چكيده به لاتين
The design of automotive components today, with the aim of reducing their weight, is one of the key topics in terms of reducing fuel consumption, minimizing environmental pollutants, and cutting production costs. Recently, adhesive bonding has been widely used in many industries, such as the automotive industry, where the adhesive bonding properties improve mechanical behavior, reduce weight, and facilitate production. This research investigates adhesive joints under quasi-static and impact loading (Mode I, II, and mixed modes) under various conditions and the influence of strain rate parameters. The results show that as the strain rate increases, the maximum force and fracture energy increase in Mode I loading, while they decrease in Mode II. For adhesive joints under mixed mode loading, a single-edge adhesive joint sample was used, and the force-displacement curve is predicted using the fracture energy values and maximum adhesive stress in Modes I and II. To obtain the cohesive zone model, a compliance-based beam theory for dynamic loading is used, which benefits from not needing to record crack length during loading process that is difficult in dynamic analysis. In the equation for the fracture energy of adhesive joints under Mode I impact loading, wedge parameters such as the wedge angle and the distance from the impact point to the neutral axis are also involved, which enhances the accuracy of the results. After obtaining experimental test data, the results were compared with the finite element method using a strain-rate-dependent cohesive zone model to verify the results. Additionally, this study examined the effect of carbon nanotubes in the adhesive, finding that adding 0.3% by weight of carbon nanotubes increased the maximum force and fracture energy by 73% and 72%, respectively, under static loading, and by 16% and 16.2% under impact loading.
