Abstract Viscoelastic composites are strong and handle vibration damping quite well, which allows them to be used in a wide variety of applications. Thus, there is a need to determine the optimal amount of fiber to ensure high mechanical and dynamic performance with as little interference as possible. The purpose of this work is to find the most appropriate percentage of organic fiber – cellulose derived from corn stalks in a polylactic acid matrix, studying the changes in damping characteristics, tensile strength, bend-test. As parameters for comparison, the coefficient of bending and breaking strength, modules of accumulation and losses, factor C were chosen. It was found that strength indicators decrease with fiber fraction growth. While the damping factor at the glass transition temperature increases. In order to confirm the results obtained, the calculation of the C factor was used. The study investigates the damping factor’s dependence on the mechanical properties. It is shown that there is a correlation between moduli and bending strength with increasing fiber fraction. The scientific novelty of this work is the study of natural viscoelastic composites with different proportions of reinforcing fibers based on mechanical and dynamic characteristics in order to create and apply biodegradable viscoelastic composites in various fields.
{"title":"Determination of the dynamic performance of natural viscoelastic composites with different proportions of reinforcing fibers","authors":"S. Shlykov, R. Rogulin, S. Kondrashev","doi":"10.1515/cls-2022-0011","DOIUrl":"https://doi.org/10.1515/cls-2022-0011","url":null,"abstract":"Abstract Viscoelastic composites are strong and handle vibration damping quite well, which allows them to be used in a wide variety of applications. Thus, there is a need to determine the optimal amount of fiber to ensure high mechanical and dynamic performance with as little interference as possible. The purpose of this work is to find the most appropriate percentage of organic fiber – cellulose derived from corn stalks in a polylactic acid matrix, studying the changes in damping characteristics, tensile strength, bend-test. As parameters for comparison, the coefficient of bending and breaking strength, modules of accumulation and losses, factor C were chosen. It was found that strength indicators decrease with fiber fraction growth. While the damping factor at the glass transition temperature increases. In order to confirm the results obtained, the calculation of the C factor was used. The study investigates the damping factor’s dependence on the mechanical properties. It is shown that there is a correlation between moduli and bending strength with increasing fiber fraction. The scientific novelty of this work is the study of natural viscoelastic composites with different proportions of reinforcing fibers based on mechanical and dynamic characteristics in order to create and apply biodegradable viscoelastic composites in various fields.","PeriodicalId":44435,"journal":{"name":"Curved and Layered Structures","volume":"9 1","pages":"116 - 123"},"PeriodicalIF":1.5,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44019733","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 With the development of simulation technology and programs, it became necessary to study the models that control equations’ solutions and influence the results. The models having control over solving equations of multiple phases and materials are investigated. They include (Volume of Fluid (VOF), mixture, Eulerian) controlling the governing equations. The study was conducted depending on the boiling point of the water. The activation of these three models is carried out to find out which one is better for solving the issue of boiling compared to previous numerical and empirical research with the study of the surface tension coefficient that affects the behavior of phases in a contaminated manner. The best model explored in the case of boiling is VOF for the merging of steam bubbles, the velocity of flows 0.257 m/s for both water and steam, and the phase transition. The effectiveness of the VOF model is mirrored by higher efficiency and accuracy of the solution with velocity 0.257 m/s and volume fraction 0.9997. The activation of the surface tension factor 0.072 property simulates the real conditions surrounding the materials used in boiling, but it significantly increases the turbulence and distribution of gas bubbles.
