【作者】 余友谊；

【导师】 孙海虹； 张少雄；

【作者基本信息】 武汉理工大学 ， 结构工程， 2004， 硕士

【摘要】 加筋板是船舶和海洋结构物中的基本结构构件。由于制作简单且有良好的强度重量比，加筋板也广泛应用于制造陆基结构物如箱梁和板梁桥等。由于船体梁的总体破坏通常由甲板、底板或者舷侧加筋板的屈曲或塑性破坏控制，因此在船舶结构设计中准确地计算甲板、底板或舷侧加筋板的极限强度就显得尤为重要。 随着高强度钢的广泛应用，板格屈曲大部分发生在弹性范围内，在后屈曲阶段当板格最大面内压缩应力处的等效应力达到屈服极限时，板格迅速卸载，此时板格达到极限强度。本文主要研究了各种缺陷和损伤对加筋板抗压极限强度的影响。由于准确的确定加筋板中带板的有效宽度十分重要，因此本文首先对加筋板中板格有效宽度进行了理论分析，在此基础上引入各种缺陷和损伤形式进行了大量的数值计算，定量研究了各种缺陷和损伤对板格抗压极限强度的折减。 本文考虑板中可能存在孔洞、腐蚀、裂缝、局部撞损和初始焊接变形或残余应力等损伤和初始缺陷，对不同的损伤形式用有限元程序(ANSYS)进行大量的计算，通过曲线拟合的方法引入折减系数对完好板格的有效宽度进行修正。在进行受损加筋板格极限强度计算时，按梁柱法采用修正的Perry-Robertson方程进行计算，其中有效带板的宽度取板格折减后的有效宽度。这样得到了一个含有各个参数的显式的极限强度公式。通过本文的研究工作，得出了以下几点结论： 1．联立弹性大变形法和刚塑性法求解板格极限强度，得到了一个简单的显式表达的完好板格极限强度公式，使得板格极限强度预报有了理论依据。 2．将板格的各种缺陷和损伤形式参数化，通过大量数值计算拟合出受损板格极限强度折减系数的以损伤参数为变量的显式表达示，用折减系数对完好板格极限强度进行折减得到受损板格极限强度公式。 3．在受损加筋板极限强度计算中，对有损伤的带板有效宽度取受损板格的有效宽度进行计算。 4．针对腐蚀这一损伤形式，应用现有统计资料对加筋板极限强度作了可靠性分析。更多还原

【Abstract】 Stiffened steel panels are the basic strength members in ship and offshore structures. Due to their simplicity in fabrication and excellent strength to weight ratio, stiffened steel panels are also widely used for construction of land based structures such as box girder and plate girder bridges. Since the overall failure of a ship hull is normally governed by buckling and plastic collapse of the deck, bottom or sometimes the side shell stiffened panels, it is of crucial importance to accurately calculate the ultimate strength of stiffened panels in deck, bottom and side shell for more advanced structural design of ship structures.The buckling of a plate mostly occurs in elastic regime with high strength steel adopted widely, and the plate reaches ultimate strength due to losing capacity when equivalent stress where maximal in-plane compressive stress appears arrives at yield in post-buckling phase. The elastic large deflection solution and rigid plastic solution are combined to achieve theoretical formula of ultimate compressive strength of a plate in the present paper, which agrees well with the result by the finite element calculation (ANSYS) and existing experiential expressions.The reduction factors derived from curve fitting based on calculation results by the finite element program (ANSYS) considering all kinds of damages such as cutouts, corrosion, cracks, denting, initial deflection and residual stress are introduced to modify the effective width of perfect panel in the present paper. The modified Perry-Robertson equation is applied to calculate ultimate compressive strength of damaged stiffened panels founded on so-called beam-column method, and the width of effective plate adopts above reduced effective width of a damaged plate. Several conclusions are achieved in the present research as follow:1. An explicit formula of ultimate strength is achieved according as combination of elastic large deflection method and rigid plastic method for perfect plates.2. The explicit formulae with damage parameters as variable of reduction factors for ultimate strength of damaged plates are achieved by curve fitting based on a mass of numerical computation for parametric imperfection and damage of plates.3. The effective width of damaged attached plates adopt the effective width of damaged plates in ultimate strength computation of damaged stiffened panels.4. The reliability of ultimate strength of corroded stiffened panels is analyzed.更多还原