Study on structural system reliability for commercial motor-vehicles of passenger transport frame structure

Aiming at the problem that traditional bus body frame structure design does not take into account the problem of constraint function uncertainties, the reliability of bus body frame structure with several random variables was analyzed. Three-dimension spatial frame structure system is established by spatial beam element. The static response of structural system is analyzed by using the stochastic finite element method, and the main failure modes are identified by using the branch-and-bound method. The correlation coefficients of failure modes safety margins are calculated by linearization research of safety margin functions of the main failure modes, and the reliability of bus body frame structural system is evaluated by PNET method. Calculation example results indicate the method is close to the practical working condition and has high calculate precision, provides theory foundation for the reliability optimal design of bus body frame structure system.