摘要虽然 IACS 规范在船舶工程界得到了广泛的应用，但其中对于船体梁极限强度 计算中对于硬角单元的界限划分十分模糊，因此在实际应用中很多工程技术人员对于 圆弧结构是否应该划分为硬角单元存在疑问，同时在规范中亦没有明确地说明圆弧结 构是否应该划分为硬角单元，以及什么样的圆弧才能划分为硬角单元等，基于以上各 种实际问题，本文对硬角单元的评判标准进行研究，以便能够解决硬角单元的划分问 题。79120

本文根据 IACS 规范，先是验证用有限元软件进行屈曲分析的可行性和精度，然 后运用 ANSYS 软件分析由各种单元组成的普通梁，各种箱型梁的极限强度，并且讨 论硬角单元对极限强度的影响，然后根据仿真所求出来的结果来分析非硬角单元到硬 角单元箱型梁和船体梁极限强度的变化。

本论文研究的具体内容为：（1）用 ANSYS 建模求解，然后将求出的结果与理论 值进行比较，最终得出用 ANSYS 软件进行屈曲分析是可行的，精度较高；（2）通过 改变弧长及曲率来研究平板、L 形板及圆弧壳单元的临界屈曲强度，将他们的结果进 行比较，发现弧长以及曲率对极限强度的影响较大；（3）通过改变箱型梁四个角处的 倒角，将所得的结果与没有倒角的箱型梁进行对比，发现圆弧形结构设置加强筋时应 该设为硬角单元。

毕业论文关键词： IACS规范，硬角单元，圆弧结构，极限强度

Abstract Although IACS rules have been widely used in the field of ship engineering, it is not clear to the limit of the hard angle unit in the ultimate strength of the hull girder。 Therefore, in practical applications, many engineering and technical personnel has problem that if the circular structure should be pided into the hard angle。 At the same time, there is no clear description of the arc structure should be pided into hard angle unit。 And what kind of arc can be pided into hard angle unit, etc。 Based on the above all kinds of practical problems, the evaluation criteria of hard angle unit are studied in this paper, In order to solve the problem of the pision of hard angle unit。

In this paper, according to the IACS rules, the feasibility and accuracy of buckling analysis are verified by finite element software firstly。 Then the ANSYS software is used to analyze the ultimate strength of the ordinary beams and box girders, which are composed of various units, and discuss the influence of hard angle unit on the ultimate strength。 Then, according to the results obtained from the simulation, the change of the ultimate strength of the box girder and the hull girder of the hard angle unit is analyzed。

The specific contents of this dissertation are as follows：(1) The results are   obtained

by ANSYS modeling, then the calculated results are compared with the theoretical values。 Finally, it is feasible to use ANSYS software to analyze the buckling, and the accuracy is higher。 (2) By changing the length and curvature of the arc length, the critical buckling

strength of flat plate，L plate and circular arc shell element is studied。 By comparing  their

results, it is found that the arc length and the curvature have great influence on the ultimate strength。 (3) By changing the box girder four corner chamfer, The chamfered box beam and no chamfer of the box beam of the calculated results are compared。 It is found that the hard angle unit should be set when the reinforced bars are arranged on the circular arc structure。

Keywords: IACS rules； Hard Angle unit；Arc structure; Ultimate strength

目录

第一章 绪论 1

1。1 选题的目的和意义