Results in rail research using SIMPACK Politecnico di Torino - Dip. di Meccanica IIa Facoltà di Ingegneria (Vercelli) N. Bosso, A. Gugliotta, A. Somà
The railway dynamic research group of the Mechanical Department of the Politecnico of Torino mainly direct its activities to carry out studies on the dynamic behaviour on railway vehicles in order to analyse stability and safety of rolling stock, using Multibody simulation codes. Politecnico di Torino - N. Bosso, A. Gugliotta, A. Somà 2/24
The behaviour of light rail vehicles during curving is analysed. Different bogie types are compared. Particular attention is given to the understanding of the influence of different traction systems and of the disposition of the traction bogie in the vehicle. Politecnico di Torino - N. Bosso, A. Gugliotta, A. Somà 3/24
E C I C I C E B1 B2 B3 2 External Coaches 3 small connecting Coaches 2 Internal Coaches (E) (C) (I) B2 B1 BOGIE B1 B2 B3 B2 B1 CONFIGURATION 1 TRACTIVE CARRIED CARRIED CARRIED TRACTIVE 2 CARRIED TRACTIVE CARRIED TRACTIVE CARRIED Politecnico di Torino - N. Bosso, A. Gugliotta, A. Somà 4/24
UPPER CONNECTION : SEE DETAIL SPHERICAL REVOLUTE BOLSTER SECONDARY SUSPENSION UPPER CONNECTION Coach connections : Lower : spherical joint (rigid) Upper : connecting rod (elastic) Bolster -Coach connection : Revolute joint (rigid) Politecnico di Torino - N. Bosso, A. Gugliotta, A. Somà 5/24
Different Bogie type have been considered : Conventional Bogie - both wheelset traction Conventional Bogie - No traction Articulated Bogie - Motor wheels Articulated Bogie - Side traction Articulated Bogie - No traction Politecnico di Torino - N. Bosso, A. Gugliotta, A. Somà 6/24
Rigid Bogie Frame Rigid Wheelset Elastic primary suspension between frame and axle box. Secondary suspension between frame and bolster : 2 Air Spring 2 Lateral Bumpstop 1 Anti - Roll bar 2 Traction rod Bolster Air spring Bogie frame Politecnico di Torino - N. Bosso, A. Gugliotta, A. Somà 7/24
Bogie frame divided in two rigid body Elastic element connecting the two frame No primary suspension Independent wheels Secondary suspension : 4 air spring 1 Antiroll-bar 2 Lateral bumpstop 2 traction rod y x y x y x Politecnico di Torino - N. Bosso, A. Gugliotta, A. Somà 8/24
Air Spring support Bushing Type Elastic Element Wheel axle / Rigid connection (Revolute) Politecnico di Torino - N. Bosso, A. Gugliotta, A. Somà 9/24
The articulated bogie has been created in different variants: trailing bogie motor wheels: each wheel is motorised. side traction: One motor is present in each side of the bogie frame, connected to the two wheels of the same side with an elastic joint. The motor characteristic is given by a constant torque up to the nominal speed followed by a constant power behaviour. The overall power is the same for each motorised bogie Politecnico di Torino - N. Bosso, A. Gugliotta, A. Somà 10/24
Wheel Profile : UNI 3322 Rail Profile : UNI 3142 Profiles have been realised using the wheel/rail profile approximation tool of SIMPACK. The track used for the simulation is composed by a straight section followed by a transition curve and finally a curve section of different radius (15-50 -100 m). Politecnico di Torino - N. Bosso, A. Gugliotta, A. Somà 11/24
Rigid coaches and bogie frames Linear elastic elements No dampers Simplified air spring model : constant stiffness and constant preload. No track irregularity Politecnico di Torino - N. Bosso, A. Gugliotta, A. Somà 12/24
Comparison of different contact models : rigid one point contact. 3 point contact. elastic contact. Comparison of different bogie type Influence of bogie disposition Politecnico di Torino - N. Bosso, A. Gugliotta, A. Somà 13/24
Y Displacement [m] Rigid contact 3p Contact Elastic Contact 3.00E-03 3.00E-03 1.50E-02 2.00E-03 2.00E-03 1.00E-02 1.00E-03 0.00E+00-1.00E-03 0 10 20 30 40 1.00E-03 0.00E+00-1.00E-03 0 10 20 30 40 5.00E-03 0.00E+00-5.00E-03-1.00E-02 0 10 20 30 40-2.00E-03-2.00E-03-1.50E-02-3.00E-03-3.00E-03-2.00E-02 Front wheelset Rear wheelset Politecnico di Torino - N. Bosso, A. Gugliotta, A. Somà 14/24
X Friction Force [N] Rigid contact 3p Contact Elastic Contact 2.00E+03 2.00E+03 1.00E+04 1.50E+03 1.50E+03 8.00E+03 1.00E+03 1.00E+03 6.00E+03 4.00E+03 5.00E+02 5.00E+02 2.00E+03 0.00E+00 0.00E+00 0.00E+00-5.00E+02 0 10 20 30 40-5.00E+02 0 10 20 30 40-2.00E+03 0 10 20 30 40-1.00E+03-1.00E+03-4.00E+03-6.00E+03-1.50E+03-1.50E+03-8.00E+03-2.00E+03-2.00E+03-1.00E+04 Wheel Front Left Wheel Rear Left Wheel Front Right Wheel Rear Right Politecnico di Torino - N. Bosso, A. Gugliotta, A. Somà 15/24
