{"name":"Curved and Layered Structures","volume":" ","pages":""},"PeriodicalIF":1.5,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49472181","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Ma’ruf Yanuar Effendi, U. Ubaidillah, E. P. Budiana, B. W. Lenggana
Abstract An electric motor mounting bracket is used in electric vehicles, especially hybrid ones using a parallel hybrid configuration. This study aims to analyze the strength and performance of the initial design and topology optimized design. This study uses the finite-element method (FEM) in the bracket design modeling by applying topology optimization. The topology optimization results show a mass reduction of 50% from the initial design mass. In the case of static loading, the results of optimized design 2 have a stress of 142.19 MPa and a safety factor of 3.09. While optimized design 1 has a stress of 313.8 MPa and a safety factor of 1.4. In terms of dynamic loading, the initial design, optimized design 1, and optimized design 2 have the first natural frequency, which is higher than the operating frequency of the electric motor, respectively, 100.49, 69.043, and 74.864 Hz. Optimized design 1 has the lowest natural frequency and the highest amplitude compared to the initial design, and optimized design 2 has lower damping characteristics. The study results conclude that optimized design 2 is superior in static and dynamic loading.
{"title":"Performance analysis on the structure of the bracket mounting for hybrid converter kit: Finite-element approach","authors":"Ma’ruf Yanuar Effendi, U. Ubaidillah, E. P. Budiana, B. W. Lenggana","doi":"10.1515/cls-2022-0206","DOIUrl":"https://doi.org/10.1515/cls-2022-0206","url":null,"abstract":"Abstract An electric motor mounting bracket is used in electric vehicles, especially hybrid ones using a parallel hybrid configuration. This study aims to analyze the strength and performance of the initial design and topology optimized design. This study uses the finite-element method (FEM) in the bracket design modeling by applying topology optimization. The topology optimization results show a mass reduction of 50% from the initial design mass. In the case of static loading, the results of optimized design 2 have a stress of 142.19 MPa and a safety factor of 3.09. While optimized design 1 has a stress of 313.8 MPa and a safety factor of 1.4. In terms of dynamic loading, the initial design, optimized design 1, and optimized design 2 have the first natural frequency, which is higher than the operating frequency of the electric motor, respectively, 100.49, 69.043, and 74.864 Hz. Optimized design 1 has the lowest natural frequency and the highest amplitude compared to the initial design, and optimized design 2 has lower damping characteristics. The study results conclude that optimized design 2 is superior in static and dynamic loading.","PeriodicalId":44435,"journal":{"name":"Curved and Layered Structures","volume":" ","pages":""},"PeriodicalIF":1.5,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48472969","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
R. Dimitri, M. Rinaldi, Francesco Tornabene, F. Micelli
Abstract In a context where daily and seasonal temperature changes or potential fire exposure can affect the mechanical response of structures strengthened with fiber-reinforced polymer (FRP) composites during their life cycle, the present work studies the bond behavior of FRP laminates glued to concrete substrates under a thermal variation. The problem is tackled computationally by means of a contact algorithm capable of handling both the normal and tangential cohesive responses, accounting for the effect of thermal variations on the interfacial strength and softening parameters, which defines the failure surface and post cracking response of the selected specimen. A parametric investigation is performed systematically to check for the effect of thermo-mechanical adhesive and geometrical properties on the debonding load of the FRP-to-concrete structural system. The computational results are successfully validated against some theoretical predictions from literature, which could serve as potential benchmarks for developing further thermo-mechanical adhesive models, even in a coupled sense, for other reinforcement-to-substrate systems, useful for design purposes in many engineering applications.
