Imperial Journal of Interdisciplinary Research (IJIR) Vol-3, Issue-6, 2017 ISSN: 2454-1362, http://www.onlinejournal.in

Static Structural Analysis and Weight Optimization of Engine Mounting Bracket Using Topology

Diwakar K1, Surendra. A2, Bhaskar. N3 & Mallikarjuna. P4 1Assiatant Professor, Department of Mechanical Engineering, AITS, Kadapa, Andhra Pradesh. 2,3,4Assistant professor, Department of Mechanical Engineering, AITS, YSR kadapa, Andhra Pradesh, INDIA-516003.

Abstract: In the present scenario, the safety of the compartment. Resilient mounting will also provide passengers have become a major concern in the longer life for frame and engine block mounting development of the automotive products Engine brackets, suspended components and transmission by mounting bracket plays an important role in attenuating transient shock inputs and operating automobiles to reduce the vibrations created by the torque loads. Hence optimized structures are need to engine and also it increases the life time of the be designed and fabricated. There are various types engine. In the present study the engine mounting of optimization methods that were developed and bracket of four wheeler of “BEAT CHEVROLET” is have successfully been used in the vehicle structure considered and we can reduce the weight of the design. The design, analysis and optimization of component by using following techniques. The main Automotive Bracket of Engine Mount is discussed objective of the present study is to reduce the weight with dynamic loading under vibration by [1]–[3] of the Engine Mounting Bracket “BEAT using ANSYS software. Furthermore, OptiStruct is CHEVROLET” by using two optimization techniques used for Vibration and Static analysis of Engine (Topology optimization technique and Material Mounting Bracket of TMX 20-2 is investigated by optimization). To develop the 3D model of the Koushik [4]. In the recent past pretension effect of component, the dimensions are taken from the bracket mounting is studied by Maski et al [5] using existing component of “BEAT CHEVROLET” Finite Element Analysis (FEA). However the weight Engine mounting bracket. The model is developed by optimization using Topology Optimization is not yet using the commercial tool of CATIA V5 R20. Then studied. In this context, Carbide the CATIA model is meshed with the help of and 5052 are used as an alternative HYPERMESH and Structural and Modal analysis is materials for Engine Mounting Bracket (EMB). carried out for three different materials (Existing Further optimization is done by using Topology for material: Gray cast iron, Alternative Materials used finding the better material on weight reduction and in this study: Aluminium and structural stability basis. Figure 1shows the location Aluminium alloy 5052) using HYPERWORKS. After of engine mounting bracket in Beat Chevrolet. completion of the analysis of existing model, the optimized model is developed by using topology optimization and the analysis is carried out for the optimized model with the same materials used for existing model. Based on the results in this study, we proposed the best suited model and material for the engine mounting bracket. 1. Introduction During design of vehicle structures, it is always challenging to achieve higher stiffness and strength and simultaneously reduce weight. There are many good reasons to resiliently mount an engine and/or transmission one increasingly important reason is to Figure 1 Location of engine mounting bracket reduce structure bone noise and vibration generated by the engine and transmitted to the vehicles operator

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Imperial Journal of Interdisciplinary Research (IJIR) Vol-3, Issue-6, 2017 ISSN: 2454-1362, http://www.onlinejournal.in

2. Research Methodology PLM(Product Lifecycle Management), Proven openness and standards support. The Engine mounting bracket protects the engine mounting system, which secures the engine and eliminates the brake down of the engine due to vibrations created by the vehicle. It is also used to reduce the vibrations and noise created by the engine, and also it improves the comfort and work environment of a car. In some cases, it may also be an adjustment point to keep a component in proper alignment. Strength Analysis is carried out for three different materials which commonly used for engine mounting bracket in the market. Materials are Gray cast iron (GCI), Aluminum silicon carbide (AlSiC) and Aluminum alloy. In the present study the unit systems are used in the form of density is in ton/mm3, stress is MPa; young’s modulus in MPa. Figure 3 Front part of an EMB and length is in mm, The dimensions are taken from the existing component and the 3D model is developed by using the commercial tool CATIA V5R20. Altair HyperMesh is used for meshing and the boundary conditions materials input and are applied in HyperMesh. By using Radios as a solver, we are solving the linear static and modal analysis is carried out. The methodology used in this study to reduce the weight of the “BEAT CHEVROLET” engine mounting bracket is shown in Figure 2.

