The fatigue strength of a car seat is divided into two parts: the fatigue life of the seat cushion and the fatigue strength of the skeleton. For the fatigue life of the cushion, the large deformation and nonlinear finite element method is generally used for research. In 1986, Patrick Glance proposed a simplified model of the seat cushion of the car, which divided the seat cushion into a plurality of heights and cushions. In the cylindrical unit, the column is subjected to pressure without lateral deformation, and the cylinders interact with each other by shear stress.
This model can be used not only for the strength analysis of the seat cushion, but also for the calculation of the body pressure distribution. In addition, in engineering practice, people also try to study the performance of the cushion material by the fatigue test method. The fatigue strength of the skeleton involves the reliability design, the cumulative damage theory of the metal material, etc. The main method is to study.
For a mechanical product made up of many parts (such as airplanes, tanks, cars, etc.), the design based on theoretical analysis is difficult to prevent its failure in service. Although there are many forms of failure, most of them are fatigue failures. Some sources report that fatigue failure accounts for 50% to 90% of the total number of failures of mechanical zeros and components.
