International Maritime Organization (IMO) has published technical circular (MSC/Circular. 834) including nonmandatory guidelines with five main criteria about engine room layout, design, and arrangement. The purpose of this study is to present the most important priority criteria of seafarers about engine room design according to the criteria from IMO MSC/Circular.834 guidelines. Since there are no obligations, the priority and importance of these criteria are not clearly emphasized. Therefore, the determination of seafarers’ priorities for arrangement in terms of safety and efficiency become important to make decision. For this, fuzzy Analytic Hierarchy Process (AHP) technique, which is one of the most used fuzzy Multiple Criteria Decision Making (MCDM)methods is employed. Maritime transportation, known for oldest and widespread transportation around the world, with 11 billion tons weight and 80% rate of world trade volume (UNCTAD 2019). Maritime transportation has many components and one of the most important and effective parts of these components are ships and seafarers. Because of the difficulty of ship conditions, ships should be present optimum working conditions for seafarers in order to achieve effective and safe operations on board. At the present time, there are previous studies about the difficulty of working studies on board. It is a scientific and cultural fact that seafarers are under higher risk of working conditions comparing to other jobs (Bloor et al. 2000; Havold 2005; Hetherington et al. 2006; Mallam et al. 2015). Due to this reason, International Maritime Organization (IMO) has made various regulations for years in order to improve seafarers’ safety and efficiency on board. One of the goals of these regulations is to design optimum working conditions on board for seafarers. Based on complex structure and having various danger conditions, engine room design is considerable to ensure safety and efficiency for engine room department seafarers.
{"title":"Priority Assessment of Key Factors of IMO-MSC/Circular.834 for Ship Engine Room Safety and Efficiency Based on Human Aspects","authors":"H. Ölmez, Selim Baştürk, Köksal Çolak","doi":"10.5957/jspd.10200029","DOIUrl":"https://doi.org/10.5957/jspd.10200029","url":null,"abstract":"\u0000 \u0000 International Maritime Organization (IMO) has published technical circular (MSC/Circular. 834) including nonmandatory guidelines with five main criteria about engine room layout, design, and arrangement. The purpose of this study is to present the most important priority criteria of seafarers about engine room design according to the criteria from IMO MSC/Circular.834 guidelines. Since there are no obligations, the priority and importance of these criteria are not clearly emphasized. Therefore, the determination of seafarers’ priorities for arrangement in terms of safety and efficiency become important to make decision. For this, fuzzy Analytic Hierarchy Process (AHP) technique, which is one of the most used fuzzy Multiple Criteria Decision Making (MCDM)methods is employed.\u0000 \u0000 \u0000 \u0000 Maritime transportation, known for oldest and widespread transportation around the world, with 11 billion tons weight and 80% rate of world trade volume (UNCTAD 2019). Maritime transportation has many components and one of the most important and effective parts of these components are ships and seafarers. Because of the difficulty of ship conditions, ships should be present optimum working conditions for seafarers in order to achieve effective and safe operations on board. At the present time, there are previous studies about the difficulty of working studies on board. It is a scientific and cultural fact that seafarers are under higher risk of working conditions comparing to other jobs (Bloor et al. 2000; Havold 2005; Hetherington et al. 2006; Mallam et al. 2015). Due to this reason, International Maritime Organization (IMO) has made various regulations for years in order to improve seafarers’ safety and efficiency on board. One of the goals of these regulations is to design optimum working conditions on board for seafarers. Based on complex structure and having various danger conditions, engine room design is considerable to ensure safety and efficiency for engine room department seafarers.\u0000","PeriodicalId":48791,"journal":{"name":"Journal of Ship Production and Design","volume":" ","pages":""},"PeriodicalIF":0.4,"publicationDate":"2021-10-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43898173","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Even though past efforts in computational fluid dynamics (CFD) simulations have shown great progress in the implementation of tubercles into aero-foils and turbines blades, incorporating these tubercles into marine vertical axis propellers is still comparatively less well understood. In general, the performance of marine propellers is highly related to the pressure and velocity distributions over the propeller blades. Since the presence of tubercles’ serrations in the blade leading edge can vary these distributions over the blade, the performance of the propellers can be enhanced. In this article, tubercle modifications are investigated in marine vertical axis propellers through the use of CFD simulation. To achieve this purpose, a complete procedure of CFD simulation using ANSYS FLUENT 16 is proposed. Obtained CFD results are validated using direct comparison with the previous analytical studies. Obtained performance characteristics of the modified vertical axis propeller are assessed against the available characteristics of the baseline one. The CFD results are found in a good agreement with the analytical ones. Moreover, the results demonstrate the improvement of the obtained performance of the modified vertical axis propeller compared to the baseline one in terms of increased thrust coefficient and higher efficiency over the considered range of advance ratio. Shallow waters, rivers, and seas; the presence of obstacles; the complexity of water routes; and the territorial orography require the availability of effective maneuverability to enhance marine propulsion compared to the traditional rudder-propeller system (Pasetto1 2013). In this context, the vertical axis propellers (VAP) can be a real and valid alternative to the rudder-propeller system (Chen 2007), allowing the ships to navigate in an effective way also in the difficult routing and in shallow water conditions (Carlton 2007). The VAP provides the ability to sail vessels in all sea conditions effectively. It maintains the ability to direct the thrust to 360° and, consequently, provides a better performance in terms of maneuverability, stop and crash maneuvers and higher efficiency. It is therefore necessary for all kinds of vessels requiring high level of maneuverability in congested waterways to be equipped with VAPs for ease, safety, and immediate response.
