船体薄壁梁的二次剪流和二次扭矩

将船体作为阶梯薄壁梁,用薄壁梁的约束扭转理论进行扭转强度分析的方法,是目前国内外造船界普遍使用的方法。 本文讨论了翘曲约束引起的二次剪流的计算问题,提出了一个适于用电子计算机计算的规格化的方法,并简单介绍了依据此方法编制的计算程序。 本文还通过对二次剪流直接积分,证明了二次扭矩和双力矩之间的微分关系式在具有闭室的薄壁梁的情形下同样成立。

SECONDARY SHEAR FLOW AND TORSIONAL MOMENT IN THIN-WALLED SHIP HULL GIRDER

The method for torsional analysis of ship hull as a stepped thin-walled beam using the restrained torsion theory has been applied widely in the field of naval architecture.The calculation of the secondary shear flow due to warping restraint is discussed. A method with systematic manner for computer programming is presented. Also a computer program based on this method is briefly introduced.Based on the classical torsion theory, secondary torsional moment and bimoment have following differential relation, dB/dz=M_w It is easy to prove this relation for pure open sections. But when the cross-section has closed cells, some difficulties will arise. An approach to prove the above mentioned relation also suiting to the sections with clossed cells is presented. It is shown that the above-mentioned relation is generally valid.