Research of the strength and dynamic characteristics of a universal freight wagon using a mobile system

Abstract

This study is dedicated to advancing methodological approaches and instrumentation for the experimental analysis of structural integrity and running quality indicators pertaining to newly manufactured freight wagons, with the ultimate goal of certifying their operational suitability on public railway networks. This necessitates a comprehensive update of foundational theoretical principles, established testing methodologies, and measurement equipment. A central proposal involves the strategic replacement of dedicated laboratory wagons with advanced mobile digital measurement systems. Furthermore, the work introduces a novel approach for evaluating critical running quality metrics - specifically, the stability margin coefficient and vertical dynamics coefficients - achieved through the precise measurement of stress distributions within the wheel disc of a freight wagon's wheel set. The research employs an empirical methodology focused on quantifying wheel-rail interaction forces. This is accomplished by capturing and analyzing deformation patterns within critical structural zones of the wheel, enabling the subsequent assessment of wagon running quality performance under actual service conditions. Additionally, the work rigorously substantiates the imperative need for modernizing both software (SW) and methodological solutions. This modernization is essential for accurately evaluating the dynamic characteristics of both newly constructed and modernized rolling stock, currently being produced by Ukrainian wagon manufacturing facilities. The research provides robust justification for the operational and technical feasibility of transitioning from traditional laboratory wagons to sophisticated, compact mobile diagnostic complexes. This transition is demonstrated to significantly enhance both the operational efficiency (responsiveness) and the reliability (accuracy) of testing procedures. Critical zones within the wheel disc susceptible to stress generation under the influence of vertical (normal) and lateral (horizontal) force loadings have been definitively identified and mapped. An optimized, scientifically validated scheme for the strategic placement of strain gauges (tensometric sensors) is proposed to ensure high-fidelity determination of wheel-rail contact forces. The study culminates in the formulation of universal, comprehensive technical specifications and requirements for mobile measurement systems. These systems are specifically engineered for the operational monitoring of freight wagon running quality during active revenue service, as well as during critical commissioning and acceptance testing phases required for authorizing new wagons onto public infrastructure. The proposed integrated measurement system has undergone successful field-testing and validation under real-world operational conditions simulating typical freight wagon usage. The empirical results and specifications obtained enable the precise definition of core technical parameters necessary for the development and deployment of effective mobile diagnostic complexes. These data sets hold considerable weight and are fundamentally important in the engineering design process of advanced monitoring systems destined for railway transport applications. Such systems are intrinsically oriented towards rigorous safety assessment, achieved through the continuous, real-time monitoring of structural health (condition) and dynamic running behaviour. The practical implementation of the proposed methodologies and systems is projected to directly and materially contribute to the reduction of accident risks across railway networks, thereby enhancing overall operational safety