{"title":"Numerical study of the FRP-concrete bond behavior under thermal variations","authors":"R. Dimitri, M. Rinaldi, Francesco Tornabene, F. Micelli","doi":"10.1515/cls-2022-0193","DOIUrl":"https://doi.org/10.1515/cls-2022-0193","url":null,"abstract":"Abstract In a context where daily and seasonal temperature changes or potential fire exposure can affect the mechanical response of structures strengthened with fiber-reinforced polymer (FRP) composites during their life cycle, the present work studies the bond behavior of FRP laminates glued to concrete substrates under a thermal variation. The problem is tackled computationally by means of a contact algorithm capable of handling both the normal and tangential cohesive responses, accounting for the effect of thermal variations on the interfacial strength and softening parameters, which defines the failure surface and post cracking response of the selected specimen. A parametric investigation is performed systematically to check for the effect of thermo-mechanical adhesive and geometrical properties on the debonding load of the FRP-to-concrete structural system. The computational results are successfully validated against some theoretical predictions from literature, which could serve as potential benchmarks for developing further thermo-mechanical adhesive models, even in a coupled sense, for other reinforcement-to-substrate systems, useful for design purposes in many engineering applications.","PeriodicalId":44435,"journal":{"name":"Curved and Layered Structures","volume":" ","pages":""},"PeriodicalIF":1.5,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47789198","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Aditya Rio Prabowo, Ridwan Ridwan, Moritz Braun, Shi Song, Sören Ehlers, Nurman Firdaus, Ristiyanto Adiputra
Abstract This work made a comparison of the effects of selected element formulations (EFs) through nonlinear finite element analysis (NLFEA) and physical configurations in scenario design, particularly target locations. The combined results help in quantifying structural performance, focusing on crashworthiness criteria. The analysis involves nonlinear dynamic finite element methods, using an explicit approach applied to an idealized system. This system models ship-to-ship collisions, specifically the interaction between Ro and Ro and cargo reefer vessels, with one striking the other. Summarizing initial NLFEA results reveals that the chosen EF significantly influences the crashworthiness criteria. Notably, differences in formulations lead to different calculation times. The Belytschko–Tsay (BT) EF is the quickest, followed by the Belytschko–Leviathan (BL), with around a 36% difference. Conversely, formulations such as the Hughes–Liu involve much longer processing times, more than twice that of BT. To address the potential impact of shear locking and hourglassing on calculation accuracy during impact, the fully integrated (FI) version of the EF is used. It mitigates these undesired events. For formulations with the same approach, the FI BT formulation suppresses hourglassing effectively, unlike others that show orthogonal hourglassing increments. To ensure reliability, rules were set to assess hourglassing. The criterion is that the ratio of hourglass energy to internal energy should be ≤10%. All formulations meet this criterion and are suitable as geometric models in NLFEA. Regarding reliability and processing time, analyzing the computation time offers insights. Based on calculations, BL is the fastest, followed by Belytschko–Wong–Chiang, while the FI BT formulation takes more time for the same collision case.
{"title":"Comparative study of shell element formulations as NLFE parameters to forecast structural crashworthiness","authors":"Aditya Rio Prabowo, Ridwan Ridwan, Moritz Braun, Shi Song, Sören Ehlers, Nurman Firdaus, Ristiyanto Adiputra","doi":"10.1515/cls-2022-0217","DOIUrl":"https://doi.org/10.1515/cls-2022-0217","url":null,"abstract":"Abstract This work made a comparison of the effects of selected element formulations (EFs) through nonlinear finite element analysis (NLFEA) and physical configurations in scenario design, particularly target locations. The combined results help in quantifying structural performance, focusing on crashworthiness criteria. The analysis involves nonlinear dynamic finite element methods, using an explicit approach applied to an idealized system. This system models ship-to-ship collisions, specifically the interaction between Ro and Ro and cargo reefer vessels, with one striking the other. Summarizing initial NLFEA results reveals that the chosen EF significantly influences the crashworthiness criteria. Notably, differences in formulations lead to different calculation times. The Belytschko–Tsay (BT) EF is the quickest, followed by the Belytschko–Leviathan (BL), with around a 36% difference. Conversely, formulations such as the Hughes–Liu involve much longer processing times, more than twice that of BT. To address the potential impact of shear locking and hourglassing on calculation accuracy during impact, the fully integrated (FI) version of the EF is used. It mitigates these undesired events. For formulations with the same approach, the FI BT formulation suppresses hourglassing