无加筋平板极限强度的简化解析法与规范公式的比较

无加筋板是船舶结构的主要构件之一，船舶结构强度校核的一项重要内容就是校核各平板单元是否具备足够的强度储备。最近几年，作者们采用弹性大挠度理论和刚塑性分析相结合的简化解析方法，曾给出了板和加筋板格在联合载荷作用下的极限强度计算公式，并与部分实验值相比，吻合较好，但没有与目前船级社所采用的规范计算公式作过比较。现作这一比较工作，也包括与有限元分析的比较；同时对以前所开发的简化解析法又作了进一步的改进，文章报道这一改进结果。最后，采用上述三种方法，对影响平板极限强度的几个主要参数进行了研究，结果表明，简化解析法与规范计算公式吻合较好。

A Comparison between Simplified Analytical Method and Design Formulas for Ultimate Strength of Unstiffened Plates

Unstiffened plate is one of the most important components of ship structures. To verify unstiffened plate ultimate strength is an important task for ship strength verification. In recent couple of years, authors have developed a Simplified Analytical Method for the prediction of ultimate strength of unstiffened plates and stiffened panels based on the combination of elastic large deflection analysis and rigid plastic analysis. But the elastic small deflection theory is applied to calculate the work done by lateral pressure. In this paper, the Simplified Analytical Method is developed using elastic large deflection theory to calculate the work done by lateral pressure. By comparison with limited experimental data, the results show more reasonable agreement. The Simplified Analytical Method has not been compared with the design equations used by ship classification societies before. The main purpose of this paper is to carry out such a comparison including comparing with finite element analyses. The influences of various factors affecting the ultimate strength of unstiffened plates, such as welding residual stress, transverse stress, lateral pressure, have also been studied using the three approaches. It is found that design formulas adopted by ship classification societies generally agree with theoretical analyses and finite element analyses, but tend to be silightly conservative than the analytical results.