Composites Research

The Korean Society for Composite Materials (한국복합재료학회)
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Measurement of Dynamic Strains on Composite T-Joint Subjected to Hydrodynamic Ram Using PVDF Sensors

PVDF 센서를 이용한 수압램 하중을 받는 복합재 T-Joint의 동적 변형률 측정

  • Go, Eun-Su (Department of Aerospace Engineering, Chungnam National University) ;
  • Kim, Dong-Geon (Department of Aerospace Engineering, Chungnam National University) ;
  • Kim, In-Gul (Department of Aerospace Engineering, Chungnam National University) ;
  • Woo, Kyeongsik (School of Civil Engineering, Chungbuk National University) ;
  • Kim, Jong-Heon (Agency for Defense Development)
  • Received : 2018.05.25
  • Accepted : 2018.09.14
  • Published : 2018.10.31
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Abstract

The hydrodynamic ram (HRAM) phenomenon is one of the main types of ballistic battle damages of a military aircraft and has great importance to airframe survivability design. The HRAM effect occurs due to the interaction between the fluid and structure, and damage can be investigated by measuring the pressure of the fluid and the dynamic strains on the structure. In this paper, HRAM test of a composite T-Joint was performed using a ram simulator which can generate HRAM pressure. In addition, calibration tests of PVDF sensor were performed to determine the circuit capacitance and time constant of the measurement system. The failure behavior of the composite T-Joint due to HRAM pressure was examined using the strain gauges and a PVDF sensor which were attached to the surface of the composite T-Joint.

수압램 현상은 전투용 항공기의 주요 전투 손상 중 하나이며, 항공기 기체 생존성 평가에 중요한 영향을 미친다. 수압램 효과는 유체-구조물간의 상호관계를 통하여 나타나며, 구조물의 동적 변형률을 측정하여 파손 거동 및 파손 여부를 확인할 수 있다. 본 논문에서는 수압램 현상을 모사할 수 있는 수압램 시험 장치를 이용하여 수압램에 의한 복합재 T-Joint의 파손 시험을 수행하였다. 또한 계측기기의 입력 정전용량과 시간 상수 확인을 위해 PVDF 센서 보정 시험을 수행하였다. 복합재 T-Joint에 스트레인 게이지와 전하증폭기를 사용하지 않은 PVDF 센서를 부착하여 수압램 현상에 의한 복합재 T-Joint의 동적 변형률을 측정하였다. PVDF 센서와 스트레인 게이지의 동적 변형률을 이용하여 복합재 T-Joint의 파손 거동 및 파손 여부를 확인하였다.

Keywords

References

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