{"title":"Influence of Tubercle Modifications on the Performance of Marine Vertical Axis Propellers","authors":"M. Shouman, Mohamed M. Helal","doi":"10.5957/jspd.04190019","DOIUrl":"https://doi.org/10.5957/jspd.04190019","url":null,"abstract":"Even though past efforts in computational fluid dynamics (CFD) simulations have shown great progress in the implementation of tubercles into aero-foils and turbines blades, incorporating these tubercles into marine vertical axis propellers is still comparatively less well understood. In general, the performance of marine propellers is highly related to the pressure and velocity distributions over the propeller blades. Since the presence of tubercles’ serrations in the blade leading edge can vary these distributions over the blade, the performance of the propellers can be enhanced. In this article, tubercle modifications are investigated in marine vertical axis propellers through the use of CFD simulation. To achieve this purpose, a complete procedure of CFD simulation using ANSYS FLUENT 16 is proposed. Obtained CFD results are validated using direct comparison with the previous analytical studies. Obtained performance characteristics of the modified vertical axis propeller are assessed against the available characteristics of the baseline one. The CFD results are found in a good agreement with the analytical ones. Moreover, the results demonstrate the improvement of the obtained performance of the modified vertical axis propeller compared to the baseline one in terms of increased thrust coefficient and higher efficiency over the considered range of advance ratio.\u0000 \u0000 \u0000 Shallow waters, rivers, and seas; the presence of obstacles; the complexity of water routes; and the territorial orography require the availability of effective maneuverability to enhance marine propulsion compared to the traditional rudder-propeller system (Pasetto1 2013). In this context, the vertical axis propellers (VAP) can be a real and valid alternative to the rudder-propeller system (Chen 2007), allowing the ships to navigate in an effective way also in the difficult routing and in shallow water conditions (Carlton 2007). The VAP provides the ability to sail vessels in all sea conditions effectively. It maintains the ability to direct the thrust to 360° and, consequently, provides a better performance in terms of maneuverability, stop and crash maneuvers and higher efficiency. It is therefore necessary for all kinds of vessels requiring high level of maneuverability in congested waterways to be equipped with VAPs for ease, safety, and immediate response.\u0000","PeriodicalId":48791,"journal":{"name":"Journal of Ship Production and Design","volume":" ","pages":""},"PeriodicalIF":0.4,"publicationDate":"2021-09-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43516336","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Most shipyard companies maintain efficiency in all aspects of their business to survive. One of these aspects is ship production costs and their reduction. This study proposes a solution to this problem using an optimization method. A hatch cover composed of plates and stiffeners was selected as a case study. In this study, the mass and material cost of the hatch cover was optimized as an objective function using the Pareto approach with developed optimization methods. Plate thickness t, stiffener shape s, and plate material type m were selected as the design variables in this study along with some constraints. To estimate the optimal plate thickness, an expression of stress equations was Developed using an optimization technique. Furthermore, stiffener shape and plate material type selection were optimized using a genetic algorithm (GA). The results show that the optimization method is effective to decrease the mass and material cost of a hatch cover. The demand for new shipbuilding has decreased because of the effect of the economic crisis that hit almost every country in the world. Shipyard companies must think innovatively and creatively to survive under the pressure of this crisis by evaluating various studies and improvising new methods to achieve efficiency. One of the studies that has been performed examines the methods to reduce the fabrication cost of ship structures to stay profitable through the optimization of work hours, workflow production systems, and structural design.
