| With the continuous development of the length of the highway and road between cities, the number of high-level sleeper buses and trains berth comparts is also rise. With the economic development and the improvement of people's life, the comfort of sleeper coaches is demanded to improve. Because the passengers lie on the bus berths, it is different with the standing and seated position. It is urgent to evaluation the vibration comfort of the recumbent persons, the comfort evaluation adapted to the vibration of Chinese recumbent passengers is profound.In order to establish the criterion of sleeper buses, firstly a number of experiments of the berths on sleeper buses and trains have been done. The buses used to test are a common sleeper bus and a high-level sleeper bus riding on the second to the fourth class roads, as well as on the highway. The results of the experiments have showed that the vibration of the head and the buttock mainly take place in the frequency of 0.5~20Hz, the vibration acceleration of the passenger's head on the high-level sleeper bus at highway does not exceed 1.20 m/s2, the buttock's vibration acceleration is not more than 1.00m/s2, however the acceleration of the legs' vibration is less than 0.50m/s2. The vibration experiments of trains were done on the hard and soft berths in the mountain diverged line and the plain main railway, the data showed that the vibration of the passenger's head and pelvis mainly took place in the frequency of 0.5-15Hz, under this range, the acceleration of head's vibration don't exceed 0.80m/s2, the buttock's vibration acceleration is not more than0.40m/s , the legs' vibration acceleration is less than 0.30m/s . All the data showed that, the head and buttock are the sensitive vibration parts, the vibrations of the head and buttock are comparably large and their vibration curves are like. The vibration of head has a indistinctly effect on the comfort of recumbent person. The legs' vibration is small and fluctuated largely, so the legs' vibration can be ignorant to enhance the accuracy. In light of the analysis data results of these experiments, vibration comfort evaluation of human in recumbent position should be done in accordance to the vibration of recumbent passenger's head and buttock, referring to the international standard ISO2631/1-1997(E), as well as on the base of correlate studies ofwhole-body vibration in recumbent position. Accelerations of the head and buttock measured have been weighted twice to get at the frequency-weighted acceleration at the buttock and head, the weighted acceleration then is used to evaluate the comfort of human vibration in recumbent position. The results of experiments analysis data put also up some reference to establish the Chinese national standard "comfort evaluation of human exposure to whole-body vibration in recumbent position"(GB/T 18368-2001) and auto trade standard "the tests method of sleeper buses ride comfort with random input"In light of the correlate national standard and auto trade standard, the vibration tests data of buses and trains were studied. The results showed that, the comfort rates of common sleeper bus on three and four class roads are fourth and fifth grade at average. The weighted accelerations on the back part of the advanced sleeper bus on highway is between 0.50~0.68m/s2, its comfort is 3 class degree; the weighted vibration acceleration of train's in the beneath soft berth on plain main line is 0.5~0.6m/s2, and the comfort degree is 3 class; the upward berth vibration comfort is 2 class. So the evaluation method and the comfort degree arranged adapted to our county state.With the high-level sleeper bus and on the basis of vibration theory, Different stiffness and damp berths according to the head, pelvis and the legs respectively have been used, as well three types of pillows under the head. The results showed the vibration transmitted to body can be deceased indistinctly with the designed berth. The vibration with pillow of buckwheat nut can decrease 25% more than that with... |
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