{"title":"CFD Comparison of multiphase models in the pool boiling state","authors":"Suleiman MJ. Enjadat","doi":"10.1515/cls-2022-0029","DOIUrl":"https://doi.org/10.1515/cls-2022-0029","url":null,"abstract":"Abstract With the development of simulation technology and programs, it became necessary to study the models that control equations’ solutions and influence the results. The models having control over solving equations of multiple phases and materials are investigated. They include (Volume of Fluid (VOF), mixture, Eulerian) controlling the governing equations. The study was conducted depending on the boiling point of the water. The activation of these three models is carried out to find out which one is better for solving the issue of boiling compared to previous numerical and empirical research with the study of the surface tension coefficient that affects the behavior of phases in a contaminated manner. The best model explored in the case of boiling is VOF for the merging of steam bubbles, the velocity of flows 0.257 m/s for both water and steam, and the phase transition. The effectiveness of the VOF model is mirrored by higher efficiency and accuracy of the solution with velocity 0.257 m/s and volume fraction 0.9997. The activation of the surface tension factor 0.072 property simulates the real conditions surrounding the materials used in boiling, but it significantly increases the turbulence and distribution of gas bubbles.","PeriodicalId":44435,"journal":{"name":"Curved and Layered Structures","volume":"9 1","pages":"382 - 389"},"PeriodicalIF":1.5,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42719445","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 Single mode is one of the most practical applications in microwave propagations because of its high mode resolution and low transmission loss. In this paper, the single mode graphene material was implemented in slab waveguide to study the performance and optical properties of graphene material; the parameters that affect these models were found to be the cut-off frequency, attenuation wavenumbers, modes numbers, skin depth, angles incident, and propagation wave numbers. The effectiveness of these factors was simulated and analyzed using MATLAB software program. In this paper, the carriers were generated using nano-graphene; the optical carrier source provided seven carriers with the frequency spacing of 4.9682 GHz. After splitting the carriers using optical demultiplexer, these carriers were modulated independently using optical Quadrature phase shift keying (QPSK) modulators at symbol rate equal to 4.9682 Gsymbol/s; this matches the frequency spacing of the carriers. Under this argument, the total data rate was equal to 2*7*4.9682 Gsymbol/s = 69.5548 Gbit/s, and the total bandwidth was 34.774 GHz. These carriers were found to work in optical communication with high data rate.
{"title":"Generate high data rate of optical carries by using nanomaterial graphene in slab waveguide","authors":"Saib Thiab Alwan, O. A. Mahmood, Tahreer Mahmood","doi":"10.1515/cls-2022-0015","DOIUrl":"https://doi.org/10.1515/cls-2022-0015","url":null,"abstract":"Abstract Single mode is one of the most practical applications in microwave propagations because of its high mode resolution and low transmission loss. In this paper, the single mode graphene material was implemented in slab waveguide to study the performance and optical properties of graphene material; the parameters that affect these models were found to be the cut-off frequency, attenuation wavenumbers, modes numbers, skin depth, angles incident, and propagation wave numbers. The effectiveness of these factors was simulated and analyzed using MATLAB software program. In this paper, the carriers were generated using nano-graphene; the optical carrier source provided seven carriers with the frequency spacing of 4.9682 GHz. After splitting the carriers using optical demultiplexer, these carriers were modulated independently using optical Quadrature phase shift keying (QPSK) modulators at symbol rate equal to 4.9682 Gsymbol/s; this matches the frequency spacing of the carriers. Under this argument, the total data rate was equal to 2*7*4.9682 Gsymbol/s = 69.5548 Gbit/s, and the total bandwidth was 34.774 GHz. These carriers were found to work in optical communication with high data rate.","PeriodicalId":44435,"journal":{"name":"Curved and Layered Structures","volume":"9 1","pages":"187 - 192"},"PeriodicalIF":1.5,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47655627","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 In this paper, the effect of mixed convection on the flow behavior and heat transfer around a circular cylinder disclosed to a vertically upward laminar air stream is numerically examine. The buoyancy-aided flow is utilized to eliminate and control the vortex shedding of the cylinder. The influence of the Grashof number, 0 ≤ Gr ≤ 6000, the flow and thermal patterns, as well as the local and mean Nusselt number, is investigated at a constant Reynolds number of 100. The unsteady Navier-Stokes’s equations are solved employing a finite-volume method to simulate numerically the velocity and temperature fields in time and space. The results showed periodic instability in the flow and thermal fields for a range of Grashof number Gr ≤ 1300. Also, there is critical value of Grashof number for stopping this instability and the vortex shedding formed behind the cylinder, by the effect of heating. Thus, by increasing Grashof number between 1400 ≤ Gr ≤ 4000, the periodic flow vanishes and converts into steady flow with twin eddies attached to the cylinder from the back. Furthermore, as Grashof number increases behind Gr ≥ 5000, the flow becomes completely attached to the cylinder surface without any separation.
