Application of equivalent analysis to analyzing anti-collision performance of aged ships
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摘要: 为了简化评估结构疲劳损伤后的抗碰撞性能,仿照结构蠕变分析中的等时应力-应变曲线的思想,提出了一种基于应变等效的等效分析法,并与通常的一般分析方法进行了比较。对比分析结果表明:等效分析法与通常的一般分析方法模拟的结构最大抗破坏作用力几乎相同,并且两者模拟的结构破坏能相对误差较小。这验证了等效分析法的有效性,说明等效分析法可用于船舶全寿命期内抗碰撞性能的快速评估。Abstract: In order to simplify the evaluation of the anti-collision performance after structural fatigue damage, an equivalent stress-strain curve method based on strain equivalence was proposed in the same way as the isochronous stress-strain curve in structural creep analysis. And compared with the general analysis, the results of comparative analysis show that the maximum damage reaction force from the equivalence analysis method is almost the same as that from the general analysis method, and the relative error of the structural failure energy simulated by the two methods is relatively small. It validates the effectiveness of the equivalence analysis method. And the equivalence analysis method is more friendly to model and evaluate rapidly the anti-collision performance over the entire life of a ship.
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Key words:
- fatigue /
- damage /
- collision /
- strain equivalence /
- equivalent stress-strain
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表 1 疲劳损伤分析及碰撞分析工况
Table 1. The load cases of fatigue damage analysis and collision analysis
工况 疲劳工程应力幅/MPa 循环次数 极限循环次数 碰撞冲击速度/(m·s–1) 1 397.5 100 1 680 0.5 2 496.9 50 146 3 80 4 596.2 10 18 5 15 表 2 不同工况下一般分析法与等效分析法结果对比
Table 2. Comparison of the general simulation and the equivalent simulation in the different load cases
工况 破坏能/J 一般分析方法与等效分析法相对误差/% 不考虑损伤的结构 考虑损伤的一般分析方法 考虑损伤的等效分析法 1 63 648 62 605 61 338 2.02 2 57 490 60 049 4.45 3 56 177 56 260 0.14 4 56 830 57 900 1.88 5 56 984 54 234 4.82 -
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