International Journal of Research and Innovation (IJRI)
International Journal of Research and Innovation (IJRI) 1401-1402
GEOMETRIC OPTIMIZATION AND MANUFACTURING PROCESS OF SIX CYLINDER DIESEL ENGINE CRANK SHAFT USED IN AUTOMOBILE USING FEA
Karnati Sreedhar 1,Gandhi Perumallapalli2, D.sreeramprasad
3
1 Research Scholar, Department Of Mechanical Engineering, Sri Venkateswara Engineering College, Amaravadi Nagar, Suryapet,India 2 Assistant professor , Department Of Mechanical Engineering, Sri Venkateswara Engineering College, Amaravadi Nagar, Suryapet,India 3 Associate Professor , Department Of Mechanical Engineering, Sri Venkateswara Engineering College, Amaravadi Nagar, Suryapet,India
Abstract The crankshaft is that part of an engine which translates reciprocating linear piston motion into rotation. To convert the reciprocating motion into rotation, the crankshaft has "crank" or "crankpins", additional bearing surfaces whose axis is offset from that of the crank, to which the "big ends" of the connecting rods from each cylinder attach. The aim of the project work is to optimize the geometry shape of 6-cylinder diesel engine crank shaft to reduce the failures and to reduce the weight. And also this project work will provide the brief explanation of manufacturing process. Initially literature survey and data collection will be done to understand methodology. Design calculations will be done to get parameters of object for drafting. 3D model will be prepared according to the obtained parameters. Analysis will be conducted on crank shaft to rectify failures by optimizing geometric shape. Also best material will be suggested by analyzing and comparing results with the variation of materials. Mold tool design will be done and assembly will be prepared according to that. Cnc program will be prepared for die set using cam *Corresponding Author: Karnati Sreedhar, Research Scholar, Department Of Mechanical Engineering, Sri Venkateswara Engineering College, Amaravadi Nagar, Suryapet,India Published: May 20, 2015 Review Type: peer reviewed Volume: II, Issue : II
Citation: Karnati Sreedhar, Research Scholar (2015)
GEOMETRIC OPTIMIZATION AND MANUFACTURING PROCESS OF SIX CYLINDER DIESEL ENGINE CRANK SHAFT USED IN AUTOMOBILE USING FEA
Problem Description When observing 6 cylinder automobiles like busses having frequent break downs due to engine failures. Millage is also become one of the most important thing in those days if we can reduce the mechanical efficiency. Commonly crank shafts are made with low carbon steels and casting along with milling is used to the produce object.It causes low production rate and high cost. Methodology This is an attempt to reduce weight, improve life time and to improve production rate by implementing geometric optimization we can reduce failure and by introducing new materials we can reduce weight as well as we switch manufacturing process. By implementing metal injection system we can improve production rate.
Introduction The crankshaft, sometimes casually abbreviated to crank, is the part of an engine which translates reciprocating linear piston motion into rotation. To convert the reciprocating motion into rotation, the crankshaft has "crank throws" or "crankpins", additional bearing surfaces whose axis is offset from that of the crank, to which the "big ends" of the connecting rods from each cylinder attach. It typically connects to a flywheel, to reduce the pulsation characteristic of the four-stroke cycle, and sometimes a torsional or vibrational damper at the opposite end, to reduce the torsion vibrations often caused along the length of the crankshaft by the cylinders farthest from the output end acting on the torsional elasticity of the metal. Stress on crankshafts The shaft is subjected to various forces but generally needs to be analysed in two positions. Firstly, failure may occur at the position of maximum bending; this may be at the centre of the crank or at either end. In such a condition the failure is due to bending and the pressure in the cylinder is maximal. Second, the crank may fail due to twisting, so the conrod needs to be checked for shear at the position of maximal twisting. The pressure at this position is the maximal pressure, but only a fraction of maximal pressure. A crankshaft contains two or more centrally-located coaxial cylindrical ("main") journals and one or more offset cylindrical crankpin ("rod") journals. The two108
International Journal of Research and Innovation (IJRI)
plane v8 crankshaft pictured in figure 1 has five main journals and four rod journals, each spaced 90° from its neigbors.
