摘要
Abstract
Based on a practical engineering project,this paper investigates an irregular single-layer cylindrical reticulated shell structure,and establishes finite element models in MIDAS and NIDA.The first-order buckling mode is used as the structure global initial imperfection,and the PEP element in NIDA is used to simulate the member imperfections.In the analysis,both geometric and material nonlinearity are considered.By comparing the member stress ratios calculated by the traditional effective length method,the second-order elastic P-Δ method,and the direct analysis method,the ultimate bearing capacity and the distribution of failed members under the ultimate state are analyzed.This verifies the reliability of the direct analysis method in the design of irregular reticulated shell structures.By comparing the member stress ratios calculated by the traditional effective length method,the second-order elastic P-Δmethod,and the direct analysis method,the ultimate bearing capacity and the distribution of failed members under the ultimate state are analyzed.This verifies the reliability of the direct analysis method in the design of irregular reticulated shell structures.According to the results of direct analysis method,the key factors of the ultimate stability bearing capacity are analyzed,and the effective length coefficients are back-calculated to obtain more accurate results in linear calculations.In addition,in order to determine whether the member imperfections should be considered in nonlinear calculations,the effects of slenderness ratio and moment stress ratio considered,and a relationship formula is fitted,which provides a reference for the rapid evaluation of structural schemes and practical design of similar projects.关键词
直接分析法/异形单层柱面网壳/稳定性分析/极限承载力/关键构件分布/计算长度系数/非线性计算Key words
direct analysis method/irregular single-layer cylindrical reticulated shell/stability analysis/ultimate bearing capacity/distribution of critical members/effective length coefficient/nonlinear calculation分类
建筑与水利
