In this study, the fatigue and vibration analysis were performed by using Solidworks program to investigate the damage percentage, life cycle and vibration mode depending on the types and positions of load applied to the table (Cases 1, 2, 3, 4). The farther the point of action of the load was, the more the fatigue damage and stability of the table were greatly reduced. The life cycles of Case 1 and 4 were over 100,000 cycles and the fatigue damage was less than 70%. From the vibration analysis, five modes and natural frequencies of Case 1 were confirmed. As the natural frequency increases, the shape of the corresponding mode is predicted not to be deformed.
This study investigates the safety and life during the fatigue load by the configuration of seat frame. On back frame at seat frame, the life and damage are analyzed. The deformation and equivalent stress are compared with each other through the vibration analysis, The result of this study through the analysis can be applied to develop the automotive seat frame with durabilty and safety.
본 연구에서는 고강도 운동 후 전신진동이 근피로도 감소와 심박회복율에 미치는 효과를 알아보고자 하였다. 피험자 는 총 20명으로 진동을 제공받는 그룹과 진동을 제공받지 않는 그룹으로 구성되어 있다. 고강도 운동은 경사 8.5도와 보행속도 4km/h를 30분간 제공하였고, 그룹별 진동유무별 의자형 진동기 위에서 30분간 휴식을 취하였다. 전신진동자 극은 10Hz의 진동주파수와 5mm의 진폭을 제공하였다. 진동유무별 피로도 감소와 심박안정화 효과를 검증하기 위해 혈중 젖산농도와 실시간 심박수 변화를 측정하였다. 실험결과, 진동을 제공받는 그룹에서 95.2% 수준의 더 큰 근피로도 감소결과와 50.67%의 더 빠른 심박회복율 결과를 보였다. 이는 고강도 운동 후 전신진동이 근육속 혈관을 지속적으로 자극하여 운동 후 초과산소섭취를 빠르게 해소하고 혈액순환 기능을 증진시켜 피로도를 감소시킨다. 고강도 운동 후 전신진동을 이용한 휴식은 노약자나 여성들에게 운동 후 다른 육체적 활동 없이 마무리운동으로 긍정적 효과를 기대할 수 있다.
This paper presents a method for the assesment of vibration fatigues in engine exhaust system. Analysis technologies by virtual model can reduce the number of physical tests and development cycles. The prediction processes are based on the construction of FE model for the exhaust system, normal mode analysis, and frequency response analysis. The analysis results(1st mode: 152Hz) of eigen frequencies are compared with the modal test results(1st mode: 151Hz). And frequency response analysis for accelerations and stresses at critical locations were also presented. The analysis method could be applied to assess the vibration fatigue for the engine exhaust manifold. As a result, maximum stress occurred at the end of diffuser and its frequency shows around 1st natural frequency of exhaust system. It shows a good agreement between numerical and experimental results.
This study analyzes about Bicycle saddle in operation through the analysis of Fatigue life and structural safety, equivalent Stress, maximum deformation. Maximum equivalent stress is analysis applied with force. The structural result of this study can be effectively utilized with the design of Bicycle saddle by investigating prevention and durability against its damage.