{"title":"Study on Optimal Design of a Folding-Type Hatch Cover Considering Material Selection","authors":"Gerry Liston Putra, M. Kitamura, A. Takezawa","doi":"10.5957/jspd.12190063","DOIUrl":"https://doi.org/10.5957/jspd.12190063","url":null,"abstract":"\u0000 \u0000 Most shipyard companies maintain efficiency in all aspects of their business to survive. One of these aspects is ship production costs and their reduction. This study proposes a solution to this problem using an optimization method. A hatch cover composed of plates and stiffeners was selected as a case study. In this study, the mass and material cost of the hatch cover was optimized as an objective function using the Pareto approach with developed optimization methods. Plate thickness t, stiffener shape s, and plate material type m were selected as the design variables in this study along with some constraints. To estimate the optimal plate thickness, an expression of stress equations was Developed using an optimization technique. Furthermore, stiffener shape and plate material type selection were optimized using a genetic algorithm (GA). The results show that the optimization method is effective to decrease the mass and material cost of a hatch cover.\u0000 \u0000 \u0000 \u0000 The demand for new shipbuilding has decreased because of the effect of the economic crisis that hit almost every country in the world. Shipyard companies must think innovatively and creatively to survive under the pressure of this crisis by evaluating various studies and improvising new methods to achieve efficiency. One of the studies that has been performed examines the methods to reduce the fabrication cost of ship structures to stay profitable through the optimization of work hours, workflow production systems, and structural design.\u0000","PeriodicalId":48791,"journal":{"name":"Journal of Ship Production and Design","volume":" ","pages":""},"PeriodicalIF":0.4,"publicationDate":"2021-08-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45065250","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
A. Ebrahimi, P. O. Brett, S. O. Erikstad, B. Asbjørnslett
Complexity is discussed in design literature mainly through its negative and in some cases positive consequences. This article critically reviews and elaborates the effects of complexity on competitiveness in ship design, its directionality, and magnitude. The article introduces a model for the measurement of ship design complexity and ship design competitiveness based on predefined factors. Archival data of 100 ship design projects from eight different Norwegian designers are used as case study. Multivariate data analysis techniques are employed to study the research model. The results show a significant correlation between complexity and competitiveness in ship design, where the magnitude and directionality of influence vary among different complexity factors. Our findings provide a basis for enhancing complexity management in ship design. Continual technology improvements and market volatility with its associated uncertainties have a significant impact on and partly change ship design customers’ expectations. To be successful in such a market, not only does it require the development of competitive products but also the accompanying work processes and the organization or firm framing the development of the vessel solution are involved. Ulstein and Brett (2015) define ship design competitiveness in terms of doing the right thing (effectiveness), doing the right thing right (efficiency), and with the right resources (efficacy) to cover product, process, and firm aspects of competitiveness. To improve their success, ship design companies typically tend to focus on the introduction of new technologies, and, in some cases, extra functional capabilities, which have led to large and complex vessels over the years. To a lesser extent, ship designers have put emphasis on the overall needs of customers. Securing a higher overall performance yield of the ship design solution than peer vessels out in the market is not a common practice among ship designers; they rather focus on a typical and traditional subset of performances. The implications and the consequences of such strategies in ship design have led to a growing need for a new set of design tools and project-making skills, a more extensive design process with different disciplines involved, and many iterations in the design development process.
{"title":"Influence of Ship Design Complexity on Ship Design Competitiveness","authors":"A. Ebrahimi, P. O. Brett, S. O. Erikstad, B. Asbjørnslett","doi":"10.5957/jspd.08200020","DOIUrl":"https://doi.org/10.5957/jspd.08200020","url":null,"abstract":"Complexity is discussed in design literature mainly through its negative and in some cases positive consequences. This article critically reviews and elaborates the effects of complexity on competitiveness in ship design, its directionality, and magnitude. The article introduces a model for the measurement of ship design complexity and ship design competitiveness based on predefined factors. Archival data of 100 ship design projects from eight different Norwegian designers are used as case study. Multivariate data analysis techniques are employed to study the research model. The results show a significant correlation between complexity and competitiveness in ship design, where the magnitude and directionality of influence vary among different complexity factors. Our findings provide a basis for enhancing complexity management in ship design.