International Journal of Mechanical Engineering and Technology (IJMET) Volume 9, Issue 3, March 2018, pp. 1157 1162, Article ID: IJMET_09_03_119 Available online at http://www.iaeme.com/ijmet/issues.asp?jtype=ijmet&vtype=9&itype=3 ISSN Print: 0976-6340 and ISSN Online: 0976-6359 IAEME Publication Scopus Indexed MODAL ANALYSIS OF AN AUTOMOTIVE SUB- SYSTEM USING CAE TECHNIQUES Kiran Kumar Dama, Sai Surya, Chandu Babu, Pavan, RamKiran Department of Mechanical Engineering, Koneru Lakshmaiah Education Foundation, Vaddeswaram, Andhra Pradesh, INDIA ABSTRACT Computer Aided Engineering (CAE) plays an extreme importance in Automotive design. In new product design process, modal analysis plays a major role to find the structural modes and natural frequencies during Finite Element Analyses (FEA) simulations. This work deals with the modal analysis of automotive Cross-Car Beam (CCB) sub-system to find the structural modes and natural frequencies. In this procedure CAD modelling is generated by using Creo 2.0 and Finite Element(FE) Simulation Analysis is carried out via HyperWorks 13.0 and LS-DYNA. The main objective of this work is to optimize the Cross-Car Beam (CCB) Sub-System design before production with the maximum crashworthy concert as per the legal regulations. Key words: Computer Aided Engineering, CAE, Cross Car Beam, CCB, Finite Element Simulation Analysis, Modal Analysis Cite this Article: Kiran Kumar Dama, Sai Surya, Chandu Babu, Pavan, RamKiran, Modal Analysis of an Automotive Sub-System Using CAE Techniques, International Journal of Mechanical Engineering and Technology 9(3), 2018, pp. 1157 1162. http://www.iaeme.com/ijmet/issues.asp?jtype=ijmet&vtype=9&itype=3 1. INTRODUCTION Modal analysis is the study of the active possessions of linear structures, based on structural testing or FE (Finite Element) Analysis based simulation. These active possessions include resonance frequencies (natural frequencies or Eigen frequencies) and structural modes (Eigen modes). As the crashworthiness of an automotive is, its ability to guard its occupants and other participants, like pedestrians and other vehicles, involved in an event of impact. The Cross- Car Beam (CCB) Sub-System is one of the significant automobile Sub-Systems that helps in justifying the impact loads. Thus, proper design procedures should be engaged while designing the Cross-Car Beam structure. Figure 1 shows a typical Cross-Car Beam Sub-System. In this work, a concept design of an US based vehicle CCB was developed with reference to the packaging dimensions given by Ritza Technologies, India. Figure 2 shows the packaging dimensions of an US based vehicle Cross-Car Beam. http://www.iaeme.com/ijmet/index.asp 1157 editor@iaeme.com
Kiran Kumar Dama, Sai Surya, Chandu Babu, Pavan, RamKiran Figure 1 Concept Design of an US based vehicle CCB Figure 2 Packaging Dimensions of an US based vehicle CCB 2. DEVELOPMENT OF AUTOMOTIVE CCB SUB-SYSTEM This segment presents an impression of simplified design approaches for an automotive Cross-Car Beam (CCB) Sub-System structure. Simplified Computer Aided Modelling approaches for this work, is presented in Section 2.1. 2.1. Computer Aided Modelling As physical tests are often luxurious and tough to accomplish for multiple times CAD (Computer Aided Design) and CAE (Computer Aided Engineering) simulation tools are acknowledged as vital tools across a wide series of productions in product design and optimization. These simulation tools are vigorous to exactly forecast the safety concert of automotive parts in the incident of a crash [5]. Simulation tools of CAE are used for streamlining and margarine this compound design procedure comprises, FE (Finite Element) Modelling of the parts in a computer-generated http://www.iaeme.com/ijmet/index.asp 1158 editor@iaeme.com
