Impact Mechanism of Member Initial Stress on Space Truss
Du Xinxi,Liu Maoqing,Wang Jie and Chen Baolin
DOI:10.11835/j.issn.1674-4764.2013.04.009
Received ,Revised , Accepted , Available online July 01, 2015
Volume ,2013,Pages 55-59
- Abstract
To reveal distribution characteristics of member initial stresses, nine experimental prototypes in span of 4 m, 5 m and 6 m were employed. To analyze effects of member initial stresses on ultimate capacity of space truss, a prototype in span of 6m was applied. Meanwhile, the results were compared with those of Abaqus nonlinear FEM which were based on elastic-perfectly plastic model and Marshall Mode. Initial stress test shows that some initial stresses approach or even exceed stability stress. It is shown that the test ultimate capacity decreases by 17.9% than that of Marshall Mode, and the safety margin of structure is just 1.25. The impact mechanism of member initial stress consists in damaging structure initial symmetry, producing member initial bending and prompting press member buckling in advance. Member initial stress must be taken into account when space truss design, especially Fully-Stress design, is conducted.