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http://doi.org/10.22214/ijraset.2020.5175
May 2020
International Journal for Research in Applied Science & Engineering Technology (IJRASET) ISSN: 2321-9653; IC Value: 45.98; SJ Impact Factor: 7.429 Volume 8 Issue V May 2020- Available at www.ijraset.com
Design & Analysis of Crankshaft by ForgedSteel & Composite Material Aatish Chaudhary1, Abhishek Mishra2, Devendra Raj Pandey3, Jiyaul Mustafa4 1, 2, 3
B.tech students, Assistant Professor, School of Mechanical Engineering, Galgotias University, India
Abstract: Crankshaft is one of the critical components for the effective and precise working of the internal combustion engine. In this paper a dynamic simulation is conducted on a crankshaft from a single cylinder 4- stroke petrol engine. A threedimension model of petrol engine crankshaft is created using SOLID WORKS software. Finite element analysis is performed to obtain the variation of stress magnitude at critical locations of crankshaft. The dynamic analysis is done using FEA Software called ANSYS. This load is applied to the FE model in ANSYS, and boundary conditions are applied according to the engine mounting conditions. The overall objective of this paper is to evaluate and compare the stress analysis and deformation in different loads of two competing manufacturing technologies for automotive crankshafts, namely forged steel and composite material. I. INTRODUCTION Crankshaft is an extensive segment with a perplexing geometry in the engine, which changes over the reciprocating displacement of the piston into a rotating movement with a four link mechanism. Since the crankshaft encounters countless cycles amid its service life, fatigue performance and toughness of this part must be considered in the design procedure. Design improvements have dependably been an imperative issue in the crankshaft creation industry, so as to fabricate a more affordable component with the base weight conceivable and appropriate fatigue strength and other useful prerequisites. These enhancements result in lighter and smaller engine with better fuel efficiency and higher power output. II. PROBLEM SPECIFICATION In the present automotive market, the industries which manufacture automotive components always aim at manufacturing the components with the highest quality, excellent reliability and minimum possible cost. It is highlighted in many studies that engine related components are maximum prone to failure, followed by the drive train components. Owing to the intricate geometry and sudden changes in area in a crankshaft, it has high chances of accumulation of stresses, leading to failure. In addition, it is acted upon by bending and torsion loads since it is a rotating element. Similar is the case with a camshaft. Due to this, it is very complicated to determine the exact values of loads acting on the crankshaft and camshaft. The life of any component is mainly dependent on its design, material and manufacturing method. III.
THEORETICAL ANALYSIS
A. 1) a) b) c) d) e) f) g)
Geometric Details Of Forged Steel Material Type: Forged Steel Designation:-42Cr Mo4 Yield strength (MPa):- 680 Ultimate Tensile Strength(MPA):-850 Elongation (%):-13 Poisson ratio:-0.3 Young’s Modulus:-210E3 MPA Density:-7.9 g/cm3
2) a) b) c) d) e) f) g)
Material Type: Composite Material Designation:- Epoxy Poisson ratio:- 0.3 Young’s Modulus:-140 Density:-1.6 Yield strength (MPa):-1900 Applied Pressure = 100 Bar Avg. Speed (N) = 1800 rpm, so angular velocity = ω= 2πN/60 = 188 rad/s
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International Journal for Research in Applied Science & Engineering Technology (IJRASET) ISSN: 2321-9653; IC Value: 45.98; SJ Impact Factor: 7.429 Volume 8 Issue V May 2020- Available at www.ijraset.com IV. SPECIFICATION OF CRANKSHAFT Table 1 Physical parameters Crankpin diameter (mm) Crankpin axial length (mm) Diameter of shaft (mm) Web thickness (mm Web width (mm)
Values 50 24 32 23 125
V. ANSYS ANSYS is the standard FEA teaching tool within the Mechanical Engineering Department at many universities and colleges. ANSYS is also used in Civil and Electrical Engineering VI. STATIC ANALYSIS The design of crankshaft has been done in CATIA and is save the part in ICGS file format. The file has been ex- ported in to ANSYS workbench simulation module. Forged steel has been used as material for crank shaft.
Crank Shaft In Ansys VII.
