Analysis of Front Suspension Lower Control Arm of anAutomobile Vehicle

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International Journal of  Science and Research (IJSR) 

ISSN (Online): 2319‐7064 

 

Figure 5: Control Arm Sections

5.2 FE Model

Import the IGS file to Hypermesh and clean up the

geometry. In meshing trias at straight pillets are avoided andeven at the critical location such as notches, holes, slots and

sudden geometric changes. Here shell meshing is made atcontrol arm and reinforcement material. In shell meshing

triangular and quadrilateral elements are used. At ball joint,front and rear bushing solid meshing are made. At ball joint

RB2 element and at front and rear bushing RB3 element areused. While meshing 20000 elements are used in shell

meshing. Two RB3 elements and one RB2 elements are usedin front and back bushing and ball joint respectively.

5.3 Boundary Condition

Figure 6: Boundary Condition for Stiffness

Each link has 6 degrees of freedom. 3 translation motion and

Figure 7: Boundary Condition for Stress and Buckling Case

For stress and buckling analysis boundary conditions at thefront and rear bushing is grounded condition [one end of the bushing is grounded and other end connected the RBE3

element}

5.4 Original Equipment Manufacturer Constraints

  Mass: ≤ 2.2 kg

  Stiffness X: ≥ 3 KN/mm

  Stiffness Y: ≥25 KN/mm

  Permanent set: ≤ 1 mm

  Bucking Load : ≥ 28 KN

6. Analysis

6.1 Stress Analysis

Fig 7 shows the stress distribution in forward case. The

maximum stress is 126 MPa and minimum stress in the

component is 10 MPa.

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Each link has 6 degrees of freedom. 3 translation motion and3 rotation motion, for stiffness analysis front bushingtranslation motion in x, y and z direction are fixed. Whereas

in rear bush, translation motion in y and z direction arefixed. At ball joint z direction motion is fixed. For other

analysis like stress, buckling and permanent set all sixmotion in front and rear bushing are fixed and at ball jointtranslation motion in z direction is fixed. Figure 8: Stress Analysis Forward case

Fig 8 shows the stress distribution in backward loading. Themaximum stress is 365 MPa and minimum stress in thecomponent is 29 MPa.

Paper ID: 01101302 53

 

International Journal of  Science and Research (IJSR) 

ISSN (Online): 2319‐7064 

 

Figure 9: Stress Analysis Rearward case

Fig 9 shows the stress distribution for inward loading. The

maximum stress is 187 MPa and minimum stress in thecomponent is 24 MPa.

Figure 10: Stress analysis inward case

Fig 10 shows the stress distribution for outward loading. The

maximum stress is 45 MPa and minimum stress in thecomponent is 5 MPa.

6.2 Stiffness Analysis

Stiffness boundary condition is shown in fig. 5. Stiffness iscalculated for longitudinal and lateral case. 1000 N Load isapplied in ball joint for both longitudinal and lateral case. InHyperview magnitude of displacement is noted. Stiffness is

calculated by

X-stiffness= x-load/x-displacementY-stiffness= y-load/y-displacement

Table 2: Shows the Stiffness Of Control Arm

Stiffness EAR-rein-1.8 mm EAR-rein-2 mm

KN/mm KN/mmLongitudinal 6.9 7.1

Lateral 35.5 36.5 Initially for 1.8 mm thickness stiffness is calculated. As 1.8mm thickness is not reach the buckling target. So,commercially available sheet metal of thickness 2 mm was

chosen and result of analysis for both the cases are tabulatedin table 2.

6.3 Buckling Analysis

For buckling, displacement control approach is adopted to

find the buckling load. In this approach displacement isgiven at the ball joint for check the load. When increasing

the displacement, load increases.

Figure 12: Buckling analysis

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Figure 11: Stress analysis outward case

The yield stress of the JSH 590B is 440MPa. By the stressanalysis results it is clear that all the stresses exerted arewithin the yield stress. Maximum stress exerted in forwardcase is 126MPa. In backward case is 365MPa. Maximumstress exerted in inward case is 187MPa. Maximum stress

exerted in outward case is 45MPa. It is very clear thatmaterial satisfies all stress condition.

Figure 13: Force vs. displacement to find the buckling load

Graph is plotted for displacement vs. load. Buckling analysisis to find the maximum buckling load. From fig 11 for 29

Paper ID: 01101302 54

 

International Journal of  Science and Research (IJSR) 

ISSN (Online): 2319‐7064 

mm displacement component buckles. From the fig 42

maximum buckling loads that control arm can take is 30KN.

6.4 Permanent Set Analysis

This is a nonlinear analysis. Force control approach is

 

adopted to know the permanent displacement at the ball joint. It is assumed that 25 KN is the maximum elasto plastic

load. 27 kN load is applied and sudden unloaded to know the permanent deformation.

Figure 14: Load Applied In Elasto Plastic Region

Figure 15: Load Removed From Elasto Plastic Region

Load Vs Displacement is plotted to find the permanent set.

Fig 15 shows the permanent deformation in the ball joint,that is 0.8 mm.

7. Results and Discussion

7.1 Stress Results

Stress analysis is made for various load cases. For forward

case 2650 N is applied. And for backward case 7660 N andfor outward case 1700 N and for inward 7070 N load are

applied on the basis of OEM constrains.

