DESIGN AND ANALYSIS OF CONNECTING ROD

Transcription

1 DESIGN AND ANALYSIS OF CONNECTING ROD 1 GANTA.KRISHNARJUNA REDDY, 2 BADDE NAIK VADITHE 1 pg Scholar, Department of Mechanical Engineering, Nalanda institute of engineering and technology, Sattenapalli, Guntur, Andhra Pradesh Associate Professor of Mechanical Engineering, Nalanda institute of engineering and technology, Sattenapalli, Guntur, Andhra Pradesh ABSTRACT Connecting rod is one of the most important parts in automotive engine. Connecting rod is the link between piston and crank shaft. Which it converts reciprocating motion of piston into rotary motion of crank shaft.in internal engines connecting rod is mainly made of steel and aluminum alloys (for light In a weight and absorb high impact loads) or titanium (for higher performance engines and for higher cost).as a connecting rod is rigid, it may transmit either a push or a pull and so the rod may rotate the crank through both halves of a revolution, i.e. Piston pushing and piston pulling. Earlier mechanisms, such as chains, could only pull. In a few two-stroke engines, the connecting rod is only required topush. In which it undergoes structural deformations. Thus in this project we are modeling a connecting rod in solid works 2016 design software and doing static structural analysis in ansyswork bench 14.5 software. Thus the part which is modeled is converted into igs file to import in ansys work bench and static structural analysis is carried out at 1 MPAof pressure load by applying various materials including composite materials, materials used in this project are such as aluminum alloy (which is already existing), 42CrMo4 (Special alloy steel), H.S.C.F (high strength carbon fiber) By applying these boundary conditions on connecting rod the unknown variables such as stress, deformation, strain, and imum shear stress are found using the FEA based software(ansys). 1. INTRODUCTION Reciprocating position engine to the connecting rod or con-rod connects the piston to the crank or crankshaft, alongside the crank they form a simple mechanism converts reciprocating motion into rotating motion. Connecting rod might also converts rotating motion into reciprocatory motion. Traditionally to development of engines they were first using this manner. As a connecting rod is rigid, might transmit either push or pull and then the rod might rotate each halves of a revolution i.e. Piston pushing and piston pulling. Earlier mechanisms used like chains, may solely pull in a very few two-stroke engines, the connecting rod is barely needed to push. Now days, connecting rods are best well-known through their use in a internal combustion piston engines like automotive engines. These are clearly different forms earlier types of the connecting rods utilized in stream engines and steam locomotives.

2 of a connection rod is to provide fluid movement between pistons and a crankshaft and therefore the connecting rod is beneath tremendous stress from the load represented by the piston. When building a high performance engine, great attention is paid to the connecting rods. The most effective feature of a connecting rod ought to be the uniform shape. Figure1.1connecting rod with piston 1.1 Importance of Con Rod InEngine The connecting rod is that the main a part of the engine, additionally backbone of the engine. There is most significant of the connecting rod in an engine. Figure1.2connecting rod in engine Connecting rod rotates the crank shaft that helps the engine to maneuver on or any of the vehicles to rotate its wheels. It is designed to resist stresses from combustion and piston movement. Connecting rods is toward lighter weight components. It should withstand with greater power loads though it is lower in weight. The main purpose The cross section of rod beam design ought to be spread and minimize stress load over massive uniformly shaped areas. In operation stress are generated and radiate from one or more source on a component because the rod functions. Top dead center (TDC) is the point at which the piston is closest to the cylinder head. Bottom dead center (BDC) is the point at which the piston is farthest from the cylinder head. Displacement is the volume that a piston displaces in an engine when it travels from TDC to BDCduring the same piston stroke. Literaturesurvey Hippoliti (1993) reported design methodology in use at piaggio for connecting rod design, which incorporates an optimization session moreover neither the details of optimization nor the load under which optimization was performed were discussed. Two parametric fe using 2d plane stress and 3d approach developed by the author were compared with experimental results and have good agreements and optimization procedure they developed was based on the 2d approach. Pai (1996) explains an approach to optimize shape of connecting rod subjected to a load cycle and consisting of the inertia load deducted from gas load as one extreme and peak inertia load exerted by the piston assembly mass as the other extreme, with

