【作者】 吴香国；

【导师】 安伟光；

【作者基本信息】 哈尔滨工程大学 ， 固体力学， 2006， 博士

【摘要】 初始几何缺陷是实际结构最主要的缺陷之一，初始缺陷结构的屈曲概率研究是结构可靠度理论在现代结构稳定性理论领域的重要应用。基于结构可靠度的初始缺陷结构屈曲容许荷载能够充分考虑结构的客观缺陷和参量的随机特性，更符合工程实际，因此，开展基于结构可靠度的缺陷结构屈曲安全设计具有一定理论意义和应用前景。 本文开展了初始缺陷对结构屈曲可靠度的影响研究。在大量文献研究的基础上，提出了基于载荷对位移最大变化速率点PBP(Pseudo BifurcatePoint)的安全屈曲载荷设计的方法，将传统的稳定失稳和不稳定失稳统一为广义分支失稳。基于梁柱屈曲理论和验算点法，建立了初始偏心和初始挠曲缺陷结构的屈曲安全余量，建立了集中载荷、均布载荷和端部弯矩载荷等组合载荷作用下的不完整梁柱结构的屈曲安全余量，分析了初始缺陷对结构屈曲可靠度的影响。研究了具有初始几何缺陷的刚架结构屈曲问题，通过数值计算结果，分析了组合载荷的临界值域分布，推导并建立了以缺陷无量纲幅值为变量的结构BCPL(The Biggest Curvature Point Load)屈曲安全余量方程。 利用傅立叶变换，推导了局部缺陷薄壁圆柱壳结构的屈曲载荷的解析解，建立了局部对称缺陷圆柱壳结构的安全余量方程，并进行了数值计算分析，研究了分布轴对称、分布非对称对薄壁圆柱壳屈曲可靠度的影响，建立了外压作用下的非轴对称初始缺陷薄壁圆柱壳结构临界屈曲安全余量，并进行了数值分析。建立了分布轴对称、分布非对称以及局部对称缺陷薄壁圆柱壳结构，开展了基于可靠度的屈曲容许临界荷载设计方法研究。更多还原

【Abstract】 Initial imperfection is one of the most basic imperfections of real engineering structure. Buckling probabilistic performance study of structure with initial imperfection is the important application of structural reliability theory in the field of modern structural stability theory. Buckling allowance loading design based on reliability of structure with initial imperfection, which can consider the random characteristics of imperfection and its variables, is more appropriate for engineering practice situation. Herein, the research of buckling safety design of imperfect structure based on structural reliability exhibit certain theoretical and application significance.This thesis carried out the research of initial imperfection influence on structural buckling reliability.Based on the study of a number of references, the thesis puts forward a safety buckling load design method based on the maximal variation velocity of loading vs displacement. Traditional stable buckling and unstable buckling all have been unified as general bifurcation buckling. According to beam-column theory and AFOSM, the buckling safety margin equations of structure with initial random eccentricity and deflection have been founded. Combination loading including concentrate loading, uniform distribution loading and end moment loading, have been analyzed here, where buckling safety margin equations also have been founded. The influence of initial imperfection on structural buckling reliability has been analyzed. And then, buckling reliability of frame structure with initial geometrical imperfection has been studied by the critical combination loading distribution. Structure BCPL buckling safety margin equation with the variable of non-dimensional imperfection amplitude is derived finally.更多还原