Wheel-Rail Contact Forces Monitoring Based on Space Fixed-Point Strain of Wheel Web and DIC Technology

Abstract

AbstractCondition monitoring of wheel-rail contact forces has great significance for evaluating the dynamic performance of railway vehicles. Instrumented wheelset method has disadvantages that strain gages are complicated in arrangement, wheel-rail forces decoupling is difficult, and the accuracy is low. Combined with the digital image correlation (DIC) technology, this paper introduces a novel non-contact monitoring method based on space fixed-point strain on the surface of wheel web. Through the finite element modeling and simulation analysis of wheelset, it is found that the strain at some space fixed-points on the surface of wheel web is linear with lateral/vertical forces. Based on this conclusion, the numerical equation between single space fixed-point strain and the lateral/vertical forces is established. Two point numerical equations can be decoupled to obtain the lateral and vertical force. The space fixed-point strain can be obtained by non-contact using the mature DIC technology and then achieve the simple and accurate measurement method of wheel-rail contact forces. It is verified by FEM simulation results that under the premise of using DIC technology to get space fixed-point strain of wheel web; the force monitoring method introduced in this paper can obtain the wheel-rail contact forces accurately and simply, which has important theoretical guiding significance for wheel-rail contact forces monitoring.KeywordsWheel-rail contact forcesCondition monitoringSpace fixed-point strainDIC