3 fatigue life constraint. Fatigue life defined as the sum of the crack initiation and crack growth lives, was obtained using fracture mechanics principles. The approach used finite element routine to first calculate the displacements and stresses in the rod; these were then used in a separate routine to calculate the total life. The stresses and the life were used in an tensile stress over the same cycle. While investigating a connecting rod failure that led to a disastrous failure of an engine, rabb (1996) performed a detailed feaof the connecting rod. He explains as well as modeled the threads of the connecting rod, the threads of connecting rod screws, the pre-stress in the screws, the diametric interference optimization routine to evaluate the objective between the bearing sleeve and the crank end of the function and constraints. The new search direction was determined using finite difference approximation with design sensitivity analysis. The author was able to reduce the weight by 28%, when compared with the originalcomponent. Sonsino and esper (1994) his discussed the fatigue based on sintered connecting rods design and it s not performing optimization of the connecting rod. They also designed a connecting rod with a load amplitude connecting rod, the diametric clearance between the crank and the crank bearing, the inertia load acting on the connecting rod, and the combustion pressure. The analysis clearly indicated the failure location at the thread root of the connecting rod, caused by improper screw thread profile. The connecting rod failed at the location indicated by the fea. An axi-symmetric model was initially used to obtain the stress concentration factors 9 at the thread root. These were fa = 19.2 knand with different regions being used to obtain nominal mean and alternating stresses designed for different load ratios (r), such as, in the stem fm= -2.2 knand r = -1.26, at the piston pin end fm= -5.5 knand r = -1.82, at the crank end fm= 7.8 kn and r = Based on this measurements performed preliminary fea followed by production of aprototype. in the screw. A detailed feaincluding all the factors mentioned above was performed by also including a plasticity model and strain hardening. Based on the comparison of the mean stress and stress amplitude at the threads obtained from this analysis with the endurance limits obtained from specimen fatigue Ishida et al. (1995) measured the stress variation at the column center and column bottom of the connecting rod, as well as the bending stress at the tests, the adequacy of a new design was checked. Load cycling was also used in inelastic feato obtain steady statesituation. column center. The plots, shown in figures 1.5 and 1.6 indicate that at the higher engine speeds, the peak tensile stress does not occur at 360o crank angle or top dead center. It was also observed 8 that the r ratio varies with location, and at a given location it also varies with the engine speed. The imum bending stress magnitude over the entire cycle (0o to 720o crank angle) at rev/min, at the column In a published sae case study (1997), a replacement connecting rod with 14% weight savings was designed by removing material from areas thatshowed high factor of safety. Factor of safety with respect to fatigue strength was obtained by performing feawith applied loads including bolt tightening load, piston pin interference load, compressive gas load and tensile inertia load. Centerwas found to be about 25% of the peak

4 The study lays down certain guidelines regarding the Structural factors considered for weight reduction use of the fatigue limit of the material and its during the optimization include the buckling load reduction by a certain factor to account for the asforged surface. They also indicate that buckling and bending stiffness are important design factors that must be taken into account during the design process. On the basis of the stress and strain measurements performed on the connecting rod, close agreement was found with loads predicted by inertia theory. The study also concludes that stresses due to bending loads are factor, stresses under the loads, bending stiffness, and axial stiffness. Thus, the component can give the higher strength, efficient design and lighter that would create a major success in the automotive and manufacturing industry. Among the main objectives are to improves the engine performance and also to strengthen the product that is ensure the safety of human being. substantial and should always be taken into account during any designexercise. Connecting rod failed due to insufficient strength to hold the load. Increasing the strength, automatically it 2. Problemstatement 3.0 problemstatement: Connecting rod is one of the most critical components internal combustion. Connecting rod is connected in will longer the life cycles of the connecting rod. In this study, the design of the connecting rod will be modeled and at the same time increase the strength. And different materials are applied for gaining more between the piston and crank shaft. While the crank stability. The study will be focus on the finite shaft rotates piston moves from bottom dead centre to top dead centre vice versa. In this process connecting rod undergoes stress and deformation. Hence for the connecting rod when the load is applied, how the stresses and strain are induced in the component and deformation value, due to applied load areanalysed. Decreasing these stresses and increasing stability depends upon the materials applied. Thus in industrial purpose optimization of connecting rod had already started. Optimization is really important for automotive industry especially. Optimization of the component is to make the less time to produce the product that is stronger, lighter and less total cost productions. The design and weight of the connecting rod influence on car performance. Hence, it effectson element modeling and analysis. From the analysis results, the decision whether connecting rod needs to change in material, load, design etc factors which induces stress in thecomponent. 3.1 Objectives of project The objectives of the project are as follows (i) To develop structural modeling of connectingrod (ii) To perform finite element analysis of connecting rod (iii) Suitable materialstudy (iv) Study of loadfactors (v) Study of stress, strain deformation induced in the connectingrod (vi) To develop structural optimization model of connectingrod the car manufacture credibility. Change in the design and material results a significant increment in weight and also performance of the engine. The

