The Seated Human Modeling Based On Body Pressure Distribution And Vertical Vibration Response

In recent years,more and more attention has been paid to seat comfort.Seat comfort has gradually become one of the key indicators of the automotive design.Study of seat comfort by the use of an appropriate human-seat model is time and cost saving,The static body pressure distribution on the human-seat interface and the vertical vibration response of the human body are two most important indicators of the seat static comfort and dynamic comfort.A static body pressure model of seated body and a vertical vibration model of seated body is respectively necessary for the static comfort and dynamic comfort.Aiming at the seat static comfort and dynamic comfort,a seated human model for predicting the static pressure distribution and a seated human model for predicting vertical vibration response of human body are established,and a custom-contoured cushion design method based on interface pressure mapping is proposed.Based on the 50 th Hybrid ? collision finite element model,geometry,material and joint of the Hybrid ? finite element model are modified,a posture adjustable static pressure model of Chinese 95 th seated body is established,and the mass percentage of the segments of the human model is verified with the previous experimental research results.The characteristic curve of the foam cushion material is obtained by the uniaxial compression test.A finite element model of rigid-cushion seat and a finite element model of foam-cushion seat are established according to the real seats.The accuracy of the human-seat models is verified by the static pressure distribution experiment on the rigid-cushion seat and the foam-cushion seat.the influence of seat height,cushion angle and backrest angle on static pressure distribution and buttocks tissue stress is analyzed by the use of human-seat model simulation.Based on the static pressure model of seated body,the material of the human buttock tissue is simulated with linear elastic materials,and the stiffness and damping are applied to the joint rotation pair,and a vertical vibration model of seated body is established.Secondly,the mode of the human model is analyzed,and three order modes within 10 Hz are obtained(the first mode 1.39 Hz,the second mode 4.14 Hz and the third mode 4.60 Hz).The simulation is carried out in the condition that human model and rigid cushion seat are exposed on the vertical vibration without backrest support.The simulation results of the vertical apparent mass,the fore-and-aft apparent mass seat-to-head transmissibility and the dynamic pressure distribution can be in good agreement with the previous research results,the accuracy of the vertical vibration model of seated body is verified.The effects of the parameters of human model on the apparent mass,and the seat-to-head transmissibility are analyzed by the use of human model simulation.A custom-contoured cushion(CCC)design method based on interface pressure mapping is proposed,whose mapping function is obtained from the simulation pressure and deformation results(simulated pressure and deformation mapping method,SPDM method),The SPDM method can be customized according to the experimenter's body parameters,cushion's material curves and static pressure data.The SPDM method and the traditional TMCM method are used to design the CCCs respectively,the smoothness of the CCCs' surface and presssure distribution are compared with the two methods,The results show that the CCC surface designed by the SPDM method has better smoothness,and can better fit the shape of buttock,which help reduce pressure and improve comfort.