{"title":"Mixed convection around a circular cylinder in a buoyancy-assisting flow","authors":"H. S. Majdi, M. Mashkour, L. Habeeb, M. Ilic","doi":"10.1515/cls-2022-0008","DOIUrl":"https://doi.org/10.1515/cls-2022-0008","url":null,"abstract":"Abstract In this paper, the effect of mixed convection on the flow behavior and heat transfer around a circular cylinder disclosed to a vertically upward laminar air stream is numerically examine. The buoyancy-aided flow is utilized to eliminate and control the vortex shedding of the cylinder. The influence of the Grashof number, 0 ≤ Gr ≤ 6000, the flow and thermal patterns, as well as the local and mean Nusselt number, is investigated at a constant Reynolds number of 100. The unsteady Navier-Stokes’s equations are solved employing a finite-volume method to simulate numerically the velocity and temperature fields in time and space. The results showed periodic instability in the flow and thermal fields for a range of Grashof number Gr ≤ 1300. Also, there is critical value of Grashof number for stopping this instability and the vortex shedding formed behind the cylinder, by the effect of heating. Thus, by increasing Grashof number between 1400 ≤ Gr ≤ 4000, the periodic flow vanishes and converts into steady flow with twin eddies attached to the cylinder from the back. Furthermore, as Grashof number increases behind Gr ≥ 5000, the flow becomes completely attached to the cylinder surface without any separation.","PeriodicalId":44435,"journal":{"name":"Curved and Layered Structures","volume":"9 1","pages":"81 - 95"},"PeriodicalIF":1.5,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47982765","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 Epoxies as a thermoset polymer have got a great attention in different applications. To elaborate their employing and surmount their brittleness, many polymers were blended with them. The results confirm that the good mechanical properties are obtained when 6wt% of Polysulfide Rubber (PSR) is blended with epoxy and reinforced with fiber glass. The effect of rubber and glass fiber on the viscoelastic properties of epoxy were investigated using creep-recovery data under different stress levels (5, 10, 15 and 20 MPa) and temperatures (30, 50, 70 and 90°C). Polysulfide addition caused larger creep and creep recovery. In addition, the creep resistance of glass fiber reinforced blend was significantly enhanced.
{"title":"Viscoelastic behavior of glass fiber reinforced rubber-modified epoxy","authors":"Adnan Abbass Al-Azzawi","doi":"10.1515/cls-2022-0030","DOIUrl":"https://doi.org/10.1515/cls-2022-0030","url":null,"abstract":"Abstract Epoxies as a thermoset polymer have got a great attention in different applications. To elaborate their employing and surmount their brittleness, many polymers were blended with them. The results confirm that the good mechanical properties are obtained when 6wt% of Polysulfide Rubber (PSR) is blended with epoxy and reinforced with fiber glass. The effect of rubber and glass fiber on the viscoelastic properties of epoxy were investigated using creep-recovery data under different stress levels (5, 10, 15 and 20 MPa) and temperatures (30, 50, 70 and 90°C). Polysulfide addition caused larger creep and creep recovery. In addition, the creep resistance of glass fiber reinforced blend was significantly enhanced.","PeriodicalId":44435,"journal":{"name":"Curved and Layered Structures","volume":"9 1","pages":"390 - 395"},"PeriodicalIF":1.5,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41869747","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 The tunnel lining systems act as lines of defence against the forces and geotechnical situations. The use of precast concrete tunnel linings (PCTLs) has been escalating due to its effective and economical installation process. The tunnels usually suffer from the premature deterioration due to corrosion of the reinforcement and thus need maintenance. Corrosion leads to the distress in PCTL leading to the cracking and finally the scaling of concrete. This study aims to assess the structural durability performance of reactive powder concrete (RPC) as the material of tunnel lining segments compared to reinforced concrete (RC) and high performance concrete (HPC). The numerical findings indicated that the maximum load capacity of PRC-PCTL segments was greater than that of the corresponding RC and HPC segments. Regarding the findings, PRC is a very significant option for conventional segments. The high strength of PRC can decrease the thickness of the PCTL segments, resulting in the decreased material cost. Also, PRC-PCTL segments can eliminate the laborious and costly production of RC segments and mitigate the corrosion damage and thus enhance the service life of lining segments.
