随机结构功能模糊性的定量分析

针对率模可靠性理论应用中结构功能函数对结构安全(模糊事件)的隶属函数往往涉及主观因素的问题,对随机结构功能的模糊性产生根源进行了初步探索:利用等效水平截集处理功能函数的各随机分量,将连续随机向量映射为标准区间向量;在标准区间向量张成的凸域及其扩展空间中,研究截集水平和基于区间分析的结构非概率可靠性指标之间的定量关系.所得的非概率可靠性指标作为截集水平的连续严格单调增函数,能反映出结构功能的内在模糊性.初步找到了依据结构功能函数自身特征建立不涉及主观因素的安全隶属函数的桥梁. 

Qualitative and quantitative analysis of fuzziness for stochastic structure performance

To overcome the deficiency that the safety membership function of a structure or a system in safety engineering sometimes involves subjectivity in the application of profust reliability theory,a preliminary study was made for finding out the rootstock of the performance fuzziness of a random system.The performance fuzziness for a general random structure system was quantified by translating random vectors into standard interval vectors,that is,the density functions of random vectors was intercepted by an equivalent horizontal cut set.A non-probabilistic reliability index was proposed to measure the fuzziness of the structural performance,and the index was defined in a convex domain a subspace of the standard interval vector space and in its extended space.Not only does the index offer to what extent the structure is safe but also depicts to what extent the structure has been failure.Consequently the index is proposed to characterize the fuzziness for the structural performance.