An Investigation into the Modeling Methodology of the Coil Spring

Abstract

The coil spring is an important element in the suspension system of railway vehicles, and its structural vibration caused by the mass distribution can deteriorate the dynamic performance of the vehicle. However, the coil spring is usually modelled as a simple linear force element without considering the dynamic characteristics in multibody dynamic simulations of railway vehicles. To integrate the dynamic characteristics of the coil spring into the simulation, three equivalent dynamic models of the coil spring are established by treating the coil spring as multimass spring series, Timoshenko beam, and flexible spring, respectively. The frequency-sweep method is applied to obtain the dynamic response of the proposed models of coil spring, and the accuracy of the models’ results has been compared and verified by the laboratory test. Results show that all of these three equivalent models can reflect the influence of the spring mass distribution on its dynamic responses. Compared with the mass-spring series and beam element equivalent models, the flexible spring model can better reflect the dynamic stiffness and stress of the coil spring changing with the exciting frequency. Thus, the flexible spring model proposed in this paper is more applicable to railway vehicle system dynamics and the fatigue analysis.

Optimization of suspension of rail vehicles with coil springs using marine predators algorithm

“…Orlova et al 5 have studied the usage of the method of finite elements (FEM) in determining the stress and structural strength of the coil spring for suspension of rail vehicles. Dai et al 6 have investigated new techniques for modeling the coil springs and proposed a new flexible model of spring that is more suitable for analyzing the dynamic performances of rail vehicles. The static analysis of the coil spring of primary suspension of the locomotive and the improvement of its strength by introducing new material, has been studied by Kumar et al 7 The method of dynamic matrix of stiffness has been applied for determining the coil spring dynamic stiffness in the primary suspension of railway vehicle by Sun et al 8 Kumbhalkar et al 9 and Reddy and Reddy 10 have investigated the failure of coil springs of railway vehicles taking into account material properties and types of loading.…”

Wet Friction of Rubbers Containing DAE or TDAE Process Oil in ESBR and ESBR/BR Blends

“…Keeping it in mind, Bowman et al employed an "iso-T g " concept and developed a type of ESBR having styrene content higher than the commercial grades, which could present a higher compensating T g when it is utilized in formulations containing mildly extracted solvate (MES) or treated distillate aromatic extract (TDAE) oils. [7] Other researchers prefer to compare the values of loss tangent at the common temperature of "zero" to find out the desired oil in terms of the frictional properties. [8][9][10] However, it must not be forgotten that choosing the temperature of zero as a point of comparison is based on several assumptions that have to be preliminarily met.…”

In situ and experimental analysis of longitudinal load on carbody fatigue life using nonlinear damage accumulation

“…A vehicle loading structure's fatigue strength has a significant effect on its stability, so it must be considered. In last decades (Amitesh et al., 2016; Dai et al., 2020; Sun et al., 2020), many fatigue strength measurement techniques for rail vehicles have been proposed including fatigue analysis for uniform loading by the endurance limit, analysis of fatigue test programs by cumulative damage, and analysis of simulated multiple body systems by cumulative damage. These techniques have been widely used by railway organizations (Palli et al., 2018; Sharma and Kumar, 2018; Sharma et al., 2020; Sharma and Sharma, 2018).…”