{"title":"Three-dimensional numerical study of the reactive powder concrete segments in tunnel lining","authors":"Hajer Satih Abbas, Maadh Imad Salman Al-Rubaye, Sarra’a Dhiya’a Jaafer, Bassam farman bassam, Abdelmajeed Alkasassbeh","doi":"10.1515/cls-2022-0022","DOIUrl":"https://doi.org/10.1515/cls-2022-0022","url":null,"abstract":"Abstract The tunnel lining systems act as lines of defence against the forces and geotechnical situations. The use of precast concrete tunnel linings (PCTLs) has been escalating due to its effective and economical installation process. The tunnels usually suffer from the premature deterioration due to corrosion of the reinforcement and thus need maintenance. Corrosion leads to the distress in PCTL leading to the cracking and finally the scaling of concrete. This study aims to assess the structural durability performance of reactive powder concrete (RPC) as the material of tunnel lining segments compared to reinforced concrete (RC) and high performance concrete (HPC). The numerical findings indicated that the maximum load capacity of PRC-PCTL segments was greater than that of the corresponding RC and HPC segments. Regarding the findings, PRC is a very significant option for conventional segments. The high strength of PRC can decrease the thickness of the PCTL segments, resulting in the decreased material cost. Also, PRC-PCTL segments can eliminate the laborious and costly production of RC segments and mitigate the corrosion damage and thus enhance the service life of lining segments.","PeriodicalId":44435,"journal":{"name":"Curved and Layered Structures","volume":"9 1","pages":"286 - 294"},"PeriodicalIF":1.5,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41675245","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}
Feng Qiu, J. Qiu, Heng Feng, Huajie Wang, H. Qian, Xiao-fei Jin, Kai-ming Wang, F. Fan
Abstract The angle steel member is the most commonly used component form of the transmission tower structure. Considering its connection characteristics, we must deal with its stability analysis under semi-rigid constraint conditions for the proper study of the overall structure’s mechanical performance. Therefore, in order to establish a simple and high-precision method suitable for the ultimate bearing capacity analysis of the transmission tower, we build the refined finite element models of typical steel tower joints, analyze its moment-rotation curve and utilize simulation technique of spring elements to acquire the calculation method of its single angle stability bearing capacity, which is considering initial imperfection and residual stress. Furthermore, we analyze its bearing capacity under different constraint conditions such as rigid, semi-rigid and articulated connection. The results show that it is necessary to consider joint stiffness in the bearing capacity analyses. Finally, it’s confirmed that the calculation results of this method agree well with the experimental data, which validates its high accuracy. Therefore, the method provides technical support for high efficient component stability simulation in overall stability analyses of the transmission steel tower.
