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A Study on Strength Characteristics, Weldability and Corrosion Resistance of Duplex Stainless Clad Steel Plate for Chemical Tanker Construction
Get PDFDuplex stainless (SUS329J3L) clad steel plate is newly developed and commercialized in 2016. The fundamental problem to be solved for the utilization of SUS329J3L clad steel plate in chemical tanker construction is to secure the strength and reliability on the bonded interface of SUS329J3L clad steel plate. In this study, the fracture toughness, fatigue crack propagation characteristics of the bonded interface of SUS329J3L clad steel plate and fatigue strength of the welded joints of the clad steel plates were investigated and also the weldability and corrosion resistance of the clad steel plate were evaluated. The results can be summarized as follows.
① From the results of fracture toughness tests using cruciform welded joint specimens and CT type specimens of the bonded interface of SUS329J3L clad steel plate and fatigue crack propagation tests using CT type and CCT type specimens of that, we concluded that duplex stainless (SUS329J3L) clad steel plate can be sufficiently utilized in chemical tanker construction.
② The fatigue strength of cargo tank structure of chemical tanker using a combination of SUS329J3L clad steel plates and SUS329J3L solid steel plates is equal or superior to that of cargo tank structure using a conventional combination of austenitic stainless (SUS316L) clad steel plates and SUS316LN solid steel plates.
③ Through the evaluation of the weldability of tested clad steel plates, we clarified the fact that SUS329J3L clad steel plates are equal or superior to SUS316L’s in the various strength characteristics and weldability.
④ In terms of the corrosion resistance, it was clarified that the cladding material of SUS329J3L steel plate is equal or superior to that of SUS316L steel plate.departmental bulletin pape
Improvement of Navigation Optimization Technologies in ships
Get PDFVarious endeavors for environmental protection are continuing in many fields of industry.
The author has approached this problem by developing new technologies for minimizing fuel oil consumption to reduce exhaust gases over the navigation routes in marine transportation.
In the preceeding studies, the relationship between speed drop caused by waves and wave resistance was made clear quantitatively in the case that the work of thrust to navigate straight over a definite distance is the same between calm sea and wave conditions. Moreover the amount of fuel oil consumption was analyzed to distribute the main engine outputs optimally on the basis of this relationship.
In this paper, the above relationship was formulated more strictly in the case that ships navigate under wave conditions with the same main engine output as under calm sea conditions to analyze fuel oil consumption , and the decision equations for optimal steering and distribution of main engine outputs are modified.
Finally, the effectiveness of the results of this study is evaluated in comparison with preceeding studies through several cases of numerical simulation.departmental bulletin pape
Study on Energy Management for Islanded Operation Mode of Medical Facility Power Grid
Get PDF長崎総合科学大学博士（工学）2018doctoral thesi
Study on Proper Arrangement of Damping Material for a L-shaped Plate with Coupling Loss Factor as an Objective Function
Get PDFA structural optimization method of subsystems to realize desired SEA parameters was proposed by the authors in the past studies. This method is based on a combination of SEA and FEM calculation, calculating repeatedly until satisfying the value of objective functions under arbitrary constraints. As a result of applying the proposed method to a simple structure consisting of two flat plates connected in an L shaped configuration, the design variable is taken as the thickness of the FEM element, a subsystem structure with the desired value of the CLF or power flow between subsystems for the one frequency band or multi frequency bands were constructed. However, it is difficult to apply the optimal results to real machine structure because of setting the thickness of the FEM element as the design variable. In this paper, the method is also validated through numerical analyses, using a finite element method, of an L shaped plate, the subsystem is grouped into a plural elements, and the each grouped element is set as a design variable, which should take a discrete value, the total mass is taken as a constraint function in order to minimize CLF12 at one frequency band. As a result, in comparison with experimental data, numerical analysis results are qualitatively accurate.departmental bulletin pape
A Study on Prediction of Vibration and Sound Pressure Response for SEA Considering Variation of Vibration Input Power
Get PDFThe authors developed the structural design process on the basis of experimental SEA for reducing structure-borne sound. However, it was difficult to predict the sound pressure accurately in order not to predict the variation of vibration input power by structural modification. There are four steps in the process, at the third steps, the process identifies the internal loss factors (ILFs) or the coupling loss factors (CLFs) which should be changed in order to reduce the noise radiated from the machinery using sensitivity analysis to the squared sound pressure at the evaluation point. The sensitivity analysis is based on the perturbation method, the squared sound pressure or the vibration energy are evaluated regarding the variation of respective loss factors and input power. For two SEA models are used with and without predicted vibration input power by structural modification, parameter study are implemented by analytical SEA. As a result, it can be seen that sound energy values for the SEA model without using the predicted vibration input power for structural modification by a partial thickness change are overestimated for a flat plate. The same phenomenon for L shaped plate was also confirmed by the experimental test.departmental bulletin pape
Analysis of the Christian Town of Omura in the 16th and 17th century (1)
Get PDFSumitada Omura is known as the first Japanese Christian daimyo in the opening of Yokoseura port, as well as the opening of Nagasaki port and the Tensho Boys Delegation to Europe in the late 16th century. However, the important Christian town of Omura is hardly known in history. This study looks at the first church made by Omura,language study college, Sakaguchi and relations with Omura,and the church of the Kushima castle. By the main subject, I considered the formation and decline of these Omura Christian facilities based on new knowledge.departmental bulletin pape