Effect of Random Distribution of Member Length Imperfection on Collapse Behavior and Reliability of Flat Double-Layer Grid Space Structures

Abstract

The existence of initial imperfections in manufacturing of double-layer space structures having thousands of members is inevitable. Many of the imperfections, such as member length imperfections, are all random in nature. In this paper, the probabilistic effect of member length imperfection in the load bearing capacity of double-layer grid space structures with different types of supports have been investigated. First, for the member length imperfection of each member, a random number is generated from a normal distribution. Then, the imperfections are randomly distributed amongst the members of the structure. Afterwards, the ultimate bearing capacity of the structure is determined by using nonlinear analysis and this procedure is frequently repeated using Monte Carlo simulation method. Ultimately, based on the maximum values of bearing capacity, structure's reliability diagrams are obtained. The results show the sensitivity of the collapse behavior of double-layer grid space structures to the random distribution of initial imperfections.