Structural adhesive bonded joints in engineering – drafting design rules

Abstract

This paper introduces methods to draw up design rules to calculate the resistance of adhesive bonded joints for structural applications. In the past, design rules were based on allowable stresses, while the current rules verify limit states. Best known is the partial safety factor approach. This method enables to distinguish different reliability levels by using load and material factors. These factors take into account the stochastic nature of both load actions and resistance of a structure. In case of adhesive bonded joints also the durability effects have to be considered. To calibrate the partial safety factors both engineering judgement and probabilistic techniques can be used. Since the experience with design rules for structural adhesive bonded joints is limited, the use of probabilistic techniques seems to be a promising opportunity to draft design rules. To do this it is necessary to have a proper description of the nature of adhesive bonded joints. Special attention should be paid to the statistical distribution of the resistance and the effects of durability. An example of drafting a design rule illustrates the current possibilities. To conclude this paper guidelines are formulated how to draw up design rules.