Authors: Joo Shin Park, Yun Young Kim, Tetsuya Yao
Abstract: The optimum design for bow structure of high tensile steel yacht belongs to the nonlinear
constrained optimization problem. The determination of scantlings for the bow structure is a very
important matter out of whole structural design process of a yacht. The optimum design results are
produced with the use of Real-coded Micro-Genetic Algorithm including evaluation LR small craft
guideline, so that they can satisfy the allowable stress criterion. In this study, the minimum weight
design of bow structure on the HTS yacht was carried out based on the finite element analysis. An
analysis model is a bow structure of HTS yacht with structural scantling derived from the minimum
weight optimization. The weight of bow structure and the main dimensions of structural members
are chosen as an objective function and design variable, respectively. Optimization results were
compared with a pre-existing design. From the FE analysis results, bow structure with high tensile
steel (AH40) designed by using RμGA has a volume efficiency of 19% than the design of the actual
mild yacht.
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Authors: Yehia Abdel Nasser, Aly Aliraqi, Bader El Din Ali
Abstract: Structural design of ships against collision requires prediction of the extent of damage to stiffened plates subjected to impact. In ship structures, stiffened plates are furnished with vertical or horizontal stiffeners to sustain conventional loads such as shearing, bending and local buckling. The consideration of collision in ship structural design is especially important for tankers where accidents may cause serious environmental pollution. In predicting the extent of collision damage, FE modeling of stiffened plates using ABAQUS software is applied to demonstrate different collision scenario. Typical stiffened plates of tankers in service with different configurations of stiffeners are used to examine absorbed energy in each case. The aim of this paper is to examine the stiffener shape that absorbs more deformation energy.
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Authors: Ya Nan Huang, Da Lu Liu, Feng Sheng Sun, Da Yong Zhang, Dong Lu
Abstract: In this paper, taking a 7000 TEU container ship as an example, research on optimization design of mold lines of bulbous bow for container ships is carried out. Firstly, geometric parameters of bulbous bow are selected to be as variables to construct 7 computing molds, then CFD methods are employed to calculate ship resistance and parameters of wave field generated by ship moving, as well as Michell integration is used to determine the coefficient of wave-making resistance. Minimization of resistance is taken as the aim function to obtain the optimum geometric parameters of mold lines at bow. The results of mold testing express that the mold lines of bulbous bow for container vessel optimized by above methods are credible and valuable for engineering practice.
417
Authors: Xiao Liang Yue, Feng Feng, Jun Chen
Abstract: The hyperelastic-viscoelastic model was applied on HTPB propellant to simulate the large strain problem during tensile test. The feasibility of using micro bow-shaped transducer to measure the large strain of HTPB propellant was discussed. The ABAQUS package was used to simulate the HTPB propellant tensile test with different sizes of micro bow-shaped transducer. The effect of micro bow-shaped transducer size on large strain measuring was concluded, and the foundation of determining bow-shaped transducer size was given. The strain transfer relational expression for a given size was obtained. It will be reference for solving the large strain measuring of HTPB propellant in complex working condition.
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Authors: Buddhika Abeyrathna, Bernard Rolfe, Peter D. Hodgson, Matthias Weiss
Abstract: V-sections were roll formed from two grades of steel, and the strain on the top and bottom of the strip near the edge was measured using electrical resistance strain gauges. The channels were bent to a radius of 2 and 15 mm along the centerline. The steel strips were of mild and dual phase steel of yield strength 367 MPa and 597 MPa respectively. The longitudinal bow was measured using a 3-dimensional scanning system. The strain measurements were analysed to determine bending and mid-surface strains at the edge during forming.
The peak longitudinal edge strain increased with material yield strength for both profile radii. For the 15 mm radius, the bow was larger in the dual phase steel than in the mild steel. For the 2 mm profile radius, the bow was smaller compared with the 15 mm profile radius and it was similar for both steels. It was observed that the difference between the peak longitudinal edge strain and yield strength to Youngs modulus ratio of the material is an important factor in determining longitudinal bow.
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