DESIGN AND DYNAMIC ANALYSIS OF CRANKSHAFT IN LIGHT WEIGHT

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1 DESIGN AND DYNAMIC ANALYSIS OF CRANKSHAFT IN LIGHT WEIGHT S.Joseph Irudaya Raja 1, Sathishkumar G 2, S.Sivaganesan 3, R.Sridhar 4, 1,2,3,4 Department of Mechanical Engineering, Vels Institute of Science Technology & Advanced Studies-Chennai Abstract - The main objective of this study to analyze the average von-misses stress and principle shear stress over the crankshaft using FEA software, the model creation can be created by well-known 3D modeling software. Ansys will be used as a tool for analysis and optimization of crankshaft. The crankshaft conducting static analysis and dynamic analysis using modal analysis to find total deformation and frequency of the crankshaft. While the converting the reciprocating motion into rotary motion by the crankshaft, it is subjected to vertical load and the vibrations. The study to be carried out to check the load carrying capacity of the crank shaft subjected to both vibration and rotation. Static and dynamic simulation is conducted on the forged steel crankshaft, single cylinder four stroke engines. Keywords: Crankshaft, Modeling, Finite Element Analysis, Optimization I. INTRODUCTION The crankshaft plays a vital role in all Internal Combustion Engine. It is a large component, which is converts the reciprocating displacement of the piston to a rotary motion with a four link mechanism. It has complex shape of geometry. The crankshaft experiences a cyclic load, due to the cyclic load fatigue failure occur over a period [3, 4 and 5]. The fatigue analysis has to be considered in the design stage itself. The design and development of crankshaft is always been an important task for the production industry, in order to reduce the manufacturing cost of the product minimum weight possible and proper fatigue strength and other functional requirements [8,9]. These improvements result in lighter and smaller engines with better fuel efficiency and higher power output. This study was conducted on a single cylinder four stroke cycle engine [13, 14]. Two different crankshafts from similar engines were studied in this research. The finite element analysis was performed in four static steps for each crankshaft [20, 21and 22]. Stresses from these analyses were used for superposition with regards to dynamic load applied to the crankshaft. Further analysis was performed on the forged steel crankshaft in order to optimize the weight and manufacturing cost. DOI: /IJRTER JCTZR 622

2 Figure 1. Crankshaft nomenclature II. MODELING AND METHODS 2.1 Pro E /Engineer Pro/Engineer is a 3-D modeling tool. Unlike other 3-D modeling tools, Pro/Engineer is not fully three dimensional. Other programs allow the user to easily draw in three dimensional space. In Pro/Engineer, one draws in a plane and then extrudes solids from the plane. Planes are used to obtain position in three dimensional space. It is possible to draw in three dimensional space using Pro/Engineer, but is very difficult. Therefore the best method of creating three dimensional objects is using planes. The process methodology for Robotic arm is start form geometric modeling, which has been done using solid modeling software called Pro/Engineer. Pro/Engineer is a paranoid-based solid modeler, and utilizes a parametric feature-based approach to create models and assemblies. Parameters refer to constraints whose values determine the shape or geometry of the model or assembly. Parameters can be either numeric parameters, such as line lengths or circle diameters, or geometric parameters, such as tangent, parallel, concentric, horizontal or vertical, etc. Numeric parameters can be associated with each other through the use of a relation, which allows them to capture design intent. Design intent is how the creator of the part wants it to respond to changes and updates. Pro/Engineer allows you to specify that the hole is a feature on the top surface, and will then honor your design intent no matter what the height you later gave to the can. Features refer to the building blocks of the part. They are the shapes and operations that construct the part. Shape-based features typically begin with a 2D or 3D sketch of shapes such as bosses, holes, slots, etc. This shape is then extruded or cut to add or remove material from the part. 2.2 Finite Element Analysis and Modeling The finite element method is numerical analysis technique for obtaining approximate solutions to a wide variety of engineering problems. Because of its range and flexibility as an analysis tool, it is receiving much attention in almost every industry. In more and more engineering situations today, we find that it is necessary to obtain approximate solutions to problem rather than exact closed All Rights Reserved 623

3 solution. It is not possible to obtain analytical mathematical solutions for many engineering problems. An analytical solutions is a mathematical expression that gives the values of the desired unknown quantity at any location in the body, as consequence it is valid for infinite number of location in the body. Finite element method is used to solve physical problems involving complicated geometries, loading and material properties which cannot be solved by analytical method. This method is extensively used in the field of structural mechanics, fluid mechanics, heat transfer, mass transfer, electric and magnetic field problems. For problems involving complex material properties and boundary conditions, the engineer resorts to numerical methods that provide approximate, but acceptable solutions. The finite element method has become a powerful tool for the numerical solutions of a wide range of engineering problems. It has been developed simultaneously with the increasing use of the high-speed electronic digital computers and with the growing emphasis on numerical methods for engineering analysis. This method started as a generalization of the structural idea to some problems of elastic continuum problem, started in terms of different equations. The present investigation is aimed to study the given disk brake rotor of its stability and rigidity (for this Thermo coupled Structural analysis is carried out on a given disk brake rotor) and best combination of parameters of disk brake rotor like Flange Wall thickness and material there by a best combination is suggested. Figure 2. Pro-E Models of crankshaft III. RESULTS AND DISCUSSION After completion of the finite element model it has to constrain and load has to be applied to the model as shown in figure 3. User can define constraints and loads in various ways. All constraints and loads are assigned set ID. This helps the user to keep track of load All Rights Reserved 624