Modal Analysis of an Automotive Sub-System Using CAE Techniques environment with the databases of material properties under numerous stresses and loads without the time restraints of actual calculations. Conservatively, bench mark calculations have been used to explore the structural behaviour of sample products and to progress new parts. However, such valuations are time concentrated and costly. Finite Element Analysis (FEA) cuts the sample expenditures and changes the correct design probable before the bench test [5]. 2.1.1. CAD Modeling Based on the packaging dimensions CAD model of an automotive cross-car beam sub-system was developed using CREO 2.0. This reference model would be used for the succeeding design and evaluation processes. Figure 3 shows the CAD Model of Cross-Car Beam Sub- System developed for this study. Figure 3 CAD Model of Cross-Car Beam Sub-System 2.1.2. Finite Element Modeling The Finite Element (FE) Modeling of the Cross-Car Beam Sub-System was developed by Hyper Mesh 13.0. The element size of 10mm was set as global element size to this Finite Element Mesh. In this process the mid planes of the parts were extracted and meshed with combination of Quads and Trias (i.e., mixed elements) [5]. Table 1 shows the element quality criteria of the Cross-Car Beam Sub-System Finite Element Model. Table 1 Quality Criteria of FE Modeling [5] Quality Criteria For 2D: For 3D: Warpage Jacobian Aspect Ratio Maximum Angle of Quads Minimum Angle of Quads Maximum Angle of Trias Minimum Angle of Trias % of Trias < 10 > 0.6 < 5 = 135 = 45 = 120 = 20 < 5% Warpage Jacobian Aspect Ratio Maximum Angle of Hexas Minimum Angle of Hexas Maximum Angle of Pentas Minimum Angle of Pentas % of Pentas < 30 > 0.5 < 5 = 135 = 45 = 120 = 20 < 5% http://www.iaeme.com/ijmet/index.asp 1159 editor@iaeme.com
Kiran Kumar Dama, Sai Surya, Chandu Babu, Pavan, RamKiran Figure 4 shows the Finite Element (FE) Model of Cross-Car Beam Sub-System with constraints. Figure 4 FE Model of CCB Sub-System Figure 5 shows the FE Model of CCB Sub-Assembly used for modal analysis. Figure 5 FE Model of Cross-Car Beam Sub-System for Modal Analysis 3. MODAL ANALYSIS RESULTS Two modal analyses were conducted to study dynamic frequency responses and mode shapes, includes local body stiffness and fixed boundary conditions. Figure 6 shows the obtained mode shapes of the developed model with the localized stiffness. http://www.iaeme.com/ijmet/index.asp 1160 editor@iaeme.com
Modal Analysis of an Automotive Sub-System Using CAE Techniques (i) First Mode (ii) Second Mode (iii) Third Mode (iv) Fourth Mode Figure 6 Mode Shapes with the Localized Stiffness Figure 7 shows the mode shapes for the developed model with the fixed boundary conditions. (i) First Mode (ii) Second Mode (iii) Third Mode (iv) Fourth Mode Figure 7 Mode Shapes with the Fixed Boundary Conditions 4. CONCLUSIONS This paper focuses on assessment of automotive Cross-Car Beam (CCB) Sub-System for crashworthiness. In this procedure CAD modelling is generated by using Creo 2.0 and modal http://www.iaeme.com/ijmet/index.asp 1161 editor@iaeme.com
Kiran Kumar Dama, Sai Surya, Chandu Babu, Pavan, RamKiran Analysis is carried out and found the structural modes and natural frequencies to optimize the Cross-Car Beam (CCB) Sub-System design before production with the maximum crashworthy concert as per the legal regulations using HyperWorks 13.0 and LS-DYNA. REFERENCES [1] Creo 2.0 User s Manual, PTC, Inc., 2013. [2] HyperMesh 13.0 User s Manual, Altair Computing, Inc., 2015. [3] LS-DYNA Keyword User s Manual, Livermore Software Technology Corporation (LSTC), 2015. [4] Kiran Kumar Dama, V Suresh Babu, R N Rao, and Sridhar Emmadi "Structural Performance Assessment of a Chrysler Neon Compact Passenger Vehicle by Numerical Methods", Materials Today: Proceedings, Volume 4, Issue 2, Part A, 2017, pp 1820-1828. [5] Kiran Kumar Dama, Santosh Kumar Malyala, V Suresh Babu, R N Rao and IsmailJani Shaik "Development of Automotive FlexBody Chassis Structure in Conceptual Design Phase using Additive Manufacturing", Materials Today: Proceedings, Volume 4, Issue 9, 2017, pp 9919-9923. http://www.iaeme.com/ijmet/index.asp 1162 editor@iaeme.com