Quasi-Dynamic Stress Analysis on Crank Shaft of Computerized Variable Compression Ratio (VCR) Diesel Engine
|International Journal of Engineering Trends and Technology (IJETT)||
|© 2015 by IJETT Journal|
|Year of Publication : 2015|
|Authors : B.Nagaraju, J. Sampath Kumar, M.S.S.Srinivasarao, K.Naresh Kumar
|DOI : 10.14445/22315381/IJETT-V30P239|
B.Nagaraju, J. Sampath Kumar, M.S.S.Srinivasarao, K.Naresh Kumar"Quasi-Dynamic Stress Analysis on Crank Shaft of Computerized Variable Compression Ratio (VCR) Diesel Engine", International Journal of Engineering Trends and Technology (IJETT), V30(4),204-211 December 2015. ISSN:2231-5381. www.ijettjournal.org. published by seventh sense research group
The main objective of this study was to investigate the stresses induced in crankshaft manufactured of AISI E4330 forged steel & an aluminium alloy (7076-T6). A comparative analysis was made to study the behaviour of materials. Crank shaft is one of the most important moving part with a complex geometry in internal combustion Engine. It converts the reciprocating displacement of the piston into a rotary motion. When combustion takes place in the engine, there by high temperature and pressure will be developed inside the engine cylinder. Due to high speed and at high loads, the piston is subjected to large structural stresses, which influences on the crank. Experimentation was carried out on a Computerized Variable Compression Ratio (VCR) Diesel Engine Test Rig at Compression ratio of 16.5 for obtaining he results. The obtained results were tabulated for knowing pressure at various crank angles. The results were analysed by drawing the Pressure vs. crank angle variation diagram. The dynamic analysis was carried out by developing the equations of equilibrium from the Free Body Diagrams of individual components of Slider-Crank Mechanism. The forces induced at the pin joints and inertia forces obtained from the dynamic analysis were used as input for further analysis. A three dimensional model of diesel engine crankshaft is developed by using SOLID WORKS software. And further analysis is carried out by using ANSYS WORKBENCH 15.0 software. Dynamic analysis parameter solving by MAT Lab. These reaction forces are applied along with boundary conditions on the FE model of crank shaft. The stress analysis was performed at critical crank angles of rotation. Finite element analysis which consists (1) stress analysis (2) Modal analysis and (3) fatigue analysis. The structural analysis involves determination of induced stresses and deformation for all crank angles at crank pin and bearing supports. The results in the form of von-Mises stresses and deformation were determined for both materials. Further the crank shaft is also subjected to modal and fatigue analysis for maximum load condition 3650, from the modal analysis observed different mode shapes of crank shaft and also factor of safety observed from the fatigue analysis. The results obtained from the structural analysis shows that the stresses induced at crank pin and bearing supports in aluminium alloy (7076-T6) are lesser in comparison with AISI E4330 forged steel for various different crank angles. The results obtained from modal analysis were inferred that aluminium alloy (7076-T6) exhibits lesser frequency in comparison with AISI E4330 forged steel for different mode shapes. The fatigue analysis carried out to know the factory of safety of the two materials for at 106 cycles. The comparative results shows that the aluminium alloy (7076-T6) exhibits better results in comparison with AISI E4330 forged steel.
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