Reliability and Sensitivity Analysis of Double-Layer Spherical Lattice Shells Using Multiple Performance Functions

The paper aims to investigate reliability,sensitivity and correlation of four double-layer spherical lattice shells (with rise-to-span ratio of 1/3,1/4,1/5 and 1/6) subjected to several different load levels.To deeply study the effect of external load,physical properties and geometric parameters of chords on reliability of lattice shells,cross-sectional area,modulus of elasticity and yield strength are defined as random variables,according to types of random variables in lattice shells.In order to clarify mechanical performance of four lattice shells,four output indexes,i.e.,maximal deflection,total plastic strain energy,number of yielding members/chords and total plastic strain,are defined into four performance functions,respectively.Furthermore,sensitivity analysis of all random variables to the above-mentioned performance functions and their correlations are extensively carried out.Finally,changing laws of reliability,sensitivity and correlation are investigated in detail with increment of rise-to-span ratio.