effectively, unlike others that show orthogonal hourglassing increments. To ensure reliability, rules were set to assess hourglassing. The criterion is that the ratio of hourglass energy to internal energy should be ≤10%. All formulations meet this criterion and are suitable as geometric models in NLFEA. Regarding reliability and processing time, analyzing the computation time offers insights. Based on calculations, BL is the fastest, followed by Belytschko–Wong–Chiang, while the FI BT formulation takes more time for the same collision case.","PeriodicalId":44435,"journal":{"name":"Curved and Layered Structures","volume":"47 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"136305879","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Abstract A reliability-based approach is presented to investigate the effects of structural and load uncertainties on the reliability estimation of ship hull girders. Structural uncertainties included randomness in material properties, geometric properties, initial geometric imperfections, and corrosion behavior. Load uncertainties included statistical uncertainties, model uncertainties, environmental uncertainties, and uncertainties related to nonlinearity. The hull girder ultimate strength was calculated using Smith’s method, and the probabilistic density function was evaluated by employing Monte Carlo simulations. In the load estimation, the still water bending moment and wave-induced bending moment were calculated using a simplified formula of the International Association of Classification Societies-Common Structural Rules code and then modified with load parameters. The reliability index was estimated using a first-order reliability method considering the operating time, the duration of the ship in the alternate hold loading condition, and the severity of the corrosion rate. As a result, sagging conditions dominated the collapse mode. The reliability indexes were obtained for the observed cases, and the viability of the ship was assessed accordingly.
{"title":"Reliability-based assessment of ship hull girder ultimate strength","authors":"R. Adiputra, T. Yoshikawa, Erwandi Erwandi","doi":"10.1515/cls-2022-0189","DOIUrl":"https://doi.org/10.1515/cls-2022-0189","url":null,"abstract":"Abstract A reliability-based approach is presented to investigate the effects of structural and load uncertainties on the reliability estimation of ship hull girders. Structural uncertainties included randomness in material properties, geometric properties, initial geometric imperfections, and corrosion behavior. Load uncertainties included statistical uncertainties, model uncertainties, environmental uncertainties, and uncertainties related to nonlinearity. The hull girder ultimate strength was calculated using Smith’s method, and the probabilistic density function was evaluated by employing Monte Carlo simulations. In the load estimation, the still water bending moment and wave-induced bending moment were calculated using a simplified formula of the International Association of Classification Societies-Common Structural Rules code and then modified with load parameters. The reliability index was estimated using a first-order reliability method considering the operating time, the duration of the ship in the alternate hold loading condition, and the severity of the corrosion rate. As a result, sagging conditions dominated the collapse mode. The reliability indexes were obtained for the observed cases, and the viability of the ship was assessed accordingly.","PeriodicalId":44435,"journal":{"name":"Curved and Layered Structures","volume":" ","pages":""},"PeriodicalIF":1.5,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45155127","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Bodol Momha Merlin, Djopkop Kouanang Landry, Amba Jean Chills, Nkongho Anyi Joseph, Zoa Ambassa, Nzengwa Robert
Abstract The article focuses on the influence of differential shrinkage linked by drying at the early-age displacements and strain distribution of a concrete ring specimen. Depending on the gradient of dimension changes through the thickness, tensile stress occurs near the exposed surface where drying is greater and thus results in strain gradients development. An experimental design was carried out on a concrete ring cast in laboratory conditions in order to monitor strains and displacements. Subsequently, a finite element method was used to simulate the ring’s behaviour in drying conditions. The gradient development linked by a non-uniform moisture distribution in the thickness is established by solving the non-linear partial differential drying equation with Mensi’s diffusion law. The stress and displacement analysis was modeled by three nodes curved shell FEM (CSFE-sh) based on strain approximation with the shell theory. Finally, the ring’s behaviour includes both differential shrinkage resulting in the mechanical and physical properties of gradients development in the thickness and the influence of prestressing, in which the tensile creep effects have a great influence. The comparison of experimental results with numerical simulation shows that drying and tensile creep phenomena have the most important influence on the early-age stress development in the walled ring.
