PSI - Issue 14

Varatharaj Neelakandan et al. / Procedia Structural Integrity 14 (2019) 345–353 Varatharaj Neelakandan / Structural Integrity Procedia 00 (2018) 000–000

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2.4. Loads and constrains The calculated loads on the housing bearing reaction are 15022N and sun gear bearing reaction is 7108N applied as shown the Figure 5: Housing bracket FE mesh model, load and constrains. in the housing bracket using the FEA software ANSYS WB 19.0. The static safe factor 2.5 is considered for the bearing reaction load calculation as per the starter motor load test specification. The 3D model of the housing bracket is finite element meshed with solid meshing using ANSYS meshing. The quality of the meshing is controlled for the result accuracy.

Figure 5: Housing bracket FE mesh model, load and constrains

2.5. Material properties for Static and fatigue load. The housing bracket made up of the Aluminum alloy and with pressure die casting process. The housing material has the properties references by Akira Ueno (2014) to satisfy the starter motor environmental requirement as high operating temperatures, outstanding corrosive resistance, and good strength for machining feasibility, excellent thermal and electrical conductivity. The mechanical properties are given in the Table 1: Material data. This property is used for the static stress analysis calculation for analyzing the stress concentration. The calculation required S-N curve of aluminum ADC12 references by Akira Ueno (2014) housing bracket fatigue life as shown the Figure 6: Al - ADC12 S-N Curve data. The operating stress calculated based on the static stress analysis and then it has been taken for the fatigue load using Goodman diagrams method references by Varatharaj Neelakandan (2015). Table 1: Material data Housing bracket material ADC12 -Properties Values Elasticity(E) 70GPa Poisson ratio 0.30 Tensile strength 160MPa Density 7840Kg/m 3 3. Existing housing bracket stress and fatigue analysis results The housing bracket stress analysis is conducted in a static load condition for the stress prediction. The predicted stress level is 119 MPa which lower than the material stress limit of 160MPa and the static load factor of safety is 1.34 which is good level but the weight reduction of housing bracket without reduction of strength is challenge in the optimization. The fatigue analysis is conducted using the Goodman principle references by Varatharaj Neelakandan (2015) where the alternate stress is considered for the fatigue load and fatigue factor of safety included in the analysis setting. The stress life fatigue method used for the fatigue analysis reference by ANSYS conference