Numerical study of the local behaviour of adhesive bonds under dynamic loading

Nowadays, adhesively bonded structures are widely used in the transport sector for the development of lightweight vehicles. In order to guarantee passenger safety, it is thus necessary to understand the behaviour of such assemblies under dynamic and combined loadings. This paper presents a numerical study of the local behaviour of adhesively bonded assemblies under dynamic loading. In the first part, the ASTM D950-03 block impact test is studied. This device does not enable a homogeneous loading of the adhesive and causes stress concentrations. On the basis of existing quasi-static works, strategies are then implemented at a local scale. By combining a specific substrate geometry and by limiting the stiffness gradient between the substrates and the adhesive, results show that it is possible to obtain a qualitatively acceptable stress fields in the adhesive for mechanical characterization under dynamic loadings. The Arcan TCS device mentioned below uses such solutions to characterize the mechanical behaviour of bonded joints subjected to combined quasi-static loadings. In this study, the question of its extensibility to dynamic loadings by the use of an impactor guided into a drop tower is investigated. A dedicated finite element model is built under the plane stress assumption. The stress distributions in the adhesive are analysed through time and space for several loading conditions. The stress versus time signals are then compared with the results coming from modal analysis in order to highlight the vibration behaviour of the device, directly linked to the configuration.