Research on buckling collapse behavior and ultimate strength of stiffened plating in compression

本课题研究的主要内容和成果如下：(1)在轴向压杆作用下加筋板的破坏分析中，考虑了加筋板的建模问题，发现最有效的建模方法是按板模拟腹板，按梁柱模拟翼缘。(2)加筋板与板材的倾角对加筋板屈曲破坏行为的影响。将新的ISUM板元与梁柱单元相结合，非常准确地模拟了连续加筋板在双向荷载和压力荷载共同作用下的倒塌行为。(4)弯曲加筋板的屈曲/塑性倒塌行为研究发现，…具有弹性局部屈曲的特点。更多的GTH随着弯曲角度的增加而线性增加。另一方面，实际船体结构中的曲线板发生塑性屈曲，极限抗压强度与屈服强度接近。(5)加劲肋残余应力对加筋板屈曲破坏行为的影响--轧制和焊接T型加筋板腹板和翼缘的残余应力符号。但这种差异对加筋板的极限抗压强度影响不大。(6)考虑加筋板脱扣对加筋板破坏行为的影响研究发现，由于整体弯曲，加筋板在受压侧的加筋板腹板发生脱扣。(7)铝加筋板的屈曲行为和强度焊接残余应力提高了铝加筋板的屈曲/极限强度。另一方面，热影响区材料的软化降低了铝加筋板的极限抗压强度。较少

The items and results of research issues which have been studied in the present research project are as follows.(1)Consideration on modelling of stiffeners in the collapse analysis of stiffened panel under axial thrustIt was found that most effective modeling is to model the web by plate and the flange by beam-column.(2)Influence of inclination angle of stiffeners to plating on buckling collapse behavior of stiffened platesIt was found that inclination angle does not affect the local buckling strength, whereas it affects the capacity beyond the ultimate strength as well as the overall buckling strength.(3)Application of ISUM to collapse analysis of stiffened plates subjected to combined loadingCombining new ISUM plate element and beam-column element, collapse behavior of continuous stiffened plates under combined bi-axial and pressure loading was simulated very accurately.(4)Buckling/plastic collapse behavior of curved stiffened platesIt has been found that elastic local buckling stren … More gth increases linearly with the increase in curved angle. On the other hand, the curved plates in actual ship structure undergoes plastc buckling, and the ultimate compressive strength is nearly equal to the yielding strength.(5)Influence of residual stress in stiffeners on buckling collapse behavior of stiffened platesThe sign of the residual stress in web and flange opposite in rolled and welded T-type stiffeners. However, this difference affect a little on the ultimate compressive strength of stiffened plate.(6)Consideration on influence of stiffener tripping on collapse behavior of stiffened platesIt was found that tripping takes place at the stiffener web in the compression side of bending resulting from over-all bending. The condition for the occerrence of tripping is left unknown.(7)Buckling collaose behavior and strength of alminium stiffened platesThe welding residual stress increases the buckling/ultimate strength of alminium stiffened plate when the stiffened plate is fabricated by connecting rolled stiffened plates by butt-welding. On the other hand, softening of the material in heat affected zone reduce the ultimate compressive strength of alminium stiffened plates. Less