Experimental and numerical investigation of the structural and vibrational behavior of a composite and sandwich structure

This thesis study consists of three different parts. In the first section, the effects of the unit cell angle on the structural behavior and free vibration behavior of a periodic core composite sandwich plate with a hexagonal profile were examined by the unit cell method and finite element method. In the second section, the effects of the holes and the masses added in the plates consisting of Aluminum (Al1100), Titanium (TiGr5), Aluminum and Titanium layered metal composite (5TMK) produced by ultrasonic production method and Carbon fiber reinforced polymer composites (CFRP) on the vibration behavior of the plates. were examined and compared with each other. In the third and last section of the thesis, traditional and re-entrant honeycombs made of polypropylene material were produced by 3D additive manufacturing method. Modal tests of the produced honeycomb structures were carried out experimentally and numerically, and the natural frequency results obtained were compared with each other. Additionally, the thickness of the hybrid honeycomb structures has been optimized and their vibration isolation performance has been improved