Analysis Method And Experimental Research On Hand-transmitted Vibration Characteristics Of Portable Pneumatic

When operating the portable pneumatic extinguisher,it will leave the operator in the vibration environment,which will cause related diseases of the arm system and body.Through the research on the vibration characteristics of the portable pneumatic extinguisher,the influence on the human arm is predicted,and the vibration damping device is designed reasonably and effectively,so as to reduce the harm of hand-transmitted vibration to human body.Taking the arm system of the portable pneumatic extinguisher operator as the research object,the arm system model with elbow angle of 60 °,90 ° and 180 ° were established based on the lumped parameter method,and the biomechanical motion equations were deduced.A standard vibration experiment platform was built to test,and the vibration responses of the arm wrist,forearm and upper arm were compared with the measured responses of the portable pneumatic extinguisher,in order to verify the accuracy of the standard vibration experiment platform.Through the standard vibration test data,the unknown parameters of the model were identified based on the least square method,and the predicted vibration responses of the model were compared with the measured responses of the portable pneumatic extinguisher,in order to verify the feasibility of the model prediction.Through the vibration responses obtained by the standard vibration experiment platform,the influence of hand force on hand transmission vibration responses was compared.The influence of elbow angle on hand transmission vibration responses was analyzed.The finite element model of the arm system was constructed,and the modal analysis was carried out,which was compared with the vibration frequency measured by the standard vibration experiment platform laboratory.The results demonstrated that the goodness of fit between the predicted vibration transmissibility response of the arm model and that of the standard vibration experimental platform was between 75% and 92%.The goodness of fit between the predicted vibration transmissibility of the arm model and that of the portable pneumatic extinguisher was around 77%.The goodness of fit between the predicted vibration absorption power response of the arm model and that of the portable pneumatic extinguisher was in the range of 68%?81%.Through comparative analysis,the resonance frequency of hand vibration was relatively concentrated in the range of 30-45 Hz,and working in this frequency range may increase the probability of arm vibration disease.The results demonstrated that the arm model can effectively predict the response characteristics of hand transmitted vibration when operating the portable pneumatic extinguisher.It could be used to analyze the influence of different factors on hand transmitted vibration,so as to provide a theoretical basis for the evaluation of human arm damage.The model is used to simulate the impact of hand-transmitted vibration on operators,which provides theoretical and data basis for the vibration reduction and protection of portable pneumatic extinguishers and lays a foundation for the research and development of its vibration reduction and protection mechanism.