A Design Chain for Distributed Electric Propulsion with Increased Fidelity Structural Strength Assessment and Mass Estimation

2022 ◽  
Author(s):  
Alp Emre Öngüt ◽  
Vincenzo Cusati ◽  
Vittorio Memmolo ◽  
Fabrizio Nicolosi ◽  
Francesco Orefice ◽  
...  
Keyword(s):  
Electric Propulsion ◽  
Structural Strength ◽  
Strength Assessment ◽  
Mass Estimation ◽  
Design Chain

The Research of Statistic Prediction for Wave Loads Based on Three Dimensional Method

2013 ◽  
Author(s):  
Yihan Zhang ◽  
Huilong Ren ◽  
Hui Li ◽  
Xiaoyu Li
Keyword(s):  
Structural Strength ◽  
Wave Spectrum ◽  
Three Dimensional ◽  
Frequency Interval ◽  
Wave Loads ◽  
Short Term ◽  
Empirical Formulas ◽  
Strength Assessment ◽  
Term Prediction

The exact prediction of wave loads for ship or other marine structure is the key to its design and the assessment of structural strength, reliability and security. The short-term and long-term prediction of wave loads are always used in direct calculation for structural strength, fatigue strength assessment and so on based on spectral analysis method. In this paper, the numerical calculation method for statistic prediction is discussed firstly, including the Weibull distribution fitted method and the stack method. Further more, it is necessary to find a quick solution in order to improve the efficiency to compute the nonlinear equation in the second method. Then, some main factors that may influence the long-term or short-term prediction are discussed, such as wave spectrum, wave scatter diagram, incident wave angle interval and frequency interval. Finally, the wave loads prediction for a series of typical bulk carriers and oil tankers are calculated by the uniform predict method discussed above base on three dimensional wave loads calculation theory. The results showed that the method used in this paper can predict the statistic value of wave loads induced by irregular incident waves conveniently and efficiently. A rule to choose a series of uniform factors is confirmed for statistic prediction and some empirical formulas for long-term value of wave bending moment are concluded which are very useful in marine engineering.

scholarly journals A Study on Structural Strength Assessment of Polyethylene Boat

2013 ◽  
Vol 14 (3) ◽  
pp. 1045-1053 ◽  
Author(s):  
Seok-Swoo Cho ◽  
Won-Min Kwak ◽  
Bum-Sik Ham ◽  
Young-Chul Jo
Keyword(s):  
Structural Strength ◽  
Strength Assessment

Global Strength Assessment of Trimaran Structure

2012 ◽  
Vol 538-541 ◽  
pp. 2860-2863 ◽  
Author(s):  
Khurram Shehzad ◽  
Hui Long Ren ◽  
Chun Bo Zhen ◽  
Asifa Khurram
Keyword(s):  
Structural Strength ◽  
Direct Calculation ◽  
Fe Analysis ◽  
Strength Analysis ◽  
Stress Concentrations ◽  
Strength Assessment ◽  
Analysis Technique ◽  
Current Design ◽  
Design Loads ◽  
Global Strength

This paper presents structural strength assessment of trimaran by global FE-analysis. Global strength analysis using the finite-element method is a powerful tool extensively used to design well-balanced and reliable sea going vessels. This analysis technique is particularly recommended in unconventional and new ship designs. Lloyd’s Register rules (LR Rules) for classification of trimaran are used to compute design loads and load cases. Global FE analysis is performed as per direct calculation procedure of LR Rules. Maximum stress concentration locations or hot spots corresponding to each load case are identified. The stresses induced in trimaran structure for all load cases are less than the maximum allowable stress. Furthermore, some modifications in current design are suggested to reduce the stress concentrations and hence to improve the structural strength.

Design of Ship Weight Reduction Based on Reliability Analysis of Longitudinal Bending Strength

2015 ◽  
Author(s):  
Huilong Ren ◽  
Qingyue Zhang ◽  
Xueyun Jiang ◽  
Yumeng Hu
Keyword(s):  
Reliability Analysis ◽  
Optimization Model ◽  
Bending Strength ◽  
Structural Strength ◽  
Safety Margin ◽  
General Characteristic ◽  
Wave Loads ◽  
Strength Assessment ◽  
Component Size ◽  
Longitudinal Bending

As the focus of the structural design, the form and dimension of components in the mid-ship section reflect the general characteristic of the whole ship, thus playing a significant role in the weight and structural strength of the whole ship. However, traditional deterministic methods of structural strength assessment will bring excessive safety margin, which will lead to excessive weight of ship structure. In this paper, the optimization model was built in view of ship longitudinal bending strength reliability analysis by MATLAB software. With the information of wave loads forecast and that of the section bending strength, the failure probability was obtained. Objective function was the weight of mid-ship section, and optimization variables were the size of sectional components, and the constraints were reliability index and component size limits were required by relevant norms. Combined with the optimization model, genetic algorithm toolbox integrated in MATLAB was applied to study mid-ship section optimization. Results of the examples showed that in the case that the limiting conditions were satisfied, the weight of mid-ship section was reduced to a certain extent, which meant that this method was effective for mid-ship section optimization.

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