چكيده به لاتين
Unified structure manufacturing is extremely difficult due to installation challenges, geometric complexities and various other problems, therefore one cannot always refrain from employing joints. Yet, joints are considered to be critical points, therefore composites, thanks to their stiffness, strength and flexibility, are used alongside metals in Complex structures.
The present study is focused on pull-through loadings, which damage bolted joints in composite planes. To this end, we discussed composites and various joint types, then each joint type is modeled and simulated in ABAQUS, a finite element software, under static loads and various damage theories including maximum stress, maximum strain, etc. are explained.
Afterwards, we investigated the effects of various factors, such as variations in the thickness of multiple composite layers, friction and addition of washers to the bolted joints, on damages and force-displacement graphs and carried out a comparison between these factors. The obtained results showed with an increasement in composite thickness cause more initial sub-critical failure load. In addition it was found that initial damage occure at lower displacement. Also washer disperse stress distribution and increase initial sub-critical failure load.
Sandwich specimen consistes of carbon/epoxy skins and foam core are manufactured and tested to verify numerical simulation experimental finding are in acceptable correlation with numerical simulation results.
