Non-Linear Simulation of Front Mudguard Assembly

Transcription

1 Non-Linear Simulation of Front Mudguard Assembly Jasdeep Singh Sr. Engineer - R&D, CAE International Tractor Limited (Vill. Chak Gujran) Jalandhar Road Hoshiarpur, Punjab jasdeep.s@sonalika.com Vibhay Kumar Sr. Manager - R&D, CAE International Tractor Limited (Vill. Chak Gujran) Jalandhar Road Hoshiarpur, Punjab vibhay.kumar@sonalika.com Satpal Singh Saini Head - R&D, CAE International Tractor Limited (Vill. Chak Gujran) Jalandhar Road Hoshiarpur, Punjab satpal@sonalika.com Abbreviations: FEA - Finite Element Analysis Keywords: Plastic Mudguard, Geometric non-linearity, Material non-linearity, Contacts Abstract Tractor mudguard exhibits the susceptibility to failure under varied dynamic loads in operations like plouging, puddling, impacts from soil thrown in by tyres, etc. Large tyres of high HP series tractor presents a different challenge in mudguard design, as its soiling range is also considerably extensive. An intelligent front mudguard assembly design in this case is necessary, that can swivel about kingpin axis to facilitate adequate coverage of outer front tyre during cornering of tractor. This paper describes modeling of plastic front mudguard and simulating its behavior by using Hyperwork non-linear geometric, material and contact capabilities. Hyperwork helped in simulating realistic simulation of front mudguard assembly under different loading conditions. Vibration data taken from testing is used to determine the g levels for FEA simulation in longitudinal, transverse and vertical direction. Introduction Mudguard is an essential component of tractor to keep off operator and tractor from road sprays, mud, water and other debries thrown in by tyres during various field applications. Design of front mudguard assembly for 110HP series tractor comprises of plastic mudguard attached to mudguard resting frame, which can swivel about kingpin axis because of its mounting on horizontally aligned base casting and frames as shown in Figure 1. This single arm arrangement turns with outer front tyre during cornering of tractor and significantly reduces the soiling range without mudguard interfering with tractor s structure. Vibrations characteristics exhibited by this single arm arrangement are quite high due to overhung conditions of mudguard assembly. Therefore, FEA simulation is required for the maximum g level accelerations of mudguard assembly to know structure s integrity and failure conditions. Measurement tests for maximum g accelerations emanating at front mudguard s base plate is conducted by testing department at R&D, ITL Hoshiarpur. To verify structural strength of front mudguard assembly non-linear geometric analysis was carried out considering geometric, material and contact non-linearity. 1

2 FE Modeling: Mudguard, slotted plate, hollow section of supporting frame, support plate, base frame assembly were modeled using shell elements. Base casting, side frame, base plate assembly, stopper plate and a part of mudguard resting frame were modeled using solid elements. Rigid and beam elements were used to represent bolts. Three different load cases were simulated to analyse stresses in front mudguard assembly for acceleration in longitudinal, lateral and vertical direction. Mudguard Mudguard resting frame Base Frame Vertical & Horizontal Pin of Base Plate Base Casting Slotted plate, Side bar, Support plate Figure 1: Front Mudguard Assembly 2

3 Contact Elements were defined at the interface of following components: i. Mudguard and mudguard resting frame ii. Mudguard and side frame iii. Side frame and base frame vertical iv. Base frame horizontal and Base Casting v. Base casting and pin of base plate assembly vi. Pin and base plate Material: For Mudguard non-linear material properties of ABS plastic were defined to capture its plastic behaviour more accurately in geometric non-linear (implicit static) analysis. Linear material properties were assumed for remaining metallic components of front mudguard assembly. Loads and Boundary Conditions: Figure 2: Loads and Boundary Conditions Boundary Condition: Fully constrained at Base Plate holes. Load: Measured maximum acceleration in Longitudinal, Transverse & Vertical direction is applied as gravity load. 3

4 Results & Discussions Geometric non-linear (implicit) analysis results were post processed in hyperview. von-mises stress results were observed are shown in figure 3, figure 4 and figure 5 for longitudinal, transverse and vertical axis respectively. Animation of displacement results simulated a realistic behaviour of mudguard assembly. Location of maximum stress generated in FE analysis of front mudguard assembly were correlated with practical testing. Stresses outcome in analysis were closely matched with testing results. Figure 3: Displacement and von-mises stress results for acceleration in longitudinal (X) direction. Figure 4: Displacement and von-mises stress results for acceleration in transverse (Y) direction 4

5 . Figure 5: Displacement and von-mises stress results for acceleration in vertical (Z) direction. Benefits Summary An accurate simulation of front mudguard assembly is achieved by use of contacts at interface and non- linear material properties of plastic component in Geometric Non-linear (implicit static) analysis. Challenges Finding appropriate contact types and properties at the interface components. Convergence and solving of geometric non-linear analysis. Conclusions A linear static analysis for above case would put lot of things on assumptions and exhibited incorrect behaviour of assembly and stresses outcome. Therefore geometric non-linear analysis is always preferred to simulated an accurate behaviour. Maximum stress location generated in FE analysis were correlated with practical testing of front mudguard assembly. Contact Convergence and solving capabilities of geometric non-linear analysis is better in HM13.0 as compared to HM12.0. ACKNOWLEDGEMENTS The authors would like to International Tractors Limited - R&D and Altair India for their technical support in publishing this work. REFERENCES [1] Altair Hyperworks help manual and tutorials. 5

6 6