Approaches to assessing the stress-strain state of freight car spring suspension coils
Objective: To assess static strength and determine the stress-strain state (SSS) of the spring suspension coils of a freight car bogie, based on analytical approaches and the ﬁnite element modeling. To substantiate permissible stresses ensuring the strength of the spring. Methods: Analytical expressions and the ﬁnite element method have been applied. Results: Analytical approaches to calculating the static strength of springs are recommended at the preliminary stage for express analysis of the spring strength. Finite-element modeling allows us to take into account the speciﬁcs of ﬁxing the spring suspension coil and to determine more accurately the coil SSS under combined loading. If torsion test results are available and positive static compression test results are obtained (absence of residual deformation), we recommend evaluating the spring strength with an increased coefﬁcient of 1,15 of the yield strength. Practical importance: The developed ﬁnite element model of the coil with boundary conditions can be used to estimate the spring suspension coil SSS of various types of rolling stock