Effects of the Adhesive Thickness and Residual Thermal Stress on the Torque Capacity of Turbular Single Lap Joints

접착제의 두께와 열 응력에 따른 조인트의 토크 특성

With the wide application of fiber-reinforced composite material in aircraft, space structures and robot arms, the design and manufacture of composite joints have become a very important research area because they are often the weakest areas in composite structures. In this study, the effects of the adhesive thickness, residual thermal stress on the torque capacity of the tubular single lap joints were studied. The torque capacity of the adhesive joints were experimentally determined and found to be inversely proprotional to the adhesive thickness. In order to match the experimental results to the theoretical analyses, the elastic-perfectly plastic material properties of the adhesive were used in the closed form solution. Also, the residual thermal stress of the joints were calculated by the finite element method and it was proved that the residual thermal stress could play an important role in the thick adhesive joints.

본 연구에서는 Fig.1과 같이 원형튜브 형태로된 시편과 실린더 형태의 시편을 Single Lap Joint의 형태로 접착하여 접착제의 두께에 대한 정적 비틀림 강도특성을 실험하였으며, 접착제의 경화시 외부에서 가해주는 열로 인한 열 잔류응력의 영향에 대한 연구를 수행하였다. 또한 이론적인 해석과 상용 프로그램인 ANSYS를 이용하여 유한요소해석을 병형하여 실험결과와 비교 검토하였다.