{"title":"Investigation of differential shrinkage stresses in a revolution shell structure due to the evolving parameters of concrete","authors":"Bodol Momha Merlin, Djopkop Kouanang Landry, Amba Jean Chills, Nkongho Anyi Joseph, Zoa Ambassa, Nzengwa Robert","doi":"10.1515/cls-2022-0179","DOIUrl":"https://doi.org/10.1515/cls-2022-0179","url":null,"abstract":"Abstract The article focuses on the influence of differential shrinkage linked by drying at the early-age displacements and strain distribution of a concrete ring specimen. Depending on the gradient of dimension changes through the thickness, tensile stress occurs near the exposed surface where drying is greater and thus results in strain gradients development. An experimental design was carried out on a concrete ring cast in laboratory conditions in order to monitor strains and displacements. Subsequently, a finite element method was used to simulate the ring’s behaviour in drying conditions. The gradient development linked by a non-uniform moisture distribution in the thickness is established by solving the non-linear partial differential drying equation with Mensi’s diffusion law. The stress and displacement analysis was modeled by three nodes curved shell FEM (CSFE-sh) based on strain approximation with the shell theory. Finally, the ring’s behaviour includes both differential shrinkage resulting in the mechanical and physical properties of gradients development in the thickness and the influence of prestressing, in which the tensile creep effects have a great influence. The comparison of experimental results with numerical simulation shows that drying and tensile creep phenomena have the most important influence on the early-age stress development in the walled ring.","PeriodicalId":44435,"journal":{"name":"Curved and Layered Structures","volume":" ","pages":""},"PeriodicalIF":1.5,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45396520","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
O. Mursid, T. Tuswan, Samuel Samuel, A. Trimulyono, H. Yudo, N. Huda, H. Nubli, A. Prabowo
Abstract Pitting corrosion is the most common, dangerous, and destructive corrosion type in marine and offshore structures. This type of corrosion can reduce the strength of the ship plate, so investigating it using several numerical grounding scenarios is needed to determine the significant degradation of the strength of the structural plate. In this study, a finite element study was used to evaluate the influence of pitting corrosion location on the strength of the bottom plate ship in grounding simulation. This study simulated 14 scenarios using different pitting positions on the bottom plate. Finite element using explicit dynamic simulation in LS Dyna software was employed to evaluate the strength of the bottom plate on the ship. The output parameters, such as reaction force and plate deformation, were assessed to compare the grounding simulation results. The simulation indicates that the location of pitting corrosion will affect stress concentration, crack initiation, reaction force, and penetrating position when the crack nucleates. The result shows the critical position of the pit, which is located near the stress concentration ring (nearly 100 mm from the center of the plates) in the plain plates.
{"title":"Effect of pitting corrosion position to the strength of ship bottom plate in grounding incident","authors":"O. Mursid, T. Tuswan, Samuel Samuel, A. Trimulyono, H. Yudo, N. Huda, H. Nubli, A. Prabowo","doi":"10.1515/cls-2022-0199","DOIUrl":"https://doi.org/10.1515/cls-2022-0199","url":null,"abstract":"Abstract Pitting corrosion is the most common, dangerous, and destructive corrosion type in marine and offshore structures. This type of corrosion can reduce the strength of the ship plate, so investigating it using several numerical grounding scenarios is needed to determine the significant degradation of the strength of the structural plate. In this study, a finite element study was used to evaluate the influence of pitting corrosion location on the strength of the bottom plate ship in grounding simulation. This study simulated 14 scenarios using different pitting positions on the bottom plate. Finite element using explicit dynamic simulation in LS Dyna software was employed to evaluate the strength of the bottom plate on the ship. The output parameters, such as reaction force and plate deformation, were assessed to compare the grounding simulation results. The simulation indicates that the location of pitting corrosion will affect stress concentration, crack initiation, reaction force, and penetrating position when the crack nucleates. The result shows the critical position of the pit, which is located near the stress concentration ring (nearly 100 mm from the center of the plates) in the plain plates.","PeriodicalId":44435,"journal":{"name":"Curved and Layered Structures","volume":" ","pages":""},"PeriodicalIF":1.5,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47881569","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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