Pub Date : 2005-12-01DOI: 10.2534/JJASNAOE1968.2003.193_75
T. Terasaki, Masaru Mizukami, M. Nakatani, M. Ohsawa
For automatization of the line heating work that is a basic technology in making curved surfaces of ships it needs to evaluate transverse shrinkage generated by triangle heating quantitatively. In this paper, techniques were examined in triangle heating tests and an estimation method using FEM analyses were developed in the first place. Secondly numerical simulations of triangle heating discussed effects of line heating factors that were curvature radius in the transverse direction, water-cooling and heating length. It was concluded that curvature radius in the transverse direction had least effect in transverse shrinkage and water cooling following the heating touch led to efficient shrinkage. And as the parameter value of heat input in the panel end part was increasing with varying travel speed, transverse shrinkage generated lager, so that it was approximately proportional to the parameter value. The maximum shrinkage was achieved when heating length was from 0.3 to 0.4 times as long as plate width.
{"title":"Effect of line heating factors on transverse shrinkage generated by triangle heating","authors":"T. Terasaki, Masaru Mizukami, M. Nakatani, M. Ohsawa","doi":"10.2534/JJASNAOE1968.2003.193_75","DOIUrl":"https://doi.org/10.2534/JJASNAOE1968.2003.193_75","url":null,"abstract":"For automatization of the line heating work that is a basic technology in making curved surfaces of ships it needs to evaluate transverse shrinkage generated by triangle heating quantitatively. In this paper, techniques were examined in triangle heating tests and an estimation method using FEM analyses were developed in the first place. Secondly numerical simulations of triangle heating discussed effects of line heating factors that were curvature radius in the transverse direction, water-cooling and heating length. It was concluded that curvature radius in the transverse direction had least effect in transverse shrinkage and water cooling following the heating touch led to efficient shrinkage. And as the parameter value of heat input in the panel end part was increasing with varying travel speed, transverse shrinkage generated lager, so that it was approximately proportional to the parameter value. The maximum shrinkage was achieved when heating length was from 0.3 to 0.4 times as long as plate width.","PeriodicalId":321056,"journal":{"name":"Journal of the Society of Naval Architects of Japan","volume":"48 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2005-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123110379","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}
Pub Date : 2004-12-01DOI: 10.2534/JJASNAOE1968.2004.196_1
M. Arai, H. Nishihara
In various contexts of the shipbuilding industry as well as in the marine transportation industry, the relocation of objects such as steel plates, containers, etc. by using cranes is a common task. In these operations, crane operators are faced with the problem of starting with a given distribution of objects and restacking them in order to achieve a desired distribution using the least possible effort or movement of the crane. This type of problem involves a practically infinite number of solutions, since the possible combinations of operational order are so numerous. Therefore, it is difficult for the operator to determine the optimal sequence from the candidate processes, and it also is difficult to present a general method that can solve this problem with high degrees of efficiency and reliability. As a result, in practical situations the crane operators on site usually decide the sequence according to their experience and intuition. However, sometimes the planning of the crane operation process is very troublesome and time consuming and is thought to be not necessarily suitable for human beings.In this study we apply a genetic algorithm (GA) that excels at finding solutions to combinatory problems. The sequence of a crane's operation is represented in string expression and with the merit of a population search (i.e., a simultaneous multi-point search) of the GA, excellent operations were efficiently obtained for the practical examples shown in the paper.
