Abstract
This study aims to evaluate the fatigue durability of a cowcatcher and optimize its structure. The cowcatcher, which serves as the crucial component of electric multiple units, generally influences the electric multiple units operating security and stability. A finite element model considering material properties and geometry sizes of the cowcatcher is established for structural strength analysis. Based on the P-S-N curve, the nominal stress method is introduced to analyze the fatigue durability of the cowcatcher. Considering influences of input variables such as elastic modulus, Poisson ratio, loads, and plate thickness on the fatigue durability, the parametric model of cowcatcher is built. In addition, three-level fractional factorial design is chosen to ascertain the location of sampling points in the above variables’ sampling space. The response surface of the cowcatcher is fitted using Kriging model. Then, a non-linear programming by quadratic Lagrangian algorithm is proposed for optimizing the cowca...
Highlights
The cowcatcher mounted at the underframe of electric multiple units (EMU) is capable of cleaning up obstacles from the track and easing impacts in crashing
It is important to predict the service life of the EMU cowcatcher based on nominal stress approach and fatigue damage accumulation rule by means of ISIGHT 5.6 and finite element (FE)-SAFE 6.4 platforms
As a stable gradient optimization, the non-linear programming by quadratic Lagrangian (NLPQL) algorithm expands the objective function by two-order Taylor series and linearizes the constraints based on response surface methodology (RSM) to obtain the design point via disposing the quadratic programming, for the ultimate objective of acquiring an improved design on each iteration, until the result converges to the optimal design
Summary
The cowcatcher mounted at the underframe of electric multiple units (EMU) is capable of cleaning up obstacles from the track and easing impacts in crashing. Ding and Zhao[2] adopted a new energy absorbing structure and filling material with the application of collision-resistant system design based on LS-DYNA simulation. Most of them focused on deterministic analysis which regarded design variables as specific values.[10] uncertainties are ineluctable in many aspects of machining dimensions, material properties, load variations, non-linear degradations,[11,12,13] and other uncontrolled variations.[14,15,16,17] Probabilistic analysis is required to quantify these uncertainties, especially its effects on the fatigue behavior of components.[17] it is important to predict the service life of the EMU cowcatcher based on nominal stress approach and fatigue damage accumulation rule by means of ISIGHT 5.6 and FE-SAFE 6.4 platforms. The input design variables, including the plate thicknesses, loads, and material properties, are given as
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