\u0000 \u0000 \u0000 Continual technology improvements and market volatility with its associated uncertainties have a significant impact on and partly change ship design customers’ expectations. To be successful in such a market, not only does it require the development of competitive products but also the accompanying work processes and the organization or firm framing the development of the vessel solution are involved. Ulstein and Brett (2015) define ship design competitiveness in terms of doing the right thing (effectiveness), doing the right thing right (efficiency), and with the right resources (efficacy) to cover product, process, and firm aspects of competitiveness. To improve their success, ship design companies typically tend to focus on the introduction of new technologies, and, in some cases, extra functional capabilities, which have led to large and complex vessels over the years. To a lesser extent, ship designers have put emphasis on the overall needs of customers. Securing a higher overall performance yield of the ship design solution than peer vessels out in the market is not a common practice among ship designers; they rather focus on a typical and traditional subset of performances. The implications and the consequences of such strategies in ship design have led to a growing need for a new set of design tools and project-making skills, a more extensive design process with different disciplines involved, and many iterations in the design development process.\u0000","PeriodicalId":48791,"journal":{"name":"Journal of Ship Production and Design","volume":" ","pages":""},"PeriodicalIF":0.4,"publicationDate":"2021-08-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45701657","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
A design of risk prediction assessment is proposed to improve the safety and economy of ship-integrated electric propulsion system(SIEPS). Firstly, the article puts forward a multihidden Markov model (MHMM)–Viterbi algorithm to predict fault state probabilities of each component in the continuous time points in the future. Secondly, according to the influence of dynamic ocean condition, the fault states of the components of SIEPS are predicted by using the MHMM–Viterbi algorithm. Thirdly, the risk assessment system of network topology of SIEPS is designed, and power flow analysis under the abnormal condition is repeatedly calculated by using the MonteCarlo simulation. Finally, the article takes a SIEPS as an example and the risk prediction assessment results is given. With the establishment of increasingly stringent standards by the International Maritime Organization in terms of ship emissions and the increasing scarcity of petroleum resources, electric propulsion systems are gradually replacing internal combustion engines, which will become the future direction of ship power development. Electric propulsion ships do have many advantages such as high efficiency, high automation, environmental protection, energy saving, and emission reduction. However, ship-integrated electric propulsion system(SIEPS) is also the soft underbelly of electric propulsion ships. First of all, the complexity of the external environment factors such as high humidity and high salinity of ships (especially marine vessels) under long-term operating conditions, and the coupling of electromagnetic, thermal, and vibration signals of SIEPS will increase the failure rate of electrical equipment, thereby increasing the risk of SIEPS. Secondly, for electric propulsion ships, the SIEPS risk is likely to lead to chain failure of important systems such as power, control, navigation, resulting in the ship. Equipment and even personnel cause irreparable damage, causing fatal damage to electric propulsion ships. Therefore, in order to improve the safety, reliability, and economy of electric propulsion ships, it is necessary to carry out research on relevant technologies for SIEPS risk assessment (Wen et al. 2012; Guangfu et al. 2013).
为提高船舶综合电力推进系统(SIEPS)的安全性和经济性，提出了一种风险预测评估设计。首先，提出了一种多隐马尔可夫模型(MHMM) -Viterbi算法来预测未来连续时间点各部件的故障状态概率。其次，根据海洋动态条件的影响，采用MHMM-Viterbi算法对SIEPS各分量的故障状态进行预测;再次，设计了SIEPS网络拓扑风险评估体系，利用MonteCarlo仿真反复计算了异常工况下的潮流分析。最后，本文以SIEPS为例，给出了风险预测评价结果。随着国际海事组织对船舶排放标准的日益严格以及石油资源的日益匮乏，电力推进系统正在逐步取代内燃机，成为未来船舶动力发展的方向。电力推进船舶确实具有效率高、自动化程度高、环保节能减排等诸多优点。然而，船舶综合电力推进系统(SIEPS)也是电力推进船舶的软肋。首先，船舶(特别是海船)在长期运行状态下的高湿、高盐度等外部环境因素的复杂性，以及SIEPS的电磁、热、振动信号的耦合，会增加电气设备的故障率，从而增加SIEPS的风险。其次，对于电力推进船舶而言，SIEPS风险可能导致动力、控制、导航等重要系统发生连锁故障，导致船舶沉没。设备甚至人员造成不可弥补的损害，对电力推进船舶造成致命损害。因此，为了提高电力推进船舶的安全性、可靠性和经济性，有必要开展SIEPS风险评估的相关技术研究(Wen et al. 2012;Guangfu et al. 2013)。
{"title":"Design of Risk Prediction Assessment for Ship-Integrated Electric Propulsion System","authors":"Pengfei Zhi, Zhiyu Zhu, Wanlu Zhu, Qiu Haiyang","doi":"10.5957/jspd.12180058","DOIUrl":"https://doi.org/10.5957/jspd.12180058","url":null,"abstract":"A design of risk prediction assessment is proposed to improve the safety and economy of ship-integrated electric propulsion system(SIEPS). Firstly, the article puts forward a multihidden Markov model (MHMM)–Viterbi algorithm to predict fault state probabilities of each component in the continuous time points in the future. Secondly, according to the influence of dynamic ocean condition, the fault states of the components of SIEPS are predicted by using the MHMM–Viterbi algorithm. Thirdly, the risk assessment system of network topology of SIEPS is designed, and power flow analysis under the abnormal condition is repeatedly calculated by using the MonteCarlo simulation. Finally, the article takes a SIEPS as an example and the risk prediction assessment results is given.\u0000 \u0000 \u0000 With the establishment of increasingly stringent standards by the International Maritime Organization in terms of ship emissions and the increasing scarcity of petroleum resources, electric propulsion systems are gradually replacing internal combustion engines, which will become the future direction of ship power development.