The crankshaft main journals rotate in a set of supporting bearings ("main bearings"), causing the offset rod journals to rotate in a circular path around the main journal centers, the diameter of which is twice the offset of the rod journals. The diameter of that path is the engine "stroke": the distance the piston moves up and down in its cylinder. The big ends of the connecting rods ("conrods") contain bearings ("rod bearings") which ride on the offset rod journals.
is becoming increasingly significant because of the feasibility and ease of adding new functions to the existing commercial products, apart form products made completely from nanomaterials through the bulk, which is relatively difficult. Nanomaterials are usually characterized by a feature size of less than 100 nm at least in one dimension. Recently in april 2010, us epa has announced a new working definition of nanomaterials as “an ingredient that contains particles that have been intentionally produced to have at least one dimension that measures between approximately 1 and 100 nanometers” in order to facilitate the implementation of regulations on use of nanomaterials in commercial products. Introduction to cad Throughout the history of our industrial society, many inventions have been patented and Whole new technologies have evolved. Perhaps the single development that has impacted Manufacturing more quickly and significantly than any previous technology is the digital computer.
Crankshaft materials The steel alloys typically used in high strength crankshafts have been selected for what each designer perceives as the most desirable combination of properties. Figure 6 shows the nominal chemistries of the crankshaft alloys discussed here. Medium-carbon steel alloys are composed of predominantly the element iron, and contain a small percentage of carbon (0.25% To 0.45%, Described as ‘25 to 45 points’ of carbon), along with combinations of several alloying elements, the mix of which has been carefully designed in order to produce specific qualities in the target alloy, including hardenability, nitridability, surface and core hardness, ultimate tensile strength, yield strength, endurance limit (fatigue strength), ductility, impact resistance, corrosion resistance, and temper-embrittlement resistance. The alloying elements typically used in these carbon steels are manganese, chromium, molybdenum, nickel, silicon, cobalt, vanadium, and sometimes aluminium and titanium. Each of those elements adds specific properties in a given material. The carbon content is the main determinant of the ultimate strength and hardness to which such an alloy can be heat treated.
Introduction to pro/engineer Pro/engineer is the industry’s standard 3d mechanical design suit. It is the world’s leading cad/cam / cae software, gives a broad range of integrated solutions to cover all aspects of product design and manufacturing. Advantages of pro/engineer 1.It is much faster and more accurate. Once a design is completed. 2D and 3d views are readily obtainable. 2.The ability to incorporate changes in the design process is possible. 3.It provides a very accurate representation of model specifying all other dimensions hidden geometry etc. 4.It provides a greater flexibility for change. For example if we like to change the dimensions of our model, all the related dimensions in design assembly, manufacturing etc. Will automatically change. 5.It provides clear 3d models, which are easy to visualize and understand. 6.Pro/e provides easy assembly of the individual parts or models created it also decreases the time required for the assembly to a large extent. Design of multi cylinder engine crank shaft (diesel engine) specifications
Nanomaterials The role of nanomaterials in modern technologies 109
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Pressure calculations Engine type: air cooled 4-stroke (Agco sisu power 66cta bus) Number of cylinders =6 Bore diameter (d) = 108 mm Stroke length (l) = 120mm Maximum combustion pressure=10.466N/mm2 Displacement =6600cc Compression ratio =23:1 Density of diesel = 874.6081Kg/m3 at 15°c T =288.855K Mass = density ×volume = 0.0000008746081×6600000 = 5.77Kg Molecular weight for diesel is 200 g/mole Pv = mrt
Assume that the length of the main bearings to be equal, i.E., C1 = c2 = c / 2. We know that due to the weight of the flywheel acting downwards, there will be two vertical reactions v2 and v3 at bearings 2 and 3 respectively, such that
Model of crank shaft
We know that force on the piston i, e: gas load
In order to find the thrust in connecting rod we should find out angle of inclination of connecting rod with line of stroke (i,e: angle ) (lies between 30° to 40°)
Assume that the distance (b) between the bearings 1 and 2 is equal to twice the piston diameter (d). B = 2d = 2 × 108 =216mm Due to this piston gas load (fp) acting horizontally, there will be two horizontal reactions h1and h2 at bearings 1 and 2 respectively, such that B1 = b2= 108mm
The above image shows total sections 2D drafting crankshaft