Figure 4 2D drawing of the model

Figure 2 Methodology used for Optimization

3. Modeling of “BEAT CHEVROLET”

The 3D model of the BEAT CHEVROLET engine mounting bracket is designed by using CATIA V5 R20. This release of CATIA, extends the Figure 5 CATIA Model of BEAT CHERVOLET power of leading edge engineering practices to include relation design, which results in Higher 3.1. Meshing quality design, the first time, More opportunities for innovation, Fewer engineering changes later in the After developing the CATIA model of the design cycle . CAITA V5 R20 portfolio brings “BEAT CHEVROLET” Engine mounting bracket it is imported into the HyperWorks to do meshing and business values in the following areas Power major analysis. In general, the tetrahedral element is used in product programs ,Process expertise, World class HyperWorks. It has quadratic displacement behavior

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Imperial Journal of Interdisciplinary Research (IJIR) Vol-3, Issue-6, 2017 ISSN: 2454-1362, http://www.onlinejournal.in and is well suited for irregular models (such as design space can be defined by using shell or solid developed from various CAD/CAM systems). The elements, or both. The classical topology tetrahedral element in HyperMesh is defined by ten optimization set up is used for solving the minimum nodes having three degrees of freedom at each node compliance problem, as well as the dual formulation and translations in the nodal x, y, and z directions. with multiple constraints. The element also consists of different mechanical properties such as plasticity, creep, swelling, stress stiffening, large deflection, and large strain capabilities. The model is meshed with tetrahedral elements and the holes are modeled with rigid elements as shown in Figure 6. It needs the checking for possibility of free edges and T edges between the nodes and elements after meshing. If the elements are free from tap collapse and free edges our meshing is fine otherwise it requires the remesh of the model to get better results. Figure 7 Optimized Model

Load location Fixed Condition Figure 6 Tetrahedral Meshed Model

3.2. Material Selection & Its Properties Figure 8 Boundary conditions for optimized mode In the present study material selection plays an 5. Analysis important role to reduce the weight of the component. In general the engine mounting brackets In this study the Static structural and modal are made up of gray cast iron due to its high analysis is carried out with the help of optimistic compressive strength and high specific heat capacity. solver for three different materials by using the hyper But due to the high density of GCI the weight of the works. component is more, so to reduce the weight of the component we have to choose high strength and low 5.1. Analysis of Existing Model density materials like AlSiC and Aluminium alloy 5052. 5.1.1. Gray Cast Iron

Table 1 Mechanical Properties of materials used In this model the load is applied at the free end and the three holes are constrained, which means that

Young s ’ Density Poisson s Material Used modulus ’ (g/mm3) ratio 4. Topology optimization (MPa) Optimization is used to reduce the weight of the Gray cast Iron 125000 7.28 0.25 existing model without changing its performance. Aluminum 115000 2.88 0.33 Based on the given loading conditions and Silicon Carbide constraints, topology optimization develops an Aluminum 70300 2.68 0.33 optimized model by removing the unwanted Alloy 5052 material. the model behaves like a cantilever beam. We know Topology optimization is used to develop an that in cantilever beam the maximum deflection optimized model for a given set of loads and occurs at free end. From the Figure 9 it is clear that constraints within a given design space without the maximum displacement of 5mm is occurred at changing the performance of the model. Here the the free end.

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Imperial Journal of Interdisciplinary Research (IJIR) Vol-3, Issue-6, 2017 ISSN: 2454-1362, http://www.onlinejournal.in

5.2. Analysis Of Optimized Model

5.2.1. Gray Cast Iron

Figure 9 Maximum Displacement of GCI As we know that for cantilever beam the max stress is developed at fixed support. From the Figure 10 it is clear that the maximum stress is developed at Figure 12 Equivalent stress of Gray cast iron fixed end and the value is 3.124MPa.In the similar Even though the removal of unwanted material, we can do the analysis for three different materials the overall strength of the component decreases, due (AlSiC and Al alloy 5052) and calculate the stresses to this effect the stress value increases at the material and displacements removal point. From the Figure 4.21, it is clear that the maximum induced stress occurs at bottom portion near the holes due to its cantilever behaviour. The stress value (5.602MPa) for optimized model is slightly greater than the existing model (3.12 MPa), due to the removal of unwanted material. The stresses for the existing model and optimized model are well below the allowable stresses of 140 MPa.

Figure 10 Equivalent stress of GCI

5.1.2. Initial weight of the component

Figure 13 Total deformation of Gray cast iron In previous case, it is already discussed that the stress value for optimized model is slightly more compared to the existing model due to the removal of unwanted material. As we know that, if stress value increases total deformation is also increases. From the Figure 4.22, it is clear that the displacement value Figure 11 Weight of the model-GCI material of optimized model of 16mm is more than the existing model of 5mm and it occurs at the free end. From the analysis the weight of GCI material is In the similar we can do the analysis for three found to be 2.44kg. In the similar way we can different materials (AlSiC and Al alloy 5052) for the calculate the weight of the component with three optimized model and calculate the stresses and different materials. displacements.

