| Author Name | Affiliation | | Er Zhang | Department of Naval Architecture Engineering,Naval University of Engineering, Wuhan 430033, China | | Fan Wu | Department of Naval Architecture Engineering,Naval University of Engineering, Wuhan 430033, China | | Kairen Mao | Department of Naval Architecture Engineering,Naval University of Engineering, Wuhan 430033, China | | Chunzheng Liu | Department of Naval Architecture Engineering,Naval University of Engineering, Wuhan 430033, China |
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| Abstract: |
| As a new joint structure, the impact of initial imperfection to stress of Concave cone-toroid-cylinder combined shell was analyzed. Firstly the location and shape of combined shell's initial imperfection caused by welding was studied. Secondly dominated stress was chosen after comparing varioustypical stress. Then it was analyzed that the influence of imperfection to dominated stress via changing the shape of frame's deflection and shell's concave-convex. At last the strengthening case for combined shell with imperfection was pointed out. The conclusions are: (1) Stress of frame 9 is more sensitive to initial imperfection than circumferential stress of toroidmidsurface, which is a new concern; (2)To strength the frames in the sides of toroid not only can decrease the stress of frame, but also can reduce the circumference stress of toroid's midsurface. |
| Key words: concave cone-toroid-cylinder combined shell initial imperfection stress strengthening scenario |
| DOI：10.11916/j.issn.1005-9113.15245 |
| Clc Number:U663 |
| Fund: |
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| Descriptions in Chinese: |
| 含局部初始缺陷的凹锥-环-柱结合壳加强方法研究 张二；吴梵；毛开仁；刘春正 （海军工程大学舰船工程系， 武汉 430033） 创新点说明： 本文的创新点主要有以下几个方面，1）本文通过ANSYS，建立了含初始几何缺陷的有限元模型；2）通过应力敏感度的分析，环壳两端肋骨应力对初始几何缺陷敏感度大于环壳中面周向应力。 研究目的： 本文针对凹锥-环-柱结合壳这一新型连接结构，分析初始几何缺陷对其应力水平的影响，研究加强方法。 研究方法： 采用有限元分析方法，通过建立含不同初始几何缺陷的有限元计算模型，选取出典型的初始几何缺陷形态。研究不同形态的初始几何缺陷对凹锥-环-柱结合壳应力的影响规律，进而确定含初始几何缺陷的凹锥-环-柱结合壳的加强方案。 结果： 本文主要引入了四种初始几何缺陷形态，其中（1）对于四个不同形态的初始几何缺陷，当初始缺陷幅值倍数△=0.5时，环壳中面周向应力依然小于许用应力0.85σs，而肋骨应力均已超过许用应力0.6σs，这表明环壳两端肋骨应力较环壳中面周向应力对初始缺陷更加敏感。（2）当四个工况的初始几何缺陷幅值均达到允许值上限时，环壳中面周向应力以及肋骨应力均超过许用应力，呈危险状态。其中，当初始缺陷形态为工况一时，环壳中面周向应力达到最大，超出许用应力2.2%；当初始缺陷形态为工况二时，#9肋骨应力达到最大，超出许用应力11.9%。（3）通过加强#8、#9肋骨，可有效降低肋骨应力，使其满足许用应力的要求；同时对环壳中面周向应力也起到了一定的改善作用。（4）通过增加环壳厚度，可以大幅降低环壳中面周向应力，这与文献的结论一致；但环壳厚度的增加不能有效改善肋骨应力，通过方案二的加强，肋骨应力依然不满足许用应力的要求。 结论： （1）环壳段壳板中面周向应力及环壳段两端肋骨应力较大，成为凹锥-环-柱结合壳设计时的控制应力，需重点关注。（2）环壳两端肋骨应力对初始几何缺陷敏感度大于环壳中面周向应力。环壳段两端肋骨在设计时适当加强，以提高结构的安全性。 关键词：凹锥-环-柱结合壳；初始几何缺陷；应力；加强方案 |
