The Experimental Study of Effects of the Degree of Bolt Tightness of MERO Type Jointing System on the Rigidity of the Double Layer Grids

A search of the literature reveals that the studies related to the effects of the degree of bolt tightness on the behaviour of the joints and consequently on the response of the space structures are rather limited. The experimental study of the effects of the bolt tightness on the rigidity of the structures of the compression members of the space structures is the objective of the present research. In order to study of the effect of bolt tightness on the rigidity of the space structures, several experiments were carried out on 10 meters by 10 meters MERO type double layer grids. The grids were assembled with different degrees of tightness of the bolts and a concentrated load was applied at the central node of upper layer of the grids and deflections of a number of bottom layer nodes were measured. The studies has indicated that the degree of bolt tightness has a significant effect on the rigidity of the space structures. In this paper, Different aspect of the bolt tightness on the behaviour of space structures has been considered and some recommendations have been presented in the context of the design assisted by testing.