{"title":"Application of genetic optimization algorithm to the crane problem in the shipbuilding industry","authors":"M. Arai, H. Nishihara","doi":"10.2534/JJASNAOE1968.2004.196_1","DOIUrl":"https://doi.org/10.2534/JJASNAOE1968.2004.196_1","url":null,"abstract":"In various contexts of the shipbuilding industry as well as in the marine transportation industry, the relocation of objects such as steel plates, containers, etc. by using cranes is a common task. In these operations, crane operators are faced with the problem of starting with a given distribution of objects and restacking them in order to achieve a desired distribution using the least possible effort or movement of the crane. This type of problem involves a practically infinite number of solutions, since the possible combinations of operational order are so numerous. Therefore, it is difficult for the operator to determine the optimal sequence from the candidate processes, and it also is difficult to present a general method that can solve this problem with high degrees of efficiency and reliability. As a result, in practical situations the crane operators on site usually decide the sequence according to their experience and intuition. However, sometimes the planning of the crane operation process is very troublesome and time consuming and is thought to be not necessarily suitable for human beings.In this study we apply a genetic algorithm (GA) that excels at finding solutions to combinatory problems. The sequence of a crane's operation is represented in string expression and with the merit of a population search (i.e., a simultaneous multi-point search) of the GA, excellent operations were efficiently obtained for the practical examples shown in the paper.","PeriodicalId":321056,"journal":{"name":"Journal of the Society of Naval Architects of Japan","volume":"615 ","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2004-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114092532","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}
Pub Date : 2004-06-01DOI: 10.2534/JJASNAOE1968.2004.195_33
Toru Sato, Takuro Yoshiakwa, S. Saito, Y. Tsuchiya
There is a discussion on the relation between Isahaya Dyke and the recent environmental change in Ariake Bay, which may devastate the Noni crop and exterminate shellfish. On the other hand, some say that the recent tidal decay in the outer sea is the main cause of the change in tidal current in Ariake Bay. Whatever the cause is, some ways to improve water quality are urgently needed even if they are local and temporal. We proposed a local engineering solution, a kind of seawater-quality enhancer, and simulated numerically and experimentally the diffusion of nutrient-rich water emitted by the apparatus. It is shown that 1-3% of the emitted water keeps to remain on the euphotic layer in Isahaya Inlet for a couple of weeks. This may imply the possibility of improvement of water quality by this engineering countermeasure.
{"title":"Prediction of Physical Effect of Seawater-Quality Enhancer Installed near Isahaya Inlet by Laboratory and Numerical Model Tests","authors":"Toru Sato, Takuro Yoshiakwa, S. Saito, Y. Tsuchiya","doi":"10.2534/JJASNAOE1968.2004.195_33","DOIUrl":"https://doi.org/10.2534/JJASNAOE1968.2004.195_33","url":null,"abstract":"There is a discussion on the relation between Isahaya Dyke and the recent environmental change in Ariake Bay, which may devastate the Noni crop and exterminate shellfish. On the other hand, some say that the recent tidal decay in the outer sea is the main cause of the change in tidal current in Ariake Bay. Whatever the cause is, some ways to improve water quality are urgently needed even if they are local and temporal. We proposed a local engineering solution, a kind of seawater-quality enhancer, and simulated numerically and experimentally the diffusion of nutrient-rich water emitted by the apparatus. It is shown that 1-3% of the emitted water keeps to remain on the euphotic layer in Isahaya Inlet for a couple of weeks. This may imply the possibility of improvement of water quality by this engineering countermeasure.","PeriodicalId":321056,"journal":{"name":"Journal of the Society of Naval Architects of Japan","volume":"123 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2004-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127234604","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}
Pub Date : 2004-06-01DOI: 10.2534/JJASNAOE1968.2004.195_283
K. Gotoh, Keitaro Konuma, M. Toyosada
Many fatigue damages in large welded built-up structures are found near a boxing fillet weld toe. These fatigue cracks usually initiate from the toe and propagate in the cross-section of wall thickness as surface cracks.Many attempts based on fracture mechanics for the improvement of fatigue life estimation are proposed, because current practical methods based on the S-N curves and the cumulative damage rules cannot estimate the accurate fatigue life under in-service structures. Whereas stress distributions along the fatigue crack path must be given in order to apply fracture mechanics methods for the precise fatigue life estimation, no stress distribuiton along the path is calculated because the shell type elements are used in finite element analyses in practical structural design stages.A simple estimation method of the stress distribution over the cross-section of a plate at weld toe, which corresponds to the supposed fatigue crack path in the case mentioned above, is proposed in this paper. The validity of this method is confirmed by comparing estimation results with ones by finite element analyses in which solid type elements are used.
