Systematic Approach and Design Procedure

The geometry, stiffness, and load carrying capacity of the adhesive joint are of central significance for thestructural behavior of the hybrid beam. This implies

Copyright by ASTM Int’l (all rights reserved); Tue May 6 12:07:08 EDT 2014 Downloaded/printed by

Rochester Institute Of Technology pursuant to License Agreement. No further reproductions authorized.

detailed knowledge of the mechanical values andthe durability of the adhesives. Particularly, discontinuities in the boundary areas require a closer examination.

The aim of the INNOGLAST project [5,6] is to derive simple design recom­mendations for bonded hybrid steel-glass beams, taking into consideration the common safety specifications of glass and thus avoiding extensive finite element calculations. In order to achieve this, a systematic approach was chosen, which is shown in Table 1.

The basis for this approach is the knowledge of the slip and elongation char­acteristics of the adhesive joint (Table 1, I) arising from the context of the build­ing structure, defining the structural and geometrical requirements for the adhesive joint. Depending on the connection type (Table 1, II), slip differential equations [7] are a useful means to determine the slip-strain behavior. In the next step, appropriate adhesives are chosen (Table 1, III) and the mechanical values are determined (Table 1, IV), and these are then carried over to small – scale push-out tests (Table 1, V-VI) and verified by large-scale component tests (Table 1, VII). Finally, design recommendations are derived (Table 1, VIII).

In the following, the detailed approaches for the choice of appropriate adhe­sive systems and the derivation of suitable mechanical values are presented, in particular with respect to durability and realistic bonding geometries.