CAJ | 학술논문

利用等效弹性模量随机场来表征铸造缺陷的随机性，对含铸钢节点的钢管桁架结构进行概率有限元模拟，计算了结构整体性能对铸钢材料及钢梁钢管材料分散性的敏感度。然后，基于随机场局部平均理论，利用随机场网格描述铸钢节点缺陷概率分布随空间位置变化的特点，计算了结构整体性能指标对随机场离散后各随机变量的敏感度。最后，对随机场网格进行二次划分，得到能反映随机因素空间重要度的随机场网格，并大大减少了结构随机有限元计算的计算量。结果表明：含铸钢节点的钢结构的结构性能对铸钢材料弹性模量随机性的敏感度约为型钢钢管材料的3倍，铸钢材料的随机性是影响结构性能的重要因素；铸钢节点主管下侧受拉部位的材料对结构的刚度和稳定性影响较大，主管与支管相贯线部位的材料对结构强度影响较大，在跨尺度随机有限元分析中，相关区域在随机场网格细化和缺陷模型建立时应重点考虑。
이용등효탄성모량수궤장래표정주조결함적수궤성，대함주강절점적강관항가결구진행개솔유한원모의，계산료결구정체성능대주강재료급강량강관재료분산성적민감도。연후，기우수궤장국부평균이론，이용수궤장망격묘술주강절점결함개솔분포수공간위치변화적특점，계산료결구정체성능지표대수궤장리산후각수궤변량적민감도。최후，대수궤장망격진행이차화분，득도능반영수궤인소공간중요도적수궤장망격，병대대감소료결구수궤유한원계산적계산량。결과표명：함주강절점적강결구적결구성능대주강재료탄성모량수궤성적민감도약위형강강관재료적3배，주강재료적수궤성시영향결구성능적중요인소；주강절점주관하측수랍부위적재료대결구적강도화은정성영향교대，주관여지관상관선부위적재료대결구강도영향교대，재과척도수궤유한원분석중，상관구역재수궤장망격세화화결함모형건립시응중점고필。
The random fields of equivalent elastic modulus were used to characterize the randomness of casting defects,and the steel truss structure with cast steel nodes was simulated by probability fi-nite element.The sensitivity of entire structural performance to the dispersion of the material of cast steel nodes and the steel beams and pipes was analyzed.Then,based on the local average theory of random field,a set of random field grid was put forward to describe the characteristics of the proba-bility distribution of the defects along with the change of the spatial position,and the sensitivity of the entire structural performance to every stochastic variable in the dispersed random field was calcu-lated.Finally,the random field grid was again divided and the new random field grid can reflect the spatial importance of the random factor with great reduction of the computational quantity of the structural stochastic finite element.The results show that for the steel truss structure containing cast steel nodes,the sensitivity of the entire structural performance to the elastic modulus of cast steel ma-terial is about three times that of the steel tubes.The randomness of cast steel material is an impor-tant factor affecting the structural performance.The material in the lower part of the dominant tube located in the tensed zone has more influence on the structural stiffness and stability,and the line-in-tersecting material has more influence on the structural strength.In the two-scale stochastic finite ele-ment analysis,the related area should be focused on when refining the random field grid and establis-hing the defect's model.