3 point contact model and rigid contact give similar Y displacement and yaw angle for the wheelsets (difference < 2%). Elastic contact shows numerical problems : higher displacements, higher forces especially when entering the curve. 3 point contact gives higher friction forces in the first part of the curve (when flange contact occur). The lower computational time is obtained with the rigid contact model, while the 3 point contact lead to computational time up to 4 time higher. The 3 point contact model seems to be the more accurate, however due to the higher simulation time required the simulation on the entire vehicle have been performed using the rigid contact model. Politecnico di Torino - N. Bosso, A. Gugliotta, A. Somà 16/24
Y Lateral Displacement - First Bogie 0,003 0,002 0,001 0 0 5 10 15 20 25 30 35 40 45 50-0,001 Conventional Bogie -0,002-0,003 0,003 0,002 0,001 0 0 5 10 15 20 25 30 35 40-0,001-0,002 Articulated Bogie Side traction -0,003 0,004 0,003 0,002 0,001 0 0-0,001 5 10 15 20 25 30 35 40-0,002 Articulated Bogie Motor wheels -0,003-0,004 Politecnico di Torino - N. Bosso, A. Gugliotta, A. Somà 17/24
Constraint Forces [N] - First Bogie Conventional Bogie 1,00E+04 Articulated Bogie - side traction 5,00E+03 Articulated Bogie - motorwheels 5,00E+03 5,00E+03 0,00E+00 10 20 30 40 50-5,00E+03-1,00E+04-1,50E+04-2,00E+04-2,50E+04-3,00E+04 0,00E+00 10 15 20 25 30 35 40-5,00E+03-1,00E+04-1,50E+04-2,00E+04-2,50E+04-3,00E+04 0,00E+00 10 15 20 25 30 35 40-5,00E+03-1,00E+04-1,50E+04-2,00E+04-2,50E+04-3,00E+04 X -Friction Forces [N] - First Bogie 8,00E+03 6,00E+03 4,00E+03 2,00E+03 0,00E+00 0 10 20 30 40 50-2,00E+03-4,00E+03-6,00E+03-8,00E+03 1,00E+04 8,00E+03 6,00E+03 4,00E+03 2,00E+03 0,00E+00 0-2,00E+03 10 20 30 40-4,00E+03-6,00E+03-8,00E+03-1,00E+04 8,00E+03 6,00E+03 4,00E+03 2,00E+03 0,00E+00 0 10 20 30 40-2,00E+03-4,00E+03-6,00E+03-8,00E+03-1,00E+04 Politecnico di Torino - N. Bosso, A. Gugliotta, A. Somà 18/24
Traction joint torque [Nm] Traction bogie 1-5 Traction bogie 2-4 8,00E+02 6,00E+02 4,00E+02 2,00E+02 0,00E+00-2,00E+02-4,00E+02-6,00E+02-8,00E+02 0 5 10 15 20 25 30 35 40 Left side - Front Left side - Rear 2,50E+03 2,00E+03 1,50E+03 1,00E+03 5,00E+02 0,00E+00-5,00E+02-1,00E+03-1,50E+03-2,00E+03-2,50E+03 0 5 10 15 20 25 30 35 40 Right side - Front Right side - Rear Politecnico di Torino - N. Bosso, A. Gugliotta, A. Somà 19/24
The conventional bogie shows an high instability in the longitudinal direction, due to the presence of only 2 airsprings. Lateral displacement is similar for all bogies, the lower is obtained with the side traction bogie. Friction and constrain forces are lower in the motor-wheel model, while with the side-traction bogie some wheels are unloaded. The side traction bogie leads to high torque in the transmission joint during curving. Politecnico di Torino - N. Bosso, A. Gugliotta, A. Somà 20/24
Influence of Disposition Articulated bogie - Motorwheels (2nd bogie) Case 1 ( Traction 1-5) Case 2 (Traction 2-4) Y Displacement [m] 4,00E-03 3,00E-03 2,00E-03 1,00E-03 0,00E+00-1,00E-03-2,00E-03-3,00E-03-4,00E-03 0 5 10 15 20 25 30 35 40 1,40E-02 1,20E-02 1,00E-02 8,00E-03 6,00E-03 4,00E-03 2,00E-03 0,00E+00-2,00E-03-4,00E-03 0 5 10 15 20 25 30 35 40 Normal Load [N] 0-5000 -10000-15000 -20000-25000 -30000-35000 -40000 0 10 20 30 40 50 20000 10000 0-10000 -20000-30000 -40000-50000 0 10 20 30 40 50 Politecnico di Torino - N. Bosso, A. Gugliotta, A. Somà 21/24
Influence of Disposition Articulated bogie - side traction (2nd bogie) Case 1 ( Traction 1-5) Case 2 (Traction 2-4) Y Displacement [m] 1,20E-02 1,00E-02 8,00E-03 6,00E-03 4,00E-03 2,00E-03 0,00E+00-2,00E-03-4,00E-03 0 5 10 15 20 25 30 35 40 1,20E-02 1,00E-02 8,00E-03 6,00E-03 4,00E-03 2,00E-03 0,00E+00-2,00E-03-4,00E-03 0 5 10 15 20 25 30 35 40 20000 30000 Normal Load [N] 10000 0-10000 -20000-30000 -40000-50000 0 10 20 30 40 50 20000 10000 0-10000 0 10 20 30 40 50-20000 -30000-40000 -50000-60000 Politecnico di Torino - N. Bosso, A. Gugliotta, A. Somà 22/24
The better disposition obtained is the one with motor in the first and the last bogie. The higer influence of disposition is noticeable on the motor - wheel bogie (wheel unloading appear on the 2nd bogie). The side traction bogie shows unloading in both disposition. Politecnico di Torino - N. Bosso, A. Gugliotta, A. Somà 23/24
Comfort study : Introduction of body flexibility Introduction of dampers detailed air-spring model Introduction of an intelligent motor wheel control loop. Lower contact forces Self steering capability Politecnico di Torino - N. Bosso, A. Gugliotta, A. Somà 24/24