Research On Lightweighting And Reliability Analysis Of Structure Of The Ballastless Rail Slab Accurate Adjustment Vehicle

Ballastless track technology has been widely used in construction of metro line in China.The installaton speed of rail slab directly affects the overall process of metro line construction.So,it is important to develop a special rail slab laying equipment to improve the efficiency of metro line construction.The ballastless rail slab accurate adjustment vehicle developed by a domestic company could be applied to the installation and repair of rail slab,which could greatly shorten the construction period of rail slab.In order to ensure the design quality,the static analysis and optimization of the structure were completed.Then the dynamic response and reliability of the vehicle’s structure were studied.The static performance of the vehicle’s structure was checked in software ANSYS.The results showed that the stress of all parts of the vehicle’s structure met the design requirements,but the static stiffness of the effective cantilever was insufficient.In order to improve the structural performance of the vehicle and reduce its weight,the deterministic optimization design of the vehicle’s structure was carried out by using ANSYS software and ISIGHT software.Firstly,the command stream file of the vehicle’s structure was compiled by the parametric design language and the file was integrated into the DOE component of ISIGHT software.Through the experimental design,the contribution of the design variables on the output response of the structure was obtained,and then some design variables for optimization were determined.Then,the response surface approximation model of the vehicle’s structure was set up and its error was within the allowable range.Finally,the response surface approximation model was optimized by particle swarm optimization algorithm.Results showed that the weight of the vehicle’s structure was reduced by 11.76%,and the structural performance was improved.The modal analysis of the vehicle’s structure was carried out by ANSYS software,and the mode of vibration and natural frequencies of the vehicle’s structure were obtained.The harmonic response analysis was performed by modal superposition method,and the sensitive frequency range of the vehicle’s structure was obtained,which provides a reference for avoiding structural resonance.The dynamic response of the vehicle’s structure under lifting condition was calculated by using transient dynamic analysis method,and compared with the static analysis results based on lifting dynamic load coefficient.The results showed that the relative error between them was small,and the structural dynamic stress under hoisting condition met the strength requirements,which verified the rationality of the value of hoisting dynamic load coefficient.Based on deterministic optimization design,the reliability of the vehicle’s structure was analyzed by advanced FOSM method and important sampling method.It was found that the reliability of the vehicle’s structure was insufficien,and the static displacement and strength of the structure could fail,so it was necessary to optimize the reliability of the vehicle’s structure.Important sampling data were imported into MATLAB software for reliability sensitivity analysis of random variables,and many key random variables were identified.In the optimization module of ISIGHT software,the reliability optimization of the vehicle’s structure has been completed.The results showed that the weight of the vehicle’s structure with reliability optimization was 8.63% lower than that of the initial structure,and the structure with reliability optimization was more reliable than the structure with deterministic optimization.