921A钢板架欧拉应力计算的标准适用性研究

Applicability Study of Euler Critical Stress Evaluation for 921A Steel Grillage to Ship Standard

当欧拉应力超过材料的比例极限时,可用欧拉应力修正曲线计算板架结构的稳定性。目前,国家军用标准适用于低碳钢和低合金钢,未给出材料屈服强度大于441 MPa高强度钢的欧拉应力修正曲线。因此,设计不同柔度的压杆试件模拟纵向带板骨架结构的整体屈曲变形,开展简支约束下的轴压试验,并与理论公式和有限元计算结果进行对比,确定高强度钢板架的临界应力曲线,获取欧拉应力修正曲线的经验公式。通过研究发现,现有标准中的欧拉应力修正曲线高估了板架的临界应力,论文提出的新修正曲线可较准确地计算高强度钢板架的临界应力,从而完善舰船纵向骨架结构的设计与稳定性校核方法。

The modified curves of Euler stress could be utilized to assess the stability of grillage structures when the Euler stress exceeds the proportional stress limit of the steel. At present, the national military standard gives the modified curves of Euler stress for low-carbon steel and low-alloy steel, but not for high-strength steel with yielding stress larger than 441 MPa. Column samples with different slenderness were designed to simulate global beam-column buckling deformation of longitudinal grillage structures with attached plates. Compression tests under simply supported constraints were performed to conduct comparative research with theoretical formulae and finite element analyses, which could confirm the critical stress curve with high-strength steel grillage and derive empirical formulae of the modified curves of Euler stress. Current modified curves of Euler stress with low-carbon steel and low-alley steel in the national military standard would overestimate the critical stress of the high-strength steel grillage, which could be properly calculated by the proposed modification curves of Euler stress so as to improve the structural design and its stability verification.