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Imperial Journal of Interdisciplinary Research (IJIR) Vol-3, Issue-6, 2017 ISSN: 2454-1362, http://www.onlinejournal.in

Variation of Deformation 0.03 Deformati 0.025 on in 0.02 0.015 mm 0.01 0.005 Base model 0

Optimized Model

Figure 14 Weight of the optimized model with Gray cast iron Materials From the analysis the weight of GCI material is 2.064e-03 tons. In the similar way we can calculate the weights of the optimized model with three Figure 16 Deformation comparison between the different models. existing model and the optimized model 6. Results and Discussion 6.2. Calculated Weights from Hyper Works In the earlier section, it is discussed that the main 6.1. Analysis Results objective of this study is to reduce the weight of the From the analysis the stress and deformation of component by using material optimization and the GCI, AlSiC and Al alloy 5052 are calculated and topology optimization. The weights of the are shown in Table 2. Based on the static structural components of different materials with different analysis, the stresses and deformations have been models is shown in Table 3. And the comparison of compared for various materials shown in Figure 15 weights are shown in Figure 17. and Figure 16. Table 3 Weight of the models with three different materials Table 2 Results obtained from the static structural analysis Existing model Optimized S.NO weight model weight (Kg) (Kg) Stress Comparision Optimi Existing 6 Existing Optimized zed model model model Stress 4 Materials model deformatio Base stress deformation 2 stress n (MPa) (MPa) (mm) 0 Model (MPa) (mm) Gray cast 3.124 5.602 0.005 0.012 optimized Iron Model Aluminu m silicon 2.937 5.391 0.006 0.017 carbide Materials Aluminu m alloy 2.937 5.391 0.010 0.027 5052

Gray cast Figure 15 Stress comparison between the existing 2.446 2.064 Iron model and the optimized model Aluminum 0.978 0.845 silicon carbide Aluminum alloy 0.910 0.786 5052

Initial Weight of the existing component = 2.446 Kg Weight of the component after material optimization = 0.910 kg Weight of the optimized model with base material = 2.064 kg

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Imperial Journal of Interdisciplinary Research (IJIR) Vol-3, Issue-6, 2017 ISSN: 2454-1362, http://www.onlinejournal.in

Weight of the optimized model after material 2015, pp. 1–6. optimization = 0.786 kg [4] S. Koushik, “Static and Vibration Analysis of InitialWeigth FinalWeight TotalWeightRe duction Engine Mounting Bracket of TMX 20-2 using InitialWeight OptiStruct,” in Altair Technology Conference, 2013, pp. 1–7. [5] S. Maski and Y. Basavaraj, “FINITE ELEMENT ANALYSIS OF ENGINE MOUNTING Total weight reduction in percentage = 67.86% BRACKET BY CONSIDERING PRETENSION EFFECT AND SERVICE LOAD,” Int. J. Res. Eng. Technol., vol. 04, no. 08, pp. 327–333, 2015. 3 2.5 2

Weight 1.5 Existing

(kgs) 1 model 0.5 Optimized 0 model gray AlSiC Al cast alloy iron 5052 Materials

Figure 17 Comparison of weight for different materials 7. Conclusion

In this study, “BEAT CHEVROLET” Engine mounting bracket is taken for the analysis. Topology optimization approach is presented to create an innovative design of an engine mount bracket. Structural and modal analyses were conducted on both the models to choose the best model. Final comparison between the existing model and optimized model in terms of stress, weight and the natural frequencies of the component. In this study, weight reduction of engine mounting bracket is taken into consideration without varying the performance of the component. Based on the results in this study, we proposed that the optimized model of Aluminium alloy 5052 is best suited for the engine mounting bracket based on the static structural analysis. 8. References

[1] Y. Basavaraj and T. H. Manjunatha, “Design Optimization of Automotive Engine Mount System,” Int. J. Eng. Sci. Invent., vol. 2, no. 3, pp. 48–53, 2013. [2] M. Deshmukh and P. K. R. Sontakke, “Analysis and Optimization of Engine Mounting Bracket,” Int. J. Sci. Eng. Res., vol. 3, no. 5, pp. 131–136, 2015. [3] V. S. K. A.S.Adkine, “DESIGN AND ANALYSIS OF ENGINE MOUNTING BRACKET USING ANSYS TOOL,” in International Journal of Innovation in Engineering, Research and Technology [IJIERT],

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