\u0000 Electric propulsion ships do have many advantages such as high efficiency, high automation, environmental protection, energy saving, and emission reduction. However, ship-integrated electric propulsion system(SIEPS) is also the soft underbelly of electric propulsion ships. First of all, the complexity of the external environment factors such as high humidity and high salinity of ships (especially marine vessels) under long-term operating conditions, and the coupling of electromagnetic, thermal, and vibration signals of SIEPS will increase the failure rate of electrical equipment, thereby increasing the risk of SIEPS. Secondly, for electric propulsion ships, the SIEPS risk is likely to lead to chain failure of important systems such as power, control, navigation, resulting in the ship. Equipment and even personnel cause irreparable damage, causing fatal damage to electric propulsion ships. Therefore, in order to improve the safety, reliability, and economy of electric propulsion ships, it is necessary to carry out research on relevant technologies for SIEPS risk assessment (Wen et al. 2012; Guangfu et al. 2013).\u0000","PeriodicalId":48791,"journal":{"name":"Journal of Ship Production and Design","volume":" ","pages":""},"PeriodicalIF":0.4,"publicationDate":"2021-08-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43146821","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
V. Bucci, G. Sulligoi, J. Chalfant, C. Chryssostomidis
Modern ships are highly complex technological systems and have a long and resource-intensive development cycle. Moreover, the final design must comply with many specific technical and regulatory requirements while constraining the capital and operational expenditures. Decisions made during the early stages of design have a large impact on ship functionality and determine the overall configuration of the ship; the advanced computational resources available today can be used to change the traditional approach to ship design, significantly improving the data available for these early-stage decisions. Moreover, the new methodologies can improve the ability to assess the impact of innovative technologies such as those inherent in the complete electrification of ships, and can simultaneously allow visualization of a three-dimensional (3D) virtual prototype of the designs. In this article, a methodological approach is presented that exemplifies these advantages.
{"title":"Evolution in Design Methodology for Complex Electric Ships","authors":"V. Bucci, G. Sulligoi, J. Chalfant, C. Chryssostomidis","doi":"10.5957/JSPD.08190045","DOIUrl":"https://doi.org/10.5957/JSPD.08190045","url":null,"abstract":"Modern ships are highly complex technological systems and have a long and resource-intensive development cycle. Moreover, the final design must comply with many specific technical and regulatory requirements while constraining the capital and operational expenditures. Decisions made during the early stages of design have a large impact on ship functionality and determine the overall configuration of the ship; the advanced computational resources available today can be used to change the traditional approach to ship design, significantly improving the data available for these early-stage decisions. Moreover, the new methodologies can improve the ability to assess the impact of innovative technologies such as those inherent in the complete electrification of ships, and can simultaneously allow visualization of a three-dimensional (3D) virtual prototype of the designs. In this article, a methodological approach is presented that exemplifies these advantages.","PeriodicalId":48791,"journal":{"name":"Journal of Ship Production and Design","volume":" ","pages":""},"PeriodicalIF":0.4,"publicationDate":"2021-07-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45452900","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Wen Huabing, Liu Wei, Junhua Guo, Kun Zhang, Li Yang, L. Yue
Since an inerter has been widely used in the field of vibration isolation, the combination of the inerter and the rubber part inevitably becomes a trend. In this work, a parallel inerter-spring-damper system (II-ISD) was introduced and analyzed for its performance on vibration isolation. Then, the optimal inertance-mass ratio and the frequency ratio at the minimum transmissibility were obtained. Based on the II-ISD system, an integrated vibration isolator was designed where the rubber part paralleled to the inerter, which was named as the inerter-rubber vibration isolator (IR). Then, its mechanical properties were simulated, and the mathematical model was established by considering the vibration isolation performance and the service life. Afterward, it was optimized by a programmed multi-objective genetic algorithm, and the optimal design parameters of IR were got finally. The experimental prototype of IR was processed, and its performance experiment was performed on the Mechanical Testing System (MTS) test bed. Experimental results show that the theoretical model of IR based on the II-ISD system is accurate; the resonant peak of IR is clearly lower than that of the rubber vibration isolator; the natural frequency decreases obviously. This work provides a design method for the serial product development, which has a practical engineering significance. With the development of machinery industry, vibrations (especially low frequency vibration) have become a big challenge for engineers (Xia et al. 2016a, 2016b; Sun et al. 2017). Scholars used various methods to weaken vibrations, such as the research of dynamic vibration absorber (Deng et al. 2006; Acar & Yilmaz 2012; Shen et al. 2016c, 2017) and rubber vibration isolator (Huang et al. 2014; Wang et al. 2014; Jin et al. 2015; Kim et al. 2015). In some special machinery areas, such as shipbuilding, wind power, and marine industry, the rubber vibration isolator has been commonly used and studied for years. However, a fatal shortcoming limits its development; that is, its vibration isolation performance at low frequencies is poor (Wen 2015). Therefore, the topic of solving this problem has been put on the agenda.