Powder metallurgy Powder metallurgy is a forming and fabrication technique consisting of three major processing stages. First, the primary material is physically powdered, divided into many small individual particles. Next, the powder is injected into a mold or passed through a die to produce a weakly cohesive structure (via cold welding) very near the dimensions of the object ultimately to be manufactured. Pressures of 10-50 tons per square inch are commonly used. Also, to attain the same compression ratio across more complex pieces, it is often necessary to use lower punches as well as an upper punch. Finally, the end part is formed by applying pressure, high temperature, long setting times (during which self110
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welding occurs), or any combination thereof. Cad/cam in die design In the die casting scenario the advent of digital computers has facilitated the improvement of productivity and elimination of costly rework. Here before the physical realization of the die, the design can be redefined and the parameters can be decided which would yield good results. Variety of feed systems and combination of ideas can be selected. This is an analytic approach to estimate the validity of the design. Thus it gives enormous confidence to the designer even before the tool is manufactured. Core & cavity design with pro/engineer Core cavity preparation
Create parting surface
The above image shows exploded view of complete die
Introduction to manufacturing The manufacturing of various products is done at different scales ranging from humble domestic production of say candlesticks to the manufacturing of huge machines including ships, aeroplanes and so forth. The word manufacturing technology is mainly used for the latter range of the spectrum of manufacturing, and refers to the commercial industrial production of goods for sale and consumption with the help of gadgets and advanced machine tools. Industrial production lines involve changing the shape, form and/or composition of the initial products known as raw materials into products fit for final use known as finished products. Procedure of manufacturing Cavity Roughing
Create work piece
With workpiece
The above image shows cavity 1
The above image shows total die assembly
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Cutting tool
Playpath
By the early 70's, fea was limited to expensive mainframe computers generally owned by the aeronautics, automotive, defense, and nuclear industries. Since the rapid decline in the cost of computers and the phenomenal increase in computing power, fea has been developed to an incredible precision. Present day supercomputers are now able to produce accurate results for all kinds of parameters. Fea consists of a computer model of a material or design that is stressed and analyzed for specific results. It is used in new product design, and existing product refinement. A company is able to verify a proposed design will be able to perform to the client's specifications prior to manufacturing or construction. Modifying an existing product or structure is utilized to qualify the product or structure for a new service condition.In case of structural failure, fea may be used to help determine the design modifications to meet the new condition. Introduction to ansys
Vericut
Ansys is general-purpose finite element analysis (fea) software package. Finite element analysis is a numerical method of deconstructing a complex system into very small pieces (of user-designated size) called elements. The software implements equations that govern the behaviour of these elements and solves them all; creating a comprehensive explanation of how the system acts as a whole. These results then can be presented in tabulated, or graphical forms. This type of analysis is typically used for the design and optimization of a system far too complex to analyze by hand. Systems that may fit into this category are too complex due to their geometry, scale, or governing equations. Material properties and boundary Conditions Material properties :carbon steel
Roughing program % G71 O0001 (\Roughing.Ncl.1) (04/30/15-12:13:46) N0010t1m06 S1500m03 G01g43x-377.072Y-157.018Z2.F500.H01m08 Z-2.F150. Introduction to fea Finite element analysis (fea) was first developed in 1943 by r. Courant, who utilized the ritz method of numerical analysis and minimization of variational calculus to obtain approximate solutions to vibration systems. Shortly thereafter, a paper published in 1956 by m. J. Turner, r. W. Clough, h. C. Martin, and l. J. Topp established a broader definition of numerical analysis. The paper centered on the "stiffness and deflection of complex structures". 112
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Boundary conditions Constrained at crankshaft both ends Pressure on shaft
Dynamic analysis of crankshaft Existing model
Structural analysis of crankshaft Existing model Material: carbon steel
The above image shows total deformation mode 1
The above image shows total deformation
The above image shows total deformation mode 2
Fatigue analysis of crankshaft existing model
The above image shows stress
The above image shows strain
The above image shows life
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International Journal of Research and Innovation (IJRI)
The above image shows safety factor
