Study On Seat Comfort Of High-speed Train Based On Dynamic Analysis Of Human Lumbar Spine

With the continuous development of the railway industry,the high-speed rail has become a common trend of the world’s railway development.The high-speed railway is developing in the direction of the high-density and high-speed.At the same time, people have a higher requirement for the high-speed train.Safety, comfort and convenience become the high-speed train seat design goal.The high-speed train seat is an important part of the high-speed train, directly related to the passenger riding comfort. The human spine not only carries the weight of the body and load, but also absorbs the vibration which caused by the external environment. Incorrect sitting position causes the spine abnormal bending. In a long time incorrect sitting position will produce physical pain and mental fatigue, and even cause the spine have a chronic injury. Therefore,it is very important for the design of seat comfort to implement static and dynamic analysis of the spine by the finite element method with the knowledge of spinal biomechanics.In the process of building the finite element model of the lumbar segments,this thesis uses the software of Mimics to extract contour datas of L1-L5lumbar segments based on the spiral CT data and obtain three-dimensional model of lumbar segments;import three-dimensional model of lumbar segments into the software of Hypermesh,process the model and build a whole finite element model of the lumbar spine.The next section is the static and dynamic analysis of the lumbar spine finite element model.Import the finite element model of lumbar segments into the finite element software of Abaqus and analyze static state of the finite element model under different postures.By comparing the displacement and stress distribution under different postures, get the body comfortable sitting and provide a reference for the static seat comfort design.Carry out the modal analysis of the lumbar segments by using Abaqus and get the natural frequencies and model shapes of the lumbar segments.Carry out the steady-state dynamics analysis to the lumbar spine model based on the modal analysis, and obtain the special positions’ displacement response curve with the mutative excitation frequency.The results provide references for the dynamic seat comfort design.Introduce the damped power spectrum of track irregularity into the structure of the lumbar spine, and analysis the response of the lumbar spine under the different track irregularity by obtaining the special positions’ displacement response curve with the mutative frequency.Biomechanics and finite element theory are used in this thesis, combined with modern CT and reverse engineering, build and analyze the finite element model of lumbar segments. It provides references for the seat comfort design. The result is very significance for the high-speed train seat design.