随着惯性装置在隔振领域的广泛应用，惯性装置与橡胶部件的结合不可避免地成为一种趋势。本文介绍了一种并联惯性弹簧阻尼器系统（Ⅱ-ISD），并对其隔振性能进行了分析。然后，得到了在最小传递率下的最佳惯性质量比和频率比。在Ⅱ-ISD系统的基础上，设计了一种橡胶部件与惯性体平行的集成隔振器，称为惯性体橡胶隔振器（IR）。然后，对其力学性能进行了仿真，并考虑隔振性能和使用寿命建立了数学模型。然后，利用程序化多目标遗传算法对其进行优化，最终得到了IR的最优设计参数。对红外光谱的实验样机进行了加工，并在MTS试验台上进行了性能实验。实验结果表明，基于Ⅱ-ISD系统的红外理论模型是准确的；IR的共振峰明显低于橡胶隔振器的共振峰；固有频率明显降低。该工作为系列产品开发提供了一种设计方法，具有实际的工程意义。随着机械工业的发展，振动（尤其是低频振动）已成为工程师面临的一大挑战（Xia et al.2016a，2016b；孙等人2017）。学者们使用了各种方法来削弱振动，如动态减振器的研究（Deng et al.2006；Acar和Yilmaz 2012；Shen et al.2016c，2017）和橡胶隔振器（Huang et al.2014；王等人2014；金等人2015；Kim等人2015）。在一些特殊机械领域，如造船、风电和海洋工业，橡胶隔振器已经被广泛使用和研究了多年。然而，一个致命的缺点限制了它的发展；即其低频隔振性能较差（温2015）。因此，解决这一问题的议题被提上了议事日程。
{"title":"Design and Experiment of Inerter-Rubber Vibration Isolator Based on Parallel Inerter-Spring-Damper System","authors":"Wen Huabing, Liu Wei, Junhua Guo, Kun Zhang, Li Yang, L. Yue","doi":"10.5957/JSPD.09180033","DOIUrl":"https://doi.org/10.5957/JSPD.09180033","url":null,"abstract":"Since an inerter has been widely used in the field of vibration isolation, the combination of the inerter and the rubber part inevitably becomes a trend. In this work, a parallel inerter-spring-damper system (II-ISD) was introduced and analyzed for its performance on vibration isolation. Then, the optimal inertance-mass ratio and the frequency ratio at the minimum transmissibility were obtained. Based on the II-ISD system, an integrated vibration isolator was designed where the rubber part paralleled to the inerter, which was named as the inerter-rubber vibration isolator (IR). Then, its mechanical properties were simulated, and the mathematical model was established by considering the vibration isolation performance and the service life. Afterward, it was optimized by a programmed multi-objective genetic algorithm, and the optimal design parameters of IR were got finally. The experimental prototype of IR was processed, and its performance experiment was performed on the Mechanical Testing System (MTS) test bed. Experimental results show that the theoretical model of IR based on the II-ISD system is accurate; the resonant peak of IR is clearly lower than that of the rubber vibration isolator; the natural frequency decreases obviously. This work provides a design method for the serial product development, which has a practical engineering significance.\u0000 \u0000 \u0000 With the development of machinery industry, vibrations (especially low frequency vibration) have become a big challenge for engineers (Xia et al. 2016a, 2016b; Sun et al. 2017). Scholars used various methods to weaken vibrations, such as the research of dynamic vibration absorber (Deng et al. 2006; Acar & Yilmaz 2012; Shen et al. 2016c, 2017) and rubber vibration isolator (Huang et al. 2014; Wang et al. 2014; Jin et al. 2015; Kim et al. 2015). In some special machinery areas, such as shipbuilding, wind power, and marine industry, the rubber vibration isolator has been commonly used and studied for years. However, a fatal shortcoming limits its development; that is, its vibration isolation performance at low frequencies is poor (Wen 2015). Therefore, the topic of solving this problem has been put on the agenda.\u0000","PeriodicalId":48791,"journal":{"name":"Journal of Ship Production and Design","volume":" ","pages":""},"PeriodicalIF":0.4,"publicationDate":"2021-05-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43912044","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Dong-sheng Zhao, Tianfei Zhang, Lele Kong, DaiFa Long, Yujun Liu
Automatic gas tungsten arc welding experiments of 5083 aluminum alloy were completed, to analyze the weld microstructure and mechanical properties. The influences of welding current, travel speed, frequency, and arc length on weld forming and mechanical properties were studied. When the welding current was 160 A, the travel speed was 380 mm/min, the frequency was 100 Hz, the arc length was 4 mm, and the maximum tensile strength of the welded joint was 296.9 MPa, which was 86.8% of the base metal’s tensile strength. The fracture elongation was 7.8%. No porosity was formed in the weld, but there were poor fusion problems. ER5356 welding wire can improve the problem of poor weld fusion and accommodate Mg element vaporization losses. When the wire feeding speed was 1200 mm/min, the tensile strength of the welded joint can be improved to 315.2 MPa, which was 92.2% of the base material’s tensile strength, and the fracture elongation was 8.5%. The tensile specimens fractured in the heat-affected zone. The fracture surface was characterized as plastic fracture. Specific strength of aluminum alloy is high, so aluminum alloys reduce the weight of the structure compared with steel structures. Aluminum alloys have a broad application prospect in aerospace, automotive, and marine industries based on their good corrosion resistance, low temperature resistance, good processability, and rich alloy system (Kuk et al. 2004; Wang & Zhang 2015; Canepa et al. 2018; Gaur et al. 2018; Qiang & Wang 2019). In recent years, to reduce the weight of the structure such as trimaran hull and improve speed, aluminum alloys have been more and more applied in shipbuilding. But there are many problems in the welding of aluminum alloy.