5 4.Introduction to solidworks Solidworks mechanical design automation software is a feature-based, parametric solid modeling design toolwhich advantage of the easy to learn windows TM graphical user interface. We can create fully associate 3-D solid models with or without while utilizing automatic or user defined relations to capture design intent. 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 relations, which allow them to capture design intent A Solid Works model consists of parts, assemblies, and drawings. Typically, we begin with a sketch, create a base feature, and then add more features to the model. (One can also begin with an imported surface or solidgeometry). We are free to refine our design by adding, changing, or reorderingfeatures.. 5.Design procedure of ConnectingRod For designing the Connecting Rod the following procedure has to be follow Sketch & extrude Extrude cut it to 2mm Make Holes 2d sketch of a connecting rod draw a sketch on front plane for bolting holes

6 mirror is used for making for symmetry on both sides fillet the edges for smooth surfacing material property, force value, or any other input. Define materialproperties. Specify restraints andloads. The program automatically creates a mixed mesh when different geometries (solid, shell, structural members etc.) exist in the model. Define component contact and contactsets. Mesh the model to divide the model into many small pieces called elements. Fatigue and optimization studies use the meshes in referencedstudies. Run thestudy. Viewresults. 6.1Analysis on connecting rod by using ansys 14.5 work benchsoftware The analysis of connecting rod models are carried out using ANSYS software using Finite Element Method. Firstly the model files prepare in thesolidworkssoftware. Then are exported to ANSYS software as an IGES files as shown in figure Different Views of Connecting Rods 6.ANALYSIS DEFINATION &STEPS: The steps needed to perform an analysis depend on the study type. You complete a study by performing the following steps: Create a study defining its analysis type and options. If needed, define parameters of your study. A parameter can be a model dimension, Figure5.1 structural analysis

7 Materials and theirproperties Materi al Alumi nim alloy Density( kg/m 3 ) Youngs modulus (mpa) Poisons ratio E Shear modul us(mp a) E+10 Bulk modulus(mp a) E Material: AluminiumAlloy Maximum Stress 42Cr Mo E H.s.c.f E E E E E+10 Meshing Meshing is probably the most important part in any of the computer simulations, because it can show drastic changes in results you get. Meshing means you create a mesh of some grid-points called 'nodes. It's done with a variety of tools & options available in the software. The results are calculated by solvingtherelevant governing equations numerically at each of the nodes of the mesh. The governing equations are almost always partial differentia equations, and Finite element method is used to find solutions to such equations. The pattern and relative positioning of the nodes also affect the solution, the computational efficiency &time. Total Deformation Maximum Strain Mesh Type: Tetrahedral No. of nodes: No. of elements:62544

8 6.2Material: 42CrMo4 Maximum Stress 6.2Material: High Strength Carbon Fiber Maximum stress Total Deformation Total Deformation Maximum Strain Maximum Strain

9 Load 1.5Mpa Material:aluminium alloy Maximum stress Material:42Crmo 4 Maximum stress Maximum deformation Maximum deformation Maximum strain Maximum strain

