Multi-Body Simulation of Influence of Bogie Interconnection on Vehicle-track Interaction, VÚKV a.s. Bucharova 1314/8 158 00 Praha 5 krulich@vukv.cz, capek@vukv.cz www.vukv.cz 1
Content Introduction Principal function of bogie interconnection Types under study Dynamic model Effects to lateral suspension Determination bogie interconnection characteristic Influence to reducing lateral wheel forces Conclusions 2
Introduction The purpose of the bogie interconnection is to reduce lateral wheel forces Y The purpose of presented simulations was to evaluate effects of different bogie interconnections types Reduction of lateral wheel forces Y: allows to comply with the standard EN14363 with respect to the maximal permissible lateral force Y allows to operate with higher cant deficiency in track curves positively affects wear of rails and wheels (gives higher safety against derailment) (can give lower tax for use of the railway infrastructure) 3
Principal function Mechanical coupling of bogies by an spring element with appropriate characteristic In track curves the force element acts to each bogie frame by an lateral force H As a result the angels of attack alfa and the lateral wheel forces Y become lower 4
Spring element and its characteristic Spring element is able to transfer forces in both directions Spring is mounted with preload Clearance c enables disconnection of bogies if the vehicle runs in the straight track and/or large radii curves Clearance must by adjusted symmetrical to the position in the straight track, its properly adjustment is enabled by washers 5
Spring element and its characteristic Asymmetrical setting of the spring element: Causes different behaviour for both directions of track radii Causes force peaks if the vehicle runs in the straight track with irregularities due the induced bogie frame movements could lead to running instability 6
Types under study Lateral With torsional rod Hydraulic 7
Types under study Lateral With torsional rod Hydraulic No loco in operation 8
Dynamic model In basic parameters based on 4-axle electric locomotive class 363 operated by ČD Mass: 87 t Bogie pivot distance: 8,3 m Wheelset distance: 3,2 m Wheel diameter: 1,25 m Power: 3480 / 3060 kw Current system: 3 kv / 25 kv 50 Hz Built date: 1981 1987 Total produced: 181 (and other 192 - derived types) 9
Dynamic model Primary suspensions consist of coil springs and hydraulic dampers Wheelsets are guided in the bogie frame by vertical pins In dynamic model simplified by one force element between bogie frame and axlebox 10
Dynamic model Secondary suspensions consist of coil springs and hydraulic dampers Lateral suspension with four long links 11
Dynamic model Lateral bogie interconnection 12
Dynamic model Bogie interconnection with torsional rod (similar to hydraulic interconnection) 13
Effects to lateral suspension Lateral suspension is loaded by Uncompensated lateral acceleration Reaction of different restoring torques of bogies Reaction of bogie interconnection (in the case of connection with torsional rod, hydraulic connection) Dynamic effects (not considered) 14
Effects to lateral suspension 1 Uncompensated lateral acceleration a q acting to carbody mass m cb : Force to lateral suspension F aq = m cb. a q / 2 15
Effects to lateral suspension 2 Reaction force as a result of different restoring torgues of bogies: Different rotation angle of bogies to carbody restoring torques T r2 > T r1 acting to carbody Resultant torque to carbody T r,cb = T r2 T r1 Force to lateral suspension F r = T r,cb / u 16
Effects to lateral suspension 3 Lateral bogie interconnection has no influence to lateral suspension 17
Effects to lateral suspension 4 Reaction forces as a result of the force transfer through the carbody typical of bogie interconnection with torsional rod: F bi = H. t / u 18
Effects to lateral suspension 5 Reaction forces as a result of the force transfer through the carbody typical of hydraulic bogie interconnection: F bi = H. t / u 19
Effects to lateral suspension Summary of all forces acting to lateral suspension (sign + means direction out of the curve) : Rear bogie Front bogie F aq F r F bi F aq F r F bi Lateral connection + - + + Connection with tors. rod + - + + + - Hydraulic connection + - - + + + Connection with torsional rod: negative effects of forces F r and F bi are particullary compensated Hydraulic connection with torsional rod: negative effects of forces F r and F bi are acting in the same direction in front bogie It can exhaust the whole clearance of lateral suspension to its bumpstop 20
Determination of characteristic Determine D = f (H, R) The bogie interconnection is active in track curves radii lower than 800 m Lateral interconnection Interconnection with torsional rod 21
Determination of characteristic Hydraulic interconnection 22
Influence to reducing of lateral wheel forces Y Front bogie: Rear bogie: 23
Conclusions Lateral bogie interconnection: Gives the lowest lateral wheel forces Spring element is placed in the middle of the bogie pivot distance, it gives high displacement enabling properly adjusting Bogie interconnection with torsional rod: Gives much worse results, reduction of lateral wheel forces is very low It is not possible to use the characteristic with higher stiffness because of direct influence on the lateral suspension Displacement in the spring element are lower, more difficult adjustment Hydraulic bogie interconnection: Gives the worst results of all types under study It is not possible to use the characteristic with higher stiffness because of direct influence on the lateral suspension Spring element with very small displacements can not be adjusted 24
Thank you for your attention, VÚKV a.s. Bucharova 1314/8 158 00 Praha 5 krulich@vukv.cz, capek@vukv.cz www.vukv.cz 25