Dynamical Deflection Analysis Of 370t Center-depressed Flatcar Based On Rigid-flexible Coupling

With the rapid development of national economy, more and more ultra big and the overload foundation equipment increases in the trades, such as large-scale machine manufacture, aerospace, chemical and nuclear industry and so on. In order to meet the need of freight, a factory developed 370t center-depressed flatcar which is the biggest domestic load-carrying capacity, the maximum load bearing surfaces and the smallest dead weight coefficient in the great tonnage center-depressed flatcar. The full vehicle is composed of 1 center-depressed flat-frame,2 super-frames,4 infra-frames and 8 3E-axle bogies. It uses 3 kinds of guiding manners:inner-guiding, mid-guiding and out-guiding.Because the vehicle is the big load-carrying capacity and the big concave bottom structure size, as the center-depressed flat-frame with carrying cargo, the deflection-span ratio is only required to achieve 1/150, however, the heavy vehicle track surface high is only 120mm, therefore, the paper proposes the problem of the invasion of the lower bound track surface. Well, the problem of the invasion of the lower bound track surface determines the bottom of center-depressed flat-frame (or the bottom of the flatcar) to contact with the surface of the rail or not in consideration of center-depressed flat-frame, super-frames and infra-frames 7 structure dynamic deflection conditions. Because the static deflection of the center-depressed flat-frame achieves 230mm, it is formed the transition from the initial state to the balance state (as for the initial state stable equilibrium problems). Well, the convergence methodology of quasi-equilibrium is proposed with large structural damping in the paper based on the flexible body restraint characteristic, and the relative error of the quasi-static deflection of laden center-depressed flat-frame is reached to 3.2%. Besides, as the extension of experimental technique, the twisting deformation (0.26-0.31) deg of the super-frame can be obtained further from the multi-simulation contrast of various Rigid-flexible coupling modes under such serious bias load as the 500mm lateral displacement of the 370t laden flatcar.The low-velocity simulation comparison of small radius curve negotiation shows that the inner-guiding curve negotiation of minimum radius R300m should be taken as the dangerous operating condition of minimum high from the track surface. According to the beneficial influence of superelevation to the flatcar bottom raised from rail surface, it is advised that the suitable superelevation (20-30) mm is necessary in the minimum radius curve negotiation. The following conclusions are confirmed in many normal line running simulations:due to the huge mass and inertia moment of laden center-depressed flatcar, the strong displacement vibration is not possible to be produced in the flatcar bottom. Through the safety analysis of the load small radius curve and S curve, the stability evaluation indexes, such as derailment coefficient, wheel unloading rate and lateral wheelset force and so on, nearly meet the requirement of the GB5599-85. According to the structural design features of "the big corner" of the center-depressed flat-frame, the structural dynamic stress analysis shows the necessary of local high stress area for monitoring.In the dynamical simulation analysis of DA37 Center-depressed flatcar, Some novel technologies are applied in the paper, as follows:(1) Rigid-flexible coupling simulation analysis based on the multi-flexible bodies; (2) The proposal of the convergence methodology in large structural damping; (3)The introduction of vehicles and buildings limit boundary.