{"title":"Effect of ER5356 Welding Wire on Microstructure and Mechanical Properties of 5083 Aluminum Alloy GTAW Welded Joint","authors":"Dong-sheng Zhao, Tianfei Zhang, Lele Kong, DaiFa Long, Yujun Liu","doi":"10.5957/JSPD.10200026","DOIUrl":"https://doi.org/10.5957/JSPD.10200026","url":null,"abstract":"Automatic gas tungsten arc welding experiments of 5083 aluminum alloy were completed, to analyze the weld microstructure and mechanical properties. The influences of welding current, travel speed, frequency, and arc length on weld forming and mechanical properties were studied. When the welding current was 160 A, the travel speed was 380 mm/min, the frequency was 100 Hz, the arc length was 4 mm, and the maximum tensile strength of the welded joint was 296.9 MPa, which was 86.8% of the base metal’s tensile strength. The fracture elongation was 7.8%. No porosity was formed in the weld, but there were poor fusion problems. ER5356 welding wire can improve the problem of poor weld fusion and accommodate Mg element vaporization losses. When the wire feeding speed was 1200 mm/min, the tensile strength of the welded joint can be improved to 315.2 MPa, which was 92.2% of the base material’s tensile strength, and the fracture elongation was 8.5%. The tensile specimens fractured in the heat-affected zone. The fracture surface was characterized as plastic fracture.\u0000 \u0000 \u0000 Specific strength of aluminum alloy is high, so aluminum alloys reduce the weight of the structure compared with steel structures. Aluminum alloys have a broad application prospect in aerospace, automotive, and marine industries based on their good corrosion resistance, low temperature resistance, good processability, and rich alloy system (Kuk et al. 2004; Wang & Zhang 2015; Canepa et al. 2018; Gaur et al. 2018; Qiang & Wang 2019). In recent years, to reduce the weight of the structure such as trimaran hull and improve speed, aluminum alloys have been more and more applied in shipbuilding. But there are many problems in the welding of aluminum alloy.\u0000","PeriodicalId":48791,"journal":{"name":"Journal of Ship Production and Design","volume":" ","pages":""},"PeriodicalIF":0.4,"publicationDate":"2021-05-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42303184","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The design of successful water-based aircraft requires a close collaboration between the aeronautical engineers and naval architects, who perform high-speed towing tests, stability calculations, or computational fluid dynamics in support of the design. This article presents the fundamental design considerations of waterborne aircraft, which are outside of the typical educational scope of most naval architects, but which they are sometimes asked to address. These include 1) the hydrostatic and hydrodynamic problems associated with seaplane design, 2) early-stage methods for sizing the hull, 3) prediction techniques using archival data, and 4) hydrodynamic model testing procedures. Although a new design will often require substantial iteration to achieve the desired outcome, the information in this article will assist in developing a reasonable starting point for the design spiral and provides sufficient details for a hydrodynamic model testing facility to perform a successful series of model tests on the design. Although much of the work in this field dates from the 1940s, it is important to review this material in light of the current practices being used at hydrodynamic research facilities today. A detailed description of the model testing apparatus and procedure, used in a recent study at the U.S. Naval Academy, is presented to demonstrate the current applicability of these methods and some pitfalls that can be expected in testing. Today, there is a renewed interest in seaplane designs for both civilian and governmental applications worldwide. According to the Seaplane Pilots Association, there are approximately thirty-five thousand seaplane-rated pilots in the United States and between five and ten thousand operational seaplanes. Worldwide, larger seaplanes are used for firefighting, search and rescue applications, and cargo transportation.
