Manufacturing Technology Today

M. S. R. Niranjan Kumar ¹, M. M. M. Sarcar ², V. Bala Krishna Murthy ³, K. Mohana Rao ⁴

Affiliations
1 Prod. Engg. Dept., V R Siddhartha Engg. College, Vijayawada, IN
2 Mech. Engg. Dept., College of Engg., Andhra University, Visakhapatnam, IN
3 Mech. Engg. Dept., P V P Siddhartha Institute of Technology, Vijayawada, IN
4 C R Reddy College of Engg., Eluru, AP, IN

Abstract

Materials are put to serious test when they are subjected to elevated temperatures. Estimation of thermal stresses and deformations of fiber reinforced composite plates is more complex owing to material anisotropy, especially when they are subjected to combination, of mechanical and thermal loading. Hence an effort is made to study the thermo elastic behaviour of a cross-ply laminated composite skew plate with elliptical cutout subjected to pressure and non-linearly varying temperature loading in the present analysis. Major axis ofthe ellipse collinear with longer diagonal has been taken for the present analysis. A three-dimensional heat conduction analysis in fiber reinforced composite laminates has been simulated by finite element method to get realistic temperature in the laminate under different thermal boundary conditions. A finite element method, which works on the basis of three-dimensional theory of elasticity, is employed to evaluate the stresses and deformations. The results obtained by varying the skew angle and size of the cutout are discussed. The magnitude of the in-plane normal stresses and transverse deflection due to combined loading is greatly affected by the skew angle variation and their magnitude is observed to be minimum at higher value ofthe skew angle and at higher d/l ratio. The magnitudes of interlaminar stresses are observed to be minimum at lower d/l ratio.

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V. S. Parameswara Rao ¹, M. M. M. Sarcar ²

Affiliations
1 IPE Dept., K.L. College of Engg., Vaddeswaram, IN
2 Mech. Engg. Dept., A.U. College of Engg., Visakhapatnam, IN

Abstract

The WEDM has been found to have tremendous potential in its applicability in the present day metal cutting industry for achieving improved dimensional accuracy, surface finish, geometric features of work pieces (electrodes, dies etc.). However for successful utilization of process, optimization of various parameters is required for improving the productivity. In this regard an attempt was made to evaluate optimal parameters like discharge current, voltage at rated wire speed, tension, for different sizes of the prominent Die material, High Carbon-High Chromium steel. (HC-HCr tool steel) ranging from 5mm to 80mm. This work expresses the effects of the above mentioned process parameters on the criteria like cutting speed, surface roughness, spark gap (cutting off-set required) and specific energy consumption. The optimum values are evaluated at uninterrupted machining conditions with minimum wire rupture and breakage. Mathematical relations are explored at the optimum values for determining the cutting speed. Present work is useful in finding the cutting time for any size of the HC-HCr job and to set parameters for the required surface finish, corner radius with high accuracy of cutting.

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