Table 3: Stress Analysis Results

Particular Load applied In N Maximum stress exerted In MPa

Forward 2650 126

Backward 7660 365

Inward 7070 187

Outward 1700 45

It is revealed from the numerical stress analysis data shownin table 2 that the front suspension lower control arm willmeet the specification of OEM constraints in all the 4different loading condition. By reference, yield stress of JSH590B is 440 MPa. In the present analysis stresses with

respect to forward, backward, inward and outward stressesare well within the yield stress of the material and it is alsofound that stress is more in backward load condition and

least in outward loading condition.

7.2 Stiffness Results

Table 4: Stiffness Analysis Result

Stiffness

 EAR-rein-

1.8 mm

 AR-rein-2

mm

OEM

Constraints

3 KN/mmKN/mm KN/mm

Longitudinal (X-Stiffness) 6.9 7.1 ≥ 3 KN/mm

Lateral (Y-Stiffness) 35.5 36.5 ≥25 KN/mm

 It is been found by the stiffness analysis results shown in the

table 3 that the specified material for front suspension lowercontrol arm will satisfies the OEM constraints; that is,stiffness in the lateral direction greater than or equal to 25KN/mm and in longitudinal direction greater than or equal 3KN/mm at a minimum reinforcement thickness of 1.8 mm.But at this particular thickness, buckling load constraints arenot satisfied. Hence the material with 2 mm thickness

 prepared as it satisfies non linear cases.

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that is 0.8 mm.

Figure 16: Force vs. Displacement to Check Permanent

Deformation

The comparison between specified material andcommercially used materials like FB 560 and FB 590 hasshown that all the above material will meet the OEM targetfor leaner analysis at 3 mm thickness. But only JSH 590Bwill sustain non linear cases.

7.3 Buckling Results

The displacement Vs force plot clearly illustrates the buckling load for the different material with regards to OEMconstraints. At 3 mm thickness JSH 590B is having themaximum buckling load of 30 KN whereas FB 560 and FB

590 materials will buckle at fewer loads as shown in the fig16. However FB 590 material closely approaches the targetwith a buckling load of 28 KN.

Paper ID: 01101302 55

 

International Journal of  Science and Research (IJSR) 

ISSN (Online): 2319‐7064 

 

Figure 17: Force vs. displacement curve

Table 5: Material Composition Material C % Mn % Si % Remaining

FB560 0.08 1.5 0.12 Steel

FB590 0.1 1.6 0.15 SteelJSH590B 0.2 2.3 1.20 Steel

By analyzing chemicals of 3 preferable materials it is clearthat JSH 590B stands tougher, ductile, stronger due to theincrease in percentage of silicon, manganese and carbonrespectively. And increased carbon content yields in greaterstrength achievement by the material but it also increases the

material cost. Using JSH 590B can saves the material ofthickness of 1 mm compare to FB 560 and FB 590. Thisreduced thickness may compensate the cost.

7.4 Permanent Set

The OEM constraints for permanent set is less than or equalto 1 mm. JSH 590B material shows the permanent set of

0.88 mm shown in fig. 14 for 3 mm control arm. But FB 560and FB 590 are not within this target. 

8. Conclusions

From the present simulation on front suspension lower

manufacturing front suspension lower control arm of anautomobile vehicle as it shows better mechanical properties as compare to the presently used materials.

References

[1] Don knowles. Automotive Suspension & Steering

System. Cengage Learning, 2006 ,[2] Jain, K.K., R.B. Asthana. Automobile Engineering.

London: Tata McGraw-Hill,[3] Kawasaki steel technical report No. 48 March 2003,[4]  Nastran, Hypermesh and Abaqus Manuals.

Author Profile

Nithin Kumar  received B. E degree in Mechanical

Engineering from Shiradi Sai Engineering College,Bangalore in the year 2008. He obtained his Master’s

Degree in the area of “Machine Design” in UVCE,Bangalore in 2010. He has 03 years of teaching

experience and currently working as assistant professor in the

department of mechanical engineering, NMAMIT, Nitte

Veeresha R K  received B. E degree in MechanicalEngineering from STJIT, Ranebennur in the year

2007. He obtained his Master’s Degree in the area of“Design Engineering” in JNNCE, Shivamogga in

2010. He has 03 years of teaching experience andcurrently working as assistant professor in the department ofmechanical engineering, NMAMIT, Nitte 

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Volume 2 Issue 10, October 2013

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control arm made up of JSH 590B material followingconclusions can be made.

  JSH 590B material used in the analysis will satisfy all the

OEM specifications.

  In the stress analysis the material stress for differentloading conditions, will fall well within the yield stress.

Forward 126 N, Backward65 N, Inward187 NandOutward45 N.

  This material satisfies stiffness constraints at 2 mmthickness of reinforcementi. E-Longitudinal (X-Stiffness)6.9 kN/m and Lateral stiffness (Y-direction) 36. kN/m.

  JSH 590B exhibits maximum buckling load of 30 KN,

which is higher than OEM constraint parameter.

  Chemical composition of the material is also better, whichimparts higher ductility, toughness and strength of the

component.

  It also satisfies permanent deformation parameter for the permanent set i.e less than 1 mm.

  Therefore the material JSH 590B can preferably used asthe better substitute for the manufacturer for

Paper ID: 01101302 56