{"title":"Calculation method of stability bearing capacity of transmission tower angle steel considering semi-rigid constraint","authors":"Feng Qiu, J. Qiu, Heng Feng, Huajie Wang, H. Qian, Xiao-fei Jin, Kai-ming Wang, F. Fan","doi":"10.1515/cls-2022-0017","DOIUrl":"https://doi.org/10.1515/cls-2022-0017","url":null,"abstract":"Abstract The angle steel member is the most commonly used component form of the transmission tower structure. Considering its connection characteristics, we must deal with its stability analysis under semi-rigid constraint conditions for the proper study of the overall structure’s mechanical performance. Therefore, in order to establish a simple and high-precision method suitable for the ultimate bearing capacity analysis of the transmission tower, we build the refined finite element models of typical steel tower joints, analyze its moment-rotation curve and utilize simulation technique of spring elements to acquire the calculation method of its single angle stability bearing capacity, which is considering initial imperfection and residual stress. Furthermore, we analyze its bearing capacity under different constraint conditions such as rigid, semi-rigid and articulated connection. The results show that it is necessary to consider joint stiffness in the bearing capacity analyses. Finally, it’s confirmed that the calculation results of this method agree well with the experimental data, which validates its high accuracy. Therefore, the method provides technical support for high efficient component stability simulation in overall stability analyses of the transmission steel tower.","PeriodicalId":44435,"journal":{"name":"Curved and Layered Structures","volume":"9 1","pages":"202 - 211"},"PeriodicalIF":1.5,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43741459","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 With the development of fiber technology on which the composite materials depend mainly was necessary to improve the rigidity, durability, and heat transfer in the areas of heating and cooling technologies. The effect of the fatigue phenomenon on composite materials using carbon fibers is studied. In this research paper, work was performed to study the improvement in the bearing capacity of the stress test sample with the addition of carbon fibers at different angles. The stresses affecting the test specimen are cylindrical with a length of 10 cm. The results proved that the best arrangement of the carbon fibers in the form of triple layers starting from the center of the cylinder circle to the outside was the share of the arrangement layer 45, 0, 0, where the lowest value was the number of fatigue life cycles, 2349 cycles in the bending test, as the amount of stress that this case reached was 6.1×108 Pa compared to the rest of the studied cases.
{"title":"Optimization of fatigue life in laminated composite plates","authors":"B. Ahmed","doi":"10.1515/cls-2022-0183","DOIUrl":"https://doi.org/10.1515/cls-2022-0183","url":null,"abstract":"Abstract With the development of fiber technology on which the composite materials depend mainly was necessary to improve the rigidity, durability, and heat transfer in the areas of heating and cooling technologies. The effect of the fatigue phenomenon on composite materials using carbon fibers is studied. In this research paper, work was performed to study the improvement in the bearing capacity of the stress test sample with the addition of carbon fibers at different angles. The stresses affecting the test specimen are cylindrical with a length of 10 cm. The results proved that the best arrangement of the carbon fibers in the form of triple layers starting from the center of the cylinder circle to the outside was the share of the arrangement layer 45, 0, 0, where the lowest value was the number of fatigue life cycles, 2349 cycles in the bending test, as the amount of stress that this case reached was 6.1×108 Pa compared to the rest of the studied cases.","PeriodicalId":44435,"journal":{"name":"Curved and Layered Structures","volume":"9 1","pages":"425 - 441"},"PeriodicalIF":1.5,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45642003","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 quadrilateral flat-shell element is developed for analysing the deflections, stresses and natural frequencies along with their allied mode shapes of cylindrical, spherical, and conical shell panels made up of layered composite and sandwich material. The developed element (DKZigTS1) is based on zigzag theory and has seven local as well as global DOF per node. The concept of obtaining transformation matrix is used for transforming actions and reactions from local to global direction to convert the plate bending into a flat-shell element. The two separate coordinate systems are used to transform rotational and translational degrees-of-freedom (DOF), from local to global direction. The local translational DOF are transformed to global Cartesian coordinates (x, y, z) and the local rotational DOF are transformed to the surface coordinate system (ξ1, ξ2, ξ3), in which ξ3 is perpendicular to the surface. The DKZigTS1 element gives fairly accurate results that align with the 2D analytical and the 3D elasticity solutions, reported in the literature for moderately thick and thick shell panel. The present results are also in good agreement with the 3D finite element solutions for shallow and deep shell panels having various material properties, boundary restrained environments, and geometrical shapes considered in this study.