{"title":"A Simple Estimation Method of the Normal Stress over the Cross-Section of a Plate at Weld Toe","authors":"K. Gotoh, Keitaro Konuma, M. Toyosada","doi":"10.2534/JJASNAOE1968.2004.195_283","DOIUrl":"https://doi.org/10.2534/JJASNAOE1968.2004.195_283","url":null,"abstract":"Many fatigue damages in large welded built-up structures are found near a boxing fillet weld toe. These fatigue cracks usually initiate from the toe and propagate in the cross-section of wall thickness as surface cracks.Many attempts based on fracture mechanics for the improvement of fatigue life estimation are proposed, because current practical methods based on the S-N curves and the cumulative damage rules cannot estimate the accurate fatigue life under in-service structures. Whereas stress distributions along the fatigue crack path must be given in order to apply fracture mechanics methods for the precise fatigue life estimation, no stress distribuiton along the path is calculated because the shell type elements are used in finite element analyses in practical structural design stages.A simple estimation method of the stress distribution over the cross-section of a plate at weld toe, which corresponds to the supposed fatigue crack path in the case mentioned above, is proposed in this paper. The validity of this method is confirmed by comparing estimation results with ones by finite element analyses in which solid type elements are used.","PeriodicalId":321056,"journal":{"name":"Journal of the Society of Naval Architects of Japan","volume":"71 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2004-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124847012","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}
Pub Date : 2004-06-01DOI: 10.2534/JJASNAOE1968.2004.195_15
H. Senga, Yong-pyo Hong, Takayuki Yoshimatsu, W. Koterayama
{"title":"A Fundamental Study on the Vortex Induced Vibration of a Long Flexible Riser","authors":"H. Senga, Yong-pyo Hong, Takayuki Yoshimatsu, W. Koterayama","doi":"10.2534/JJASNAOE1968.2004.195_15","DOIUrl":"https://doi.org/10.2534/JJASNAOE1968.2004.195_15","url":null,"abstract":"","PeriodicalId":321056,"journal":{"name":"Journal of the Society of Naval Architects of Japan","volume":"55 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2004-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127041755","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}
Pub Date : 2003-12-01DOI: 10.2534/JJASNAOE1968.2003.194_47
H. Iwashita
The aerodynamic properties of a canard-configuration WISES (Wing In Surface Effect Ship) flying over waves are predicted by applying the time-domain computation method based on the BEM, and the nonlinear characteristics of unsteady aerodynamic exciting forces acting on the WISES are studied through the comparison with experimental results and with linear computations reported in Part 1.Through the study it is confirmed that the presented time-domain computation considering the nonlinearity caused by the finite amplitude of waves can predict measured results more precisely compared with the linear method shown in Part 1, especially for the phase of exciting forces. The nonlinear phenomenon due to unsteady exciting forces remarkably appears in the center-of-pressure coefficient, but the amplitude of its fluctuation itself is small and not so serious for the stable flight of WISES above waves.
{"title":"A Study on the Aerodynamic Interaction of Wings and the Aerodynamic Properties of a Canard-Configuration WISES Flying over Still Water and Waves (Part 2)","authors":"H. Iwashita","doi":"10.2534/JJASNAOE1968.2003.194_47","DOIUrl":"https://doi.org/10.2534/JJASNAOE1968.2003.194_47","url":null,"abstract":"The aerodynamic properties of a canard-configuration WISES (Wing In Surface Effect Ship) flying over waves are predicted by applying the time-domain computation method based on the BEM, and the nonlinear characteristics of unsteady aerodynamic exciting forces acting on the WISES are studied through the comparison with experimental results and with linear computations reported in Part 1.Through the study it is confirmed that the presented time-domain computation considering the nonlinearity caused by the finite amplitude of waves can predict measured results more precisely compared with the linear method shown in Part 1, especially for the phase of exciting forces. The nonlinear phenomenon due to unsteady exciting forces remarkably appears in the center-of-pressure coefficient, but the amplitude of its fluctuation itself is small and not so serious for the stable flight of WISES above waves.","PeriodicalId":321056,"journal":{"name":"Journal of the Society of Naval Architects of Japan","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2003-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129375346","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}
