汽车底盘零部件CAE.ppt

汽车底盘零部件CAE分析Structural Analysis Capabilities§Normal Modes§Dynamic§Linear & Nonlinear Static§Buckling§Fatigue§CrashworthinessExamples:Base 4-Link Lower Control Arm→ 3,2 kg 56 kN/mm stiffness61 kN bucklingthickness:2,5 mmmaterial:S 355 MC≤ 2,4 kg (low weight)≤ 3,2 kg (cost optimized)> 50 kN/mm stiffness> 35 kN bucklingBoundary conditions Stiffness / BucklingStress analysisConstrained indof 1-3Constrained indof 2-4Forces and / or MomentsLateral ForceAccelerationBrakingCornerBase 4-Link Trailing Arm/ Wheel Carrier≤ 5,4 kg (low weight)≤ 6,2 kg (cost optimized)→ 6,9 kgBoundary conditions StiffnessStress analyseConstrained indof 1-3Constrained indof 2Constrained indof 2Constrained indof 2-3Forces and / or Moments647 MPa579 MPaCornerVertical ForceBase 4-Link Upper Control Arm≤ 2,1 kg (low weight)≤ 2,7 kg (cost optimized)> 30 kN/mm stiffness> 20 kN buckling→ 1,94 kg 28 kN/mm stiffness27 kN bucklingthickness:3,0 mm shell2,0 mm bushingmaterial:S 355 MCBoundary conditions Stiffness / BucklingStress analysisConstrained indof 1-3Constrained indof 2-4Forces and / or MomentsCalculated with linear elastic behavior of the material561 MPaPotholeTwistBase 4-Link Additional Control Arm≤ 0,28 kg (low weight)≤ 0,36 kg (cost optimized)> 100 kN/mm stiffness> 39 kN buckling→ 0,34 kg 177 kN/mm stiffness38,6 kN bucklingthickness:1,5 mm material:S 355 MCCalculated with linear elastic behavior of the material694 MPaPotholeCorner turnBoundary conditions Stiffness / BucklingStress analysisConstrained indof 1-3Constrained indof 2-4Forces and / or Moments≤ 1,3 kg (low weight)≤ 1,7 kg (cost optimized)> 25 kN/mm stiffness x> 15 kN/mm stiffness yBase 4-Link Bracket→ 1,23 kg33 kN/mm stiffness x50 kN/mm stiffness ythickness:4,0 mm material:S 355 MCBoundary conditions Stiffness / BucklingStress analyseConstrained indof 1-6Constrained indof 1-6Forces and / or MomentsConstrained indof 1-6Constrained indof 1-6CornerBrakingUplevel H-Arm Lower Control Arm ≤ 6,8 kg (low weight)≤ 9,5 kg (cost optimized)→ 8,74 kg thickness:3 mm upper shell 2,5 mm lower shellmaterial:S 420 MC upper shellS 355 MC lower shellBoundary conditions StiffnessStress analysisConstrained indof 3Constrained indof 3Forces and / or MomentsConstrained indof 2-3Constrained indof 1-3Longitudinal ForceLateral ForceBrakingValidation RequirementsFront Suspension Lower Control ArmsMethod for Computing Static Stiffness (Front Lower Control Arm):§Reported at ball joint center at x- and y-direction§between two connection pointsFor All Cradles:§Report at all bushing and ball joint centers§Steering stiffness shall be computed at the tie-relay ball with a rigid bodyFor Non-Isolated Cradles:§Steering should be attached rigid to the crossmember§Front crossmember to body interface center points should be pinned to ground allowing rotation about the (X,Y,Z) axis and no translation from these pointsFor Isolated Cradles:§Use GM Cradle on Mount Differential Stiffness Method with bushing rates (x=2KN/mm, y=2KN/mm, z=2KN/mm)§Use steering bushing rates (x=10KN/mm, y=10KN/mm, z=1KN/mm).§First calculation with an elastic cradle, second with a rigid cradle. Subtract the two displacements and calculate the stiffness.Validation RequirementsFront Suspension CrossmembersMethod for Computing Static Stiffness:DOF (1,2,3) lockedTOTAL MASS =21.85 Kg. Lateral Tubes [ 2.6mm DP500 ]Front Tube[ 2.25mm DP500 ]Fr. Control Arm brackets[ 3mm HR60 ]Attachments to Body[ 3.2mm stw22 ]Upper Crossmember[ 2.5mm HSLA 360 ]Lower Crossmember[ 2.3mm HSLA 360 ]Engine support Front[ 2.5mm stw22 ]Re. Control Arm support[ 3mm stw22 ]2. FEA Linear Load Cases ResultsREF. 132 190 65Units: MpaStanding Car1GVertical Load3.5GLongitudinal Load 2GLateral Load2GAccelerating0.5GBraking1.1GCornering1.2GBraking Turn1.05GFront Tube46.376.8307.217.61.1270.233.264.Lateral Tubes22.064.6385.239.62.2395.246.240.Front Control Arm Bracket24.876.8568.213.96.3694.233.472.Upper Crossmember35.8134.465.334.73.1382.309.396.Lower Crossmember34.9189.530.541.146.493.566.438.Rear Control Arm Bracket11.747.0178.37.941.4255.55.1188.Engine Support Front121.073.1104.178.133.77.1196.80.Engine Support Rear45.673.1314.297.74.9332.328.162.3. FEA Linear Load Cases PlotsLoad Case: 1G Standing CarREF. 132 190 65Load Case: 3.5G Vertical Load3. FEA Linear Load Cases PlotsREF. 132 190 65Load Case: 2G Longitudinal Load3. FEA Linear Load Cases PlotsREF. 132 190 65Load Case: 2G Lateral Load3. FEA Linear Load Cases PlotsREF. 132 190 65Load Case: 0.5G Accelerating3. FEA Linear Load Cases PlotsREF. 132 190 65Load Case: 1.1G Braking3. FEA Linear Load Cases PlotsREF. 132 190 65Load Case: 1.2G Cornering3. FEA Linear Load Cases PlotsREF. 132 190 65Load Case: 1.05G Braking Turn3. FEA Linear Load Cases PlotsREF. 132 190 65Units: KN / mmX DirectionTarget X Dir.Y DirectionTarget Y Dir.Z DirectionTarget Z Dir.Front Control Arm Bracket Left19.945.12.2614.4.065.Front Control Arm Bracket Right.20.205.12.5614.4.295.Rear Control Arm Bracket Left27.7720.59.8820.5.295.Rear Control Arm Bracket Right27.5420.60.9720.5.5.Engine Support Front9.439.5.155.2.013.5Engine Support Rear33.3310.18.115.2.393.5Rack house Mount Left50.7625.55.2425.8.408.Rack house Mount Right48.6825.55.5525.7.468.Stabilizer Bar Mount Left52.6310.34.485.13.4216.Stabilizer Bar Mount Right51.2810.30.585.12.8816.4. Static Stiffness Measurement Non – Isolated BracketsREF. 132 190 65Frequency (Hz.)DescriptionMode 1 to 60.Rigid Body MovesMode 793.2First Torsion ModeMode 8153.85-Mode 9169.86First Crossmember bending ModeMode 10253.65First Lateral Tubes bending ModeMode 11321.0-Mode 12329.9-Mode 13366.9-6. Modal Analysis FREE – FREE ConfigurationREF. 132 190 65Thank you!。