진동특성을 고려한 차륜형장갑차 브래킷 손상에 대한 실험 및 해석적 분석
Experimental and numerical analysis of the bracket failure for wheeled armored vehicle with vibration characteristics
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초록
The bracket to fix the coolant pipe of the powerpack has been frequently damaged during the operation of the wheeled armored vehicles. This study was concerned with the causes of the bracket failure and the direction of the improvement. First, the failure pattern was observed on the failure surface of the bracket. Then, the stresses and acceleration data were measured to find vibration characteristics of the bracket using strain gauge and acceleration sensors, respectively. The cause of failure was found to be the fatigue due to the resonance of the bracket at the idle rpms of the engine. To avoid the resonance, the shapes of the brackets are presented based on the modal analysis. The improved shape was required to reduce the resonance frequency by reduction of its stiffness because of the extents of the engine rpms. The improved shape for avoiding the resonance results in the acceleration level decreased to 73% of the previous one. In addition, the maximum stress, from the static analysis, was decreased to 67% of the previous one. Conclusively, the failure of the bracket was the fatigue due to the vibration resonance, and to avoid the failure the stiffness of the bracket was decreased. It is expected that the reliability of the powerpack will be improved for the wheeled armored vehicles.
Abstract
The bracket to fix the coolant pipe of the powerpack has been frequently damaged during the operation of the wheeled armored vehicles. This study was concerned with the causes of the bracket failure and the direction of the improvement. First, the failure pattern was observed on the failure surface of the bracket. Then, the stresses and acceleration data were measured to find vibration characteristics of the bracket using strain gauge and acceleration sensors, respectively. The cause of failure was found to be the fatigue due to the resonance of the bracket at the idle rpms of the engine. To avoid the resonance, the shapes of the brackets are presented based on the modal analysis. The improved shape was required to reduce the resonance frequency by reduction of its stiffness because of the extents of the engine rpms. The improved shape for avoiding the resonance results in the acceleration level decreased to 73% of the previous one. In addition, the maximum stress, from the static analysis, was decreased to 67% of the previous one. Conclusively, the failure of the bracket was the fatigue due to the vibration resonance, and to avoid the failure the stiffness of the bracket was decreased. It is expected that the reliability of the powerpack will be improved for the wheeled armored vehicles.
참고문헌 (9)
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