Designing efficient grid structures considering structural imperfection sensitivity. (1st February 2020)

• Record Type: Journal Article
• Authors: Liu, Fengcheng; Feng, Ruoqiang; Tsavdaridis, Konstantinos Daniel; Yan, Guirong
• Is Part Of: Engineering structures. Volume 204(2020)
• Publication Date: 2020-02-01
• Subjects: Space grid structure -- Shape optimisation -- Imperfection sensitivity -- Bending strain energy -- Redundancy; Structural engineering -- Periodicals; Structural analysis (Engineering) -- Periodicals; Construction, Technique de la -- Périodiques; Génie parasismique -- Périodiques; Pression du vent -- Périodiques; Earthquake engineering; Structural engineering; Wind-pressure; Periodicals; 624.105
• DOI: 10.1016/j.engstruct.2019.109910
• Languages: English
• ISSNs: 0141-0296

Abstract

Highlights: An improved shape optimisation method is proposed. Bending strain energy ratio is used as constraint in the process of optimisation. An index called structural overall redundancyis proposed. The improved method can obtain an efficient grid structure. Abstract: At the initial design stage of a grid structure, shape optimisation is an effective way to find the optimal structural form. However, most of the shape optimisation methods do not take into consideration the imperfections, thus the actual buckling load capacity of the optimised structure is usually low. In this paper, an improved shape optimisation method is proposed, one that is considering the effect of structural imperfection sensitivity. In this method, the bending strain energy ratio is taken as a constraint, and when the total strain energy decreases, yet there is a certain proportion of bending strain energy in the structure. Consequently, the resulted shape is not sensitive to the initial geometry imperfection, and therefore, an efficient structure with higher buckling load capacity and low imperfection sensitivity is obtained. In order to evaluate the redundancy performance of the optimised structure, an index called structural overall redundancy, based on damage model is proposed herein. The damage model is simulated by removing a key rod of the structure. The results demonstrate that the overall redundancy of the structure obtained by the proposed method is higher than that obtained by the traditional method, thus an optimal design of a grid structure is obtained.