摘要建立了一种四边形平壳单元，用于分析由层状复合材料和夹层材料组成的圆柱、球形和锥形壳板的挠度、应力和固有频率及其相关振型。所开发的元件(DKZigTS1)基于之字形理论，每个节点具有7个局部自由度和全局自由度。利用变换矩阵的概念，将作用和反作用从局部方向转化为全局方向，将弯曲板转化为平壳单元。两个独立的坐标系用于从局部方向到全局方向的旋转和平移自由度(DOF)转换。将局部平移DOF变换为全局笛卡尔坐标系(x, y, z)，将局部旋转DOF变换为曲面坐标系(ξ1， ξ2， ξ3)，其中ξ3垂直于曲面。DKZigTS1单元给出了相当准确的结果，与2D分析和3D弹性解决方案一致，在中等厚度和厚壳板的文献中报道。本文的结果也与本研究中考虑的具有不同材料性能、边界约束环境和几何形状的浅壳板和深壳板的三维有限元解相吻合。
{"title":"A quadrilateral flat-shell element for the static and dynamic analysis of composite and sandwich cylindrical, spherical and conical shell panels","authors":"V. Dagade, Shripad Kulkarni","doi":"10.1515/cls-2022-0025","DOIUrl":"https://doi.org/10.1515/cls-2022-0025","url":null,"abstract":"Abstract A quadrilateral flat-shell element is developed for analysing the deflections, stresses and natural frequencies along with their allied mode shapes of cylindrical, spherical, and conical shell panels made up of layered composite and sandwich material. The developed element (DKZigTS1) is based on zigzag theory and has seven local as well as global DOF per node. The concept of obtaining transformation matrix is used for transforming actions and reactions from local to global direction to convert the plate bending into a flat-shell element. The two separate coordinate systems are used to transform rotational and translational degrees-of-freedom (DOF), from local to global direction. The local translational DOF are transformed to global Cartesian coordinates (x, y, z) and the local rotational DOF are transformed to the surface coordinate system (ξ1, ξ2, ξ3), in which ξ3 is perpendicular to the surface. The DKZigTS1 element gives fairly accurate results that align with the 2D analytical and the 3D elasticity solutions, reported in the literature for moderately thick and thick shell panel. The present results are also in good agreement with the 3D finite element solutions for shallow and deep shell panels having various material properties, boundary restrained environments, and geometrical shapes considered in this study.","PeriodicalId":44435,"journal":{"name":"Curved and Layered Structures","volume":"9 1","pages":"320 - 344"},"PeriodicalIF":1.5,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42007359","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 This paper presents a numerical procedure based on the finite element (FE) method using ANSYS Workbench software to analyse fatigue phenomena in ship structures. Fatigue failure prediction is used as a stress–life approach, when the stress is still in a linear area. This condition is frequently referred as high-cycle fatigue. Five geometric shapes taken from midship points on the structure of a ship are sampled. There are four types of materials: HSLA SAE 950X, medium-carbon steel, SAE 316L, and SAE 304L. The types of loading imposed on each sample include three conditions: zero-based, zero mean, and ratio. Mesh convergence analysis is conducted to determine the most effective mesh shape and size for analysing the structure. The results showed that the configuration of the geometric shapes, materials used, loading schemes, and mean stress theory affect the fatigue characteristics of the structure.
{"title":"Assessment of ship structure under fatigue loading: FE benchmarking and extended performance analysis","authors":"Aprianur Fajri, A. Prabowo, N. Muhayat","doi":"10.1515/cls-2022-0014","DOIUrl":"https://doi.org/10.1515/cls-2022-0014","url":null,"abstract":"Abstract This paper presents a numerical procedure based on the finite element (FE) method using ANSYS Workbench software to analyse fatigue phenomena in ship structures. Fatigue failure prediction is used as a stress–life approach, when the stress is still in a linear area. This condition is frequently referred as high-cycle fatigue. Five geometric shapes taken from midship points on the structure of a ship are sampled. There are four types of materials: HSLA SAE 950X, medium-carbon steel, SAE 316L, and SAE 304L. The types of loading imposed on each sample include three conditions: zero-based, zero mean, and ratio. Mesh convergence analysis is conducted to determine the most effective mesh shape and size for analysing the structure. The results showed that the configuration of the geometric shapes, materials used, loading schemes, and mean stress theory affect the fatigue characteristics of the structure.","PeriodicalId":44435,"journal":{"name":"Curved and Layered Structures","volume":"9 1","pages":"163 - 186"},"PeriodicalIF":1.5,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44391441","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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