The above image shows biaxiality indication
Structural analysis of crankshaft Existing model Material: nano material
The above image shows total deformation
The above image shows stress
The above image shows strain
Dynamic analysis of crankshaft Existing model
The above image shows total deformation mode 1
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Modified model
2D drafting
The above image shows total deformation mode 2
Fatigue analysis of crankshaft existing model
Structural analysis of crankshaft Modified model Material: carbon steel
The above image shows life
The above image shows total deformation
The above image shows safety factor
The above image shows stress
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International Journal of Research and Innovation (IJRI)
Fatigue analysis
The above image shows safety factor
Results Table The above image shows strain
STRUCTURAL ANALYSIS Existing model
Modified model
carbon steel
Nano material
carbon steel
Nano material
Total deformation
0.00679
0.012065
0.0059
0.0104887
Stress
12.626
12.348
10.955
10.711
Strain
5.9963e-5
0.000106
5.1513e-5
9.1435e-5
Results and graphs Structural analysis
Dynamic analysis
The above image shows total deformation graph
The above image shows stress graph
Existing model
Modified model
carbon steel
Nano material
carbon steel
Nano material
Total deformation mode 1HZ
65.455
54.36
66.017
54.827
Total deformation mode 2 HZ
67.961
56.441
68.569
56.946
Total deformation mode 3 HZ
179.08
148.73
180.71
150.08
Total deformation mode 4 HZ
187.09
155.38
188.54
156.58
Total deformation mode 5 HZ
248.42
206.31
254.31
211.2
FATIGUE ANALYSIS Existing model
Modified model
carbon steel
Nano material
carbon steel
Nano material
LIFE
1e6
1e6
1e6
1e6
Damage
1000
1000
1000
1000
Safety factor
3.416
3.4903
3.9344
4.0238
Biaxiality indication
0.99856
0.99856
0.99907
0.99907
Alternating stress
25.252
24.697
21.909
21.422
The above image shows strain graph
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Conclusion This project works deals with “geometric optimization and manufacturing process of six cylinder diesel engine crank shaft used in automobile using fea� Initially literature survey and data collection was done to understand methodology. Crank shaft parameters are calculated using empirical formals for 6 cylinder engine. 3D model is prepared according to the obtained valve from calculation, Static, fatigue and dynamic analysis is done on crankshaft using low carbon steel (existing).Same as been done using steel nano material and to find out the failure locations and to evaluate results for new material. Geometric modifications are done on crank shaft model to reduce stress concentration by implementing stress reliving holes on web. As per the static, fatigue and dynamic analysis results, existing model is up to the mark only. Implementation of nano material will increase life by 2%, while appling stress reliving holes, life will be increased by 17.8% And also weight can be reduced by 22%due to low density for nano steel alloy. Also material is removed from the crank web. So better to use modified model with nano material. In the next step manufacturing is described and for the nano materials better to go with metal injection process. Mould parts are prepared and assembly, which contains ejectors, retainers, spacer housing and pins. Cnc codes are generated using cam in pro/engineer. This project concludes that modified model with nano material increases the life and also weight will be reduced up to 35% which interns increases the mechanical efficiency. Metal injection process is the most efficient way to manufacture crankshaft with nano material and also it increase the production rate References 1.Dynamic stress analysis of a multi cylinder two-stage compressor crankshaft Research journal of engineering sciences
Authour
Karnati sreedhar Research scholar, department of mechanical engineering,sri venkateswara engineering college, Amaravadi nagar, suryapet - 508213.Nalgonada (dt), india.
Gandhi perumallapalli Assistant professor in mechanical engineering Sri venkateswara engineering college, Amaravadi nagar, suryapet - 508213.Nalgonada (dt),india.
D.Sreeramprasad Associate professor in mechanical engineering Sri venkateswara engineering college, 8 Years industrial, 18 years teaching+ years
2.Design and analysis of crankshaft for single cylinder 4-stroke deisel engine Crankshaft design and optimization- a review National conference on recent trends in engineering & technology 3.Theoretical and experimental analysis of torsional and bending effect on four cylinders engine crankshafts by using finite element approach International journal of engineering research 4.Fatigue strength and residual stress analysis of deep rolled crankshafts International journal of engineering and technology (ijet) 5.Finite element analysis of 4-cylinder diesel crankshaft 6.Crankshaft strength analysis using finite element method International journal of engineering research 7.Concept and manufacture of a crankshaft production tool 8.Elastic multi body simulation of a multi-cylinder engine The open mechanical engineering journal,
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