Pub Date : 2003-12-01DOI: 10.2534/jjasnaoe1968.2003.194_271
信義 福地, Fukuchi Nobuyoshi, Shinoda Takeshi, 岳思 篠田, Shi Yuxiang, 雨湘 施, 耕平 田中, Tanaka Kohei, Hu Changhong, 長洪 胡
{"title":"A Study on the Ventilation System of Metallic Fume and the Working Environment in a Fabrication Shop : (Part 2) Changing Efficiency of Whole Ventilation","authors":"信義 福地, Fukuchi Nobuyoshi, Shinoda Takeshi, 岳思 篠田, Shi Yuxiang, 雨湘 施, 耕平 田中, Tanaka Kohei, Hu Changhong, 長洪 胡","doi":"10.2534/jjasnaoe1968.2003.194_271","DOIUrl":"https://doi.org/10.2534/jjasnaoe1968.2003.194_271","url":null,"abstract":"","PeriodicalId":321056,"journal":{"name":"Journal of the Society of Naval Architects of Japan","volume":"52 6","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2003-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121009900","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}
Pub Date : 2003-12-01DOI: 10.2534/JJASNAOE1968.2003.194_227
Y. Okumoto, Shinji Fujioka
{"title":"Application of Fuzzy Scheduling to Pipe Assembly Process","authors":"Y. Okumoto, Shinji Fujioka","doi":"10.2534/JJASNAOE1968.2003.194_227","DOIUrl":"https://doi.org/10.2534/JJASNAOE1968.2003.194_227","url":null,"abstract":"","PeriodicalId":321056,"journal":{"name":"Journal of the Society of Naval Architects of Japan","volume":"77 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2003-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131129033","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}
In the fire safety design for a ship, the engine room fire due to flammable oils is a veryy important issue and has received much attention in recent years. However, the nature of the engine room fire is still not well understood due to its extreme complexity of the physical and chemical mechanisms. A series researches have been carried out by the authors to investigate the engine room fire, and the emphasis of the present study is placed on the emission and the movement of the smoke during oil burning, which is very important phenomenon for a successful fire safe design such as setting up escape routes and installing fire detectors. In the present work, at first an oil burning experiment in a box-typed compartment, which is a simplified engine room fire model, is conducted on oxygen rich conditions to investigate the distinctive features of the smoke emission and the smoke movement for such type of engineer room fires. From the experiments, several types of quantitative relation between the oil burning rate and the smoke
{"title":"The Characteristic Analysis of Oil Pool Fire Phenomena for Fire Safety Design in Engine Room : (Part 2) A Kinetic Characteristic of Emitting Smoke during Oil Burning","authors":"Takao Jun, 潤 鷹尾, 信義 福地, Fukuchi Nobuyoshi, Hu Changhong, 長洪 胡","doi":"10.2534/jjasnaoe1968.2003.194_291","DOIUrl":"https://doi.org/10.2534/jjasnaoe1968.2003.194_291","url":null,"abstract":"In the fire safety design for a ship, the engine room fire due to flammable oils is a veryy important issue and has received much attention in recent years. However, the nature of the engine room fire is still not well understood due to its extreme complexity of the physical and chemical mechanisms. A series researches have been carried out by the authors to investigate the engine room fire, and the emphasis of the present study is placed on the emission and the movement of the smoke during oil burning, which is very important phenomenon for a successful fire safe design such as setting up escape routes and installing fire detectors. In the present work, at first an oil burning experiment in a box-typed compartment, which is a simplified engine room fire model, is conducted on oxygen rich conditions to investigate the distinctive features of the smoke emission and the smoke movement for such type of engineer room fires. From the experiments, several types of quantitative relation between the oil burning rate and the smoke","PeriodicalId":321056,"journal":{"name":"Journal of the Society of Naval Architects of Japan","volume":"15 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2003-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126847277","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}
Pub Date : 2003-06-01DOI: 10.2534/JJASNAOE1968.2003.193_65
T. Terasaki, K. Yamaguchi, T. Nomoto, T. Kitamura
{"title":"Study on Transverse Shrinkage and Angular Distortion Generated by Line Heating","authors":"T. Terasaki, K. Yamaguchi, T. Nomoto, T. Kitamura","doi":"10.2534/JJASNAOE1968.2003.193_65","DOIUrl":"https://doi.org/10.2534/JJASNAOE1968.2003.193_65","url":null,"abstract":"","PeriodicalId":321056,"journal":{"name":"Journal of the Society of Naval Architects of Japan","volume":"27 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2003-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114936249","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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