10 Material: high strength carbon fiber Maximum stress 7. RESULT AND DISCUSSION Load 1mpa materials Stressn /mm 2 Deformation mm Strain AL-alloy CrMo H.s.c.f Load 1.5 mpa Maximum deformation materials Stress n/mm 2 Deformatio n strain AL-alloy Max CrMo Max H.s.c.f Max Maximum strain For comparisons of the results obtained From the static analysis result tables it is concluded that 42CrMo4 show least stress and least deformation & strain value on same static load condition. From the above results, we are able to conclude that 42CrMo4 is the best appropriate material for the fabrication of connecting rod when compared with the applied materials followed by aluminum alloy and high strength carbon fiber

11 8. CONCLUSION Brief study about connecting rod & it s working isdone in thisproject Modeling and analysis of connecting rod is done. Modeling of connecting rod is done in solid works 2016 designsoftware The file is saved as igs to import in ansysworkbench The analysis in ansysis extremely important prior to the fabrication of connectingrod. The static structural analysis has carried out in the ansys14.5 software package for connecting rod by different materials like aluminum alloy, 42crmo4 (special steel alloy) and High strength carbon fiber. The material properties and brief explanation about composites hasgiven. The utmost stress, strain and deformation values of static analysis are tabulated on load condition of 1Mpa and 1.5 Mpa. From result we conclude that on given load condition of 1Mpa&1.5Mpa special alloy steel 42CrMo4 showing less deformationvalue. Hence the materials with low stress values are also preferable for the fabrication of connectingrod. As titanium is very costly material its application is limited can only use for aero spaceindustries. High strength carbon fiber which is less costly and less weight ratio showing nearly same stress value of AL alloy and less deformation value after 42CrMo4 can consider best material for automobile other than general material. 9.REFERENCES [1] Abhinavgutam et al. static stress analysis of connecting rod using finite element approach. Isor journal of mechanical and civil engineering, volume 10, issue 1(nov dec. 2013), pp [2] Ram bansal et al. Dynamic simulation of a connecting rod made of aluminium alloy using finite element analysis approach. Isor journal of mechanical and civil engineering, volume 5, issue 2 (jan feb.2013), pp [3] Kuldeep b et al. analysis and optimization ofconnecting rod using alfasic composites. Journal of ijirset, vol. 2, issue 6, june2013. [4] Pravardhan s. Shenoy et al. dynamic load analysis and optimization of connecting rod. In histhesis. [5] Gvsssharma andp.srinivasraoprocess capability improvement of an engine connecting rod machiningprocess. [6] K. Sudershnkumar, dr. K. Tirupathireddy, syedaltafhussain, modeling and analysis of two wheeler connecting rod international journal of modern engineering research vol-2, issue-5, pp ,sep-oct 2012 [7] Suraj pal, sunilkumar, design evaluation and optimization of connecting rod paramaters using fem international journal of engineering and management research vol-2,issue-6,dec [8] Vivek c.thade,bhumeshwarpatl eajayn.ingale stress analysis of ic engines connecting rod by fem international journal of engineering and innovative technology, vol-1,issue-3,march2012 [9] Priyankd. Toliya, ravi c. Trivedi, prof. Nikhil j. Chotai, design and finate element analysis of aluminium-6351 connecting rod international journal

12 of engineering and management research and technology vol- 2,issue 5 may 2013 [10] S.shaari, m.m.rahman, m.m.noor, k. Kadirgama and a.k. amirruddin design of connecting rod of internal combustion engine: a topology optimization approachm. National conference in mechanical engineering research and post graduate studies( 2 nd ncmer 2010) 3-4 dec 2010, pp [11] Bhuptanik.m structural analysis of bush bearing for small end connecting rod using pro mechanica issn x nov 12 to oct13, vol- 02, AUTHORS 1. Ganta.KrishnarjunaReddy Department of Mechanical Engineering, College name:nalanda institute of engineeringand technology, Village: kantepudi Mandal: sattenpalli, Dist: guntur A.P, India, Pin: id: gkrishnarjunareddy@gmail.com 2. Baddenaik.vadithe Associate Professor of Mechanical Engineering, College name:nalanda institute of engineeringand technology,village: kantepudi Mandal: sattenpalli, Dist: guntur A.P, India, Pin: id: bharathnaik117@gmail.com