For detailed stress distribution analysis of bondlines, non-linear finite element analy-\udsis (FEA) is necessary. Depending on the load case in relation to shear and tension/\udcompression adhesives show a different behaviour of the yield point [\ud1\ud], which is e.g. \udincluded in the Mahnken and Schlimmer [\ud2\ud] model. State of the art for biaxial tested \udadhesive material-characteristics is the use of bonded tubular butt joints under variable \udtorsion and tension loads. Important for the quality of the determined material values \udis the alignment of both tubes. The quality is significantly improved, if both tubes are \udaligned perfectly coaxial. Also, the bondline has to be free of voids. In previous work \ud[\ud3\ud], Wölper investigated the effects of coaxial and angle deviations for the results of \udmaterial characteristics using FEA. A slight deviation has a strong negative impact to \udthe results. Particularly for thin film-adhesives with elevated curing temperatures, the \udchange of viscosity of the adhesive and the thermal expansion of the tubes must be \udconsidered. Previous investigations regarding the manufacturing of the specimens \udshowed shortfalls in joining and curing them. Due to voids, geometric deviations or \udpoorly-bonded tubes, no reliable results were achieved yet. Therefore, a new assembly-\uddevice is developed and tested. The results show well joined tubes without a signifi-\udcant angle deviation and with an average of 40\ud μm in coaxial deviation. The thickness \udof the bondline can be adjusted and is constant over the whole diameter. The new \udjoining-device enables the testing of tubular butt joints to determine biaxial material \udvalues of thin higher-temperature-cured film-adhesives. The device is patented to DE \ud102017114538.9.
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