4 Figure 3. Boundary conditions of crank shaft Figure 4. Displacement of crankshaft Figure 5. Maximum stress value of crank shaft Figure 6. Equivalent stress & Yield strength of crank shaft Figure 7. Displacement of crank All Rights Reserved 625

5 Stress analysis of crankshaft is maximum stress is ananlysised using ansys software as shown in figure. the maximum stress value is 28.6MPa. The maximum value of equivalent stress, yield strength, factor of safety and displacement of the crank shaft values are 84.9MPa, 800MPa, 9 and 0.55E-4 m as shown in figure 4, 5, 6 and 7. IV. CONCLUSION In this project, automobile crankshaft has been taken for the finite element analysis. Initially existing crankshaft has been done analysis with different loading condition as per the table discussed in the previous chapter ( i,e) compressive and tension load on the both crank end and connecting end and results discussed in the table itself. From the above contours the maximum displacement is almost negligible.the maximum stress induced in the crankshaft due to maximum bending and torsion is 84.9 Mpa. This value well below the permissible one. Therefore it is proved that the above design is safe.above results of modified connecting rod is done for case 1, the comparative results are higher than the existing crankshaft, but the values are safe i,e below the yield stress of 800 MPa. So that our modified connecting rod is safe and we optimized nearly 20% of the weight of the existing crankshaft. If we save 20% of material in each crankshaft, it will be economically better solution for the manufacturer. REFERENCES I. Thin-Lin Horng, Analytical Solution of Vibration Analysis on Fixed-Free Single-Walled Carbon Nanotube-Based Mass Sensor, Journal of Surface Engineered Materials and Advanced Technology, 2012; 2(1): PP II. J S Wu And H-M Chou, Free Vibration Analysis Of A Cantilever Beam Carrying Any Number Of Elastically Mounted Point Masses With The Analytical-And-Numerical-Combined Method, Journal of Sound and Vibration, 1998, 213(2): PP III. Tarsicio Beleandez, Cristian Neipp, Numerical and Experimental Analysis of a Cantilever Beam: a Laboratory Project to Introduce Geometric Nonlinearity in Mechanics of Materials, Int. J. Engng Ed., 2003;19(6): PP IV. J. J. Wu and A. R. Whittaker, The Natural Frequencies and Mode Shapes Of A Uniform Cantilever Beam With Multiple Two-DOF Spring Mass Systems, Journal of Sound and Vibration, 1999; 227 (2): PP V. S.S Queini, A.H Nayfeh, single mode control of a cantilever beam under principal parametric excitation, journal of sound and vibration 224 (1999) VI. M.MKannel, Y.A.Amer, response of parametrically excited one degree of freedom system with nonlinear damping and stiffness, Physica Scripta 66 (2002) VII. C.Chin, A.H.Nayfeh, W. Lacarbonara, two-to-one internal resonance in parametrically excited buckled beam, AIAA, 1997; 97 : VIII. Haxton RS, Barr ADS. The auto parametric vibration absorber, ASME J.Eng Industry 1972; 94: IX. Brian J. Schwarz & Mark H. Richardson," EXPERIMENTAL MODAL ANALYSIS", CSI Reliability Week, Orlando, FL, Oct X. D. Ravi Prasad and D.R. Seshu ''A STUDY OF DYNAMIC CHAARECTERISTIC OF STRUCTURAL MATERIALS USING MODAL ANALYSIS'' Asian journal of civil engineering. XI. D.Y. Zheng. Free Vibration Analysis of a Cracked Beam By finite Element Method. Journal of Sound and Vibration, 2004: XII. Huszar, Zsolt. Vibration of cracked reinforced and prestressed concrete beams Architecture and Civil Engineering, Vol. 6, 2008: XIII. G.M.Owolabi, S23wamidas, SeshadrI Crack detection in beams using changes in frequencies and amplitudes of frequency response functions. Journal of Sound and Vibration, 265(2004) 1-22 XIV. M.Behzad, Ebrahimi, A.Meghdari. A continuous vibration theory for beams with a vertical edge crack. Mechanical Engineering, Vol. 17, 2010: XV. E. I. Shifrin. Natural Frequencies of a Beam with an Arbitrary Number of Cracks. Journal of Sound and Vibration, 222(3), 1999: XVI. Duryodhan, N. S. et al,life Determination by Fatigue Analysis and Modal of Intermediate Steering Shaft and Its Optimization, International Journal of Science Technology & Engineering (IJSTE), Volume 2, Issue 1, July All Rights Reserved 626

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