Modelling of Dynamical and Statical Properties of a Car Seat with Adjustable Pressure Profile

Ing. Tien Tran Xuan

Doctoral thesis

Abstract:

- Derivation of the analytical model of the pneumatic spring system with lumped parameters + Analysis of the system using a multidisciplinary approach. + Numerical simulation of the model for different working conditions (constant stiffness and constant pressure mode, quasi-static load, dynamic load). + Investigation of the dynamical behavior of the system. Numerical simulation of transmission of acceleration. - Finding a solution to improve the system from the point of view of faster regulation of pressure inside the PSE Providing a theoretical basis for the idea of improvement and solution. Carrying out the numerical simulation of the improved system. - Investigation the influence of the PSE on transmission of acceleration. + Comparison of simulation results between original and improved systems. + Comparison of experimental results between original and improved systems. + Assessment of quality of the system improvement. - Creation of FEM model of the seat with adjustable pressure profile in interaction with a simplified model of the human body + Determination of suitable constitutive models for materials of seat's parts. + Modelling of interaction between a foam block with a PSE inserted and a mass to simulate the deformation of PSE and foam under static conditions. + Modelling of interaction between the car seat cushion with a PSE inserted and a simplified human body. + Calculation of the pressure profile in the contact zone between the seat and simplified human body. Comparison with the experimental results.

Abstract:

- Derivation of the analytical model of the pneumatic spring system with lumped parameters + Analysis of the system using a multidisciplinary approach. + Numerical simulation of the model for different working conditions (constant stiffness and constant pressure mode, quasi-static load, dynamic load). + Investigation of the dynamical behavior of the system. Numerical simulation of transmission of acceleration. - Finding a solution to improve the system from the point of view of faster regulation of pressure inside the PSE Providing a theoretical basis for the idea of improvement and solution. Carrying out the numerical simulation of the improved system. - Investigation the influence of the PSE on transmission of acceleration. + Comparison of simulation results between original and improved systems. + Comparison of experimental results between original and improved systems. + Assessment of quality of the system improvement. - Creation of FEM model of the seat with adjustable pressure profile in interaction with a simplified model of the human body + Determination of suitable constitutive models for materials of seat's parts. + Modelling of interaction between a foam block with a PSE inserted and a mass to simulate the deformation of PSE and foam under static conditions. + Modelling of interaction between the car seat cushion with a PSE inserted and a simplified human body. + Calculation of the pressure profile in the contact zone between the seat and simplified human body. Comparison with the experimental results.

Keywords

pneumatic spring, mathematical model, finite element method, constitutive model of material, contact pressure distribution, transmission of acceleration

Language used: English

Date on which the thesis was submitted / produced: 27. 12. 2019

Thesis defence

• Supervisor: doc. Ing. David Cirkl, Ph.D.

Technical University of Liberec

Faculty of Mechanical Engineering

Doctoral programme / field:
Mechanical Engineering / Applied Mechanics