DESIGN CALCULATION FOR CRANK SHAFT
Here, Capacity of engine=3785.1cc No of cylinders= 4 Bore*stroke=97mm*128mm Compression ratio=18:1 Maximum power=100hp Maximum torque=475Nm N=2300rpm Weight of flywheel=800N Maximum gas pressure=2.5N/mm2
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International Journal for Research in Applied Science & Engineering Technology (IJRASET) ISSN: 2321-9653; IC Value: 45.98; SJ Impact Factor: 7.429 Volume 8 Issue V May 2020- Available at www.ijraset.com A. Design Of Crankshaft When The Crank Is At TDC Of Piston Where Maximum Bending Moment Occurs Let D = piston diameter or cylinder bore in mm Design reaction Force acting on piston Pp= πD2/4*Pmax = π*(97)2/4*2.5 =18474.53N Assume that distance (b) between the bearing 1 and 2 is equal to twice the diameter of piston (D) b1=b2=194/2=97mm By symmetry (R1) v= (R2)v=Pp/2=18474.53/2 =9237.27N Similarly it is assumed that c1= c2=c/2 We know due to the weight of flywheel acting downward there will be two Vertical reaction V2 and V3 at bearing 2 and 3 respectively such that (R2’) v= (R3) V=W/2=600/2=300N And due to the resultant belt tension (P1+P2) acting horizontally then will Be two vertical reaction V2 and V3 at bearing 2 and 3 respectively, such that (R2’) v= (R3’) v=w/2=600/2=300N And due to the resultant belt tension (P1+P2) acting horizontally then will be two horizontal reaction (R’2) h and (R’3) h respectively Therefore (R2’) h= {(P1+P2)/C}*C1= {(P1+P2)/C}*C/2 = (P1+P2)/2 =1000/2 =500 N Now the various parts of the Crankshaft are designed such as B. Design of Crank pin Let dc = Diameter of Crankpin in mm σb = Allowable bending stress for the crank pin = 75 N/mm2 Pb = allowable bending pressure at the crank pin = 10 N/mm2 We know that the bending moment at the centre of crankpin (Mb) c = (R1) v * b1 = 9237.27*97 = 896.015*10^3 N-mm From data book (Mb) c= (πdc^3/32) = π*dc3/32*75 Dc^3=121689.7846 Therefore dc=49.55 or 50mm Assumption : Let (l/d) ratio of crank pin bearing is 1 (Lc/dc)=1 Lc=dc=50mm Pb=Pp/dclc=18474.53/50*50=7.39Nmm^2 Therefore Pb<100Nmm^2 Design of left hand crank web Let w=width of crank web (mm) t=thickness of crank web (mm) The empirical relationship is as follows (from V.B Bhandari) t=0.7dc=0.7*50=35mm
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International Journal for Research in Applied Science & Engineering Technology (IJRASET) ISSN: 2321-9653; IC Value: 45.98; SJ Impact Factor: 7.429 Volume 8 Issue V May 2020- Available at www.ijraset.com w=1.14dc=1.14*50=57mm The direct compressive stress is given by σc = (R1) v/ (w*t) =9237.27/ (35*57) = 4.63 N/mm2 Compressive stress due to bending moment σb = {6*(R1) v*[b1-l/2-t/2]}/w*t^2 = 21.19 N/mm2 Therefore Compressive stress (σc) t= σc+σb = 4.63 + 21.19 = 25.82 N/mm2 The total compressive stress is less than that of allowable bending stress 75 N/mm2 and the design of crank web is safe. VIII. MESHING For meshed the crank shaft tetrahedron element has been selected. The total number of nodes and the total number of elements are obtained as shown in figure.
IX.
RESULT FOR ANALYSIS OF CRANK SHAFT
Structural Analysis, Strain For Material 1
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International Journal for Research in Applied Science & Engineering Technology (IJRASET) ISSN: 2321-9653; IC Value: 45.98; SJ Impact Factor: 7.429 Volume 8 Issue V May 2020- Available at www.ijraset.com
Total Deformation
Structural Analysis, Stress For Material Number 2 Table 2: Result For Conventional Material Forged Steel MIN Total Deformation 0 Equivalent elastic strain 7.644e-9 Equivalent Stress 1.567e-3
Total Deformation Equivalent Elastic Strain Equivalent Stress
Table-3: Result For Composite Material MIN 0 8.89e-9 1.868e-3
MAX 0.16613 9.3e5 19.076
MAX 0.016298 8.82e-5 18.521
Table-3: Weight Of Forged Steel And Composite Material Crank Shaft Material Weight(kg) Forged Steel 3.8228 Metal Matrix Composite 2.1635 X.RESULT A. B. C. D.
Diameter of crankpin=50mm Length of crankpin=24mm Diameter of the shaft=125mm Web thickness=23mm
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International Journal for Research in Applied Science & Engineering Technology (IJRASET) ISSN: 2321-9653; IC Value: 45.98; SJ Impact Factor: 7.429 Volume 8 Issue V May 2020- Available at www.ijraset.com REFERENCE [1] [2] [3] [4] [5] [6]
M. Reddy, R. Prasad, M. Uday Reddy, L. KUMAR, Design & analysis of crankshaft by forged and composite material, International Journal of Engineering Trend and Technology (2017). V. Karandikar, P. Deshpande, N. Patil, D. Ronge, Design & analysis of crank shaft, International journal of Engineering Research (2017). M. Srihari, S. Vijay Nirmala, Design & analysis of crankshaft, International Journal of Scientific Research and Mordern Education (2016). Mukund Hingne and Dr. Rashmi Dwlvedi, Design and Analysis of Crankshaft Usiging Ansys,(2018) S. Dev & K. Chaware,”Design and Analysis of Single Cylinder Petrol Engine Crankshaft using ansys,(2019) Sa Gupta, N.Mahesh and B.Dinesh Kumar, Design and Analysis of Crankshaft ,(2015)
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