{"title":"A Review of Hydrodynamic Design Methods for Seaplanes","authors":"M. Morabito","doi":"10.5957/JSPD.11180039","DOIUrl":"https://doi.org/10.5957/JSPD.11180039","url":null,"abstract":"The design of successful water-based aircraft requires a close collaboration between the aeronautical engineers and naval architects, who perform high-speed towing tests, stability calculations, or computational fluid dynamics in support of the design. This article presents the fundamental design considerations of waterborne aircraft, which are outside of the typical educational scope of most naval architects, but which they are sometimes asked to address. These include 1) the hydrostatic and hydrodynamic problems associated with seaplane design, 2) early-stage methods for sizing the hull, 3) prediction techniques using archival data, and 4) hydrodynamic model testing procedures. Although a new design will often require substantial iteration to achieve the desired outcome, the information in this article will assist in developing a reasonable starting point for the design spiral and provides sufficient details for a hydrodynamic model testing facility to perform a successful series of model tests on the design. Although much of the work in this field dates from the 1940s, it is important to review this material in light of the current practices being used at hydrodynamic research facilities today. A detailed description of the model testing apparatus and procedure, used in a recent study at the U.S. Naval Academy, is presented to demonstrate the current applicability of these methods and some pitfalls that can be expected in testing.\u0000 \u0000 \u0000 Today, there is a renewed interest in seaplane designs for both civilian and governmental applications worldwide. According to the Seaplane Pilots Association, there are approximately thirty-five thousand seaplane-rated pilots in the United States and between five and ten thousand operational seaplanes. Worldwide, larger seaplanes are used for firefighting, search and rescue applications, and cargo transportation.\u0000","PeriodicalId":48791,"journal":{"name":"Journal of Ship Production and Design","volume":" ","pages":""},"PeriodicalIF":0.4,"publicationDate":"2021-02-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44683307","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Structural steel renewal in ship repairing is a routine work throughout the service/ operational life of a ship. Prior information about the renewal quantity helps the shipowners to allocate an appropriate budget and the shipyard to prepare the proper ship repairing schedule. It, in turn, helps the shipowners make a financial commitment for cargo. Likewise, prior information about the location of steel renewal works can help the shipowners to prepare the ship before going to the shipyard and the latter to plan for the required logistics. By doing so, the shipowners would be able to save cost in terms of less idle time in the shipyard. The latter can also increase the revenue in terms of minimizing mobilization time. Structural steel renewal location-related information for 123 cargo ships of various ages, deadweights, and types were collected from a single shipyard. Data of renewal locations of selected structural members were analyzed and presented in both tabular and graphical forms. The intention was to show the behavior of renewal locations with respect to the ship’s dimension appropriate for respective structural members, age, and length of the ship. In this article, the authors have attempted to identify and establish the possible root causes that influence the renewal locations and also to investigate and suggest the potential interrelationships between renewal locations, age, length, and type.
{"title":"Analysis of Structural Steel Renewal Locations in Ship Repairing","authors":"A. Dev, Makaraksha Saha","doi":"10.5957/JSPD.01190004","DOIUrl":"https://doi.org/10.5957/JSPD.01190004","url":null,"abstract":"Structural steel renewal in ship repairing is a routine work throughout the service/ operational life of a ship. Prior information about the renewal quantity helps the shipowners to allocate an appropriate budget and the shipyard to prepare the proper ship repairing schedule. It, in turn, helps the shipowners make a financial commitment for cargo. Likewise, prior information about the location of steel renewal works can help the shipowners to prepare the ship before going to the shipyard and the latter to plan for the required logistics. By doing so, the shipowners would be able to save cost in terms of less idle time in the shipyard. The latter can also increase the revenue in terms of minimizing mobilization time. Structural steel renewal location-related information for 123 cargo ships of various ages, deadweights, and types were collected from a single shipyard. Data of renewal locations of selected structural members were analyzed and presented in both tabular and graphical forms. The intention was to show the behavior of renewal locations with respect to the ship’s dimension appropriate for respective structural members, age, and length of the ship. In this article, the authors have attempted to identify and establish the possible root causes that influence the renewal locations and also to investigate and suggest the potential interrelationships between renewal locations, age, length, and type.","PeriodicalId":48791,"journal":{"name":"Journal of Ship Production and Design","volume":"37 1","pages":"1-36"},"PeriodicalIF":0.4,"publicationDate":"2021-02-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48343484","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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