Design & Simulation of one axle trailer loading by 6 or 7 passenger cars - Virtual Product Development Jaroslav Maly & team CAE departament www.aveng.com
Pro/ENGINEER design optimization of axle trailer was integrated with Vehicle dynamic & linear FEA simulations. The design is limited for loading 6 or 7 passenger cars and EU standards for trailer vehicles.. DESIGN TARGETS Loading by 6 cars Peugeot 45 Loading by 7 cars Peugeot 26
The design of trailer was prepared for defined truck, king pin, axle and hydraulics jack. DESIGN RESTRICTION Model: Type: Type of cars : Cab : Power of engine: Wheelbase : Total weight : Mercedes-Benz Actros 1843 LS Tractor S-Cab 315 kw (428PS) 36 mm 18 kg
The vehicle dynamic was used as a tool for setting the loading condition for linear FEA simulation. The tire model AVTirEng was implemented to the vehicle dynamic simulation. Tire characteristic: AVTirEng model Tire vertical stiffness [N/mm] Tire vertical damping [Ns/mm] Rolling resistance [-] Wheel load capacity [N] Slip max [-] Slip-stick ratio[-] Cornering stiffness [N/-] Static friction coefficient [-] Pin VEHICLE DYNAMICS MODEL z Yaw x Roll CG Trailer center of gravity (7 cars Peugeot 26) (6 cars Peugeot 45) Mass = [kg] Moments of inertia: Ixx = [t*mm2] Iyy = [t*mm2] Izz = [t*mm2] y Pitch Front Axle Rear Axle Tractor MB 1843LS Wheelbase 36 mm Chassis weight 648 kg Damper Spring Trailer Axle Frame
Deceleration 1.33 ms-2 Initial condition 8 km/h Full brake VEHICLE DYNAMICS - BRAKING Wheel Load Pitch Angle.5 8.4 Pitch Angle [deg].3.2.1.5 1 1.5 2 2.5 -.1 Pitch Moment 3.E+8 Pitch Angle Wheel Load [N] 7 6 5 4 3 2 front left front right rear left rear right trailer left trailer right Pitch Moment [Nmm] 2.5E+8 2.E+8 1.5E+8 1.E+8 Pitch Moment 1.5 1 1.5 2 2.5 5.E+7.E+.5 1 1.5 2 2.5
Turn radius 12 m Speed up VEHICLE DYNAMICS - TURNING Roll Angle Wheel Load Roll Angle [deg] 25 2 15 1 Roll Angle 8 7 6 5 5 1 15 2 25 Velocity [km/h] Roll Moment 1.4E+8 1.2E+8 Wheel Load [N] 5 4 3 2 front left front right rear left rear right trailer left trailer right Roll Moment [Nmm] 1.E+8 8.E+7 6.E+7 4.E+7 2.E+7 Roll Moment 1-1 5 1 15 2 25.E+ 5 1 15 2 25 Velocity [km/h] Velocity [km/h] 19.3 km/h Release of inner wheels
Drive direction Velocity 8 km/h 8 mm VEHICLE DYNAMICS - BUMP 2 5 mm 8 mm.6 Pitch Angle Wheel Load Pitch Angle [deg].5.4.3.2.1 1 2 3 4 -.1 Pitch Angle 1 8 -.2 -.3 -.4 5.E+8 4.E+8 3.E+8 Pitch Moment Wheel Load [N] 6 4 2 front left front right rear left rear right trailer left trailer right Pitch Moment [Nmm] 2.E+8 1.E+8.E+ 1 2 3 4-1.E+8 Pitch Moment.5 1 1.5 2 2.5 3 3.5 4-2.E+8-3.E+8-4.E+8-2
1,5 m VEHICLE DYNAMICS - MOOSE TEST Velocity 5 km/h 15 m Roll Angle Wheel Load 8 6 9 4 Roll Angle [deg] 2 2 4 6 8 1-2 -4-6 -8-1 Roll Moment 1.5E+8 1.E+8 Roll Moment [Nmm] 5.E+7.E+ 2 4 6 8 1-5.E+7-1.E+8 Roll Angle Roll Moment Wheel Load [N] 8 7 6 5 4 3 2 1 2 4 6 8 1 front left front right rear left rear right trailer left trailer right -1.5E+8
Model contains: 76816 elements 73315 nodes FEA MODEL The structural model consists of shell elements (4-noded quads), solid elements (8- nodes brick) and truss elements (2- noded lines). The shell meshes were created on mid surfaces of plates and profiles automatically in Pro/ENGINEER and solids generate manually in MARC pre- and post- processor MENTAT. The truss elements were created by hand in MENTAT. Solids elements are associated to the shell elements by means of element faces. It means the all degree of freedom from shell nodes are translated to solid by 4 nodes. The welds are modelled as a connection associating mid-surface plates. These welds are modelled by shell with equivalent thickness.
FEA MODEL Top floor movement The linear FEA simulation (MSC.MARC) was used for optimization of design and estimation of durability. The loading was realized under vehicle dynamic condition + condition of loading of passenger cars. (floor movement) Tractor support [kn] [kn] Tractor support
Design & Simulation of one axle trailer FEA Results Displacement & Stresses Estimation of Durability LOAD BRAKING Semi-trailer design final Fatigue estimation - Stress range / No. of cycles Node No. Loading weld type Brake 2264 21 186,45,75 8942 97 SKALA 1,, 24959 62 7,243,368 Node No. Loading weld type Turn 2264 8 3,371,674,611 2496 47 SKALA 1,, 24963 37 34,8,852 Node No. Loading weld type Turn 25938 2 215,787,175 2629 38 SKALA 1,, 628 72 4,625,68 Node No. Loading weld type Bump 2264 12 999,14,699 8942 38 SKALA 1,, 24959 25 11,483,34 Node No. Loading weld type Bump 533 73 SKALA 1,, 6473 68 5,49,29 6247 65 6,286,17 LOAD BUMP LOAD TURNING
DESIGN CONCLUSION The optimized design of trailer were prepared as a Virtual Prototype during 3 days. The design satisfy all defined condition & design is prepared for building of physical prototype. VPD Tools for optimization in real development time Used technology: CAD : MBD : Tires : FEA : Durability : Pro/ENGINEER Pro/MECHANICA AVTirEng MSC.MARC SCALA