cutting forces(static) simulation on lathe

Machine tool(LATHE)

TALIYA HEMANTH 2012ABPS451H

MRUDUL NEKKANTI 2012ABPS525H

KONREDDY VARUN KUMAR REDDY 2012ABPS828H

SURYA TEJ BODDU 2012ABPS953H

MATERIAL SELECTION:

Any machine tool must be designed in such a way that it bears all the three important loads i.e,

Tension

Bending stress

Torsion

The weight of the bar is inversely proportional to the quantity E / ɤ , is known as unit stiffness of the material in tension. The larger the unit stiffness of a material, the smaller is the weight of the structure required to ensure the deflection of the structure due to a particular given load does not exceed a specified value

Material E. kgf/cm2

ɤ. kgf/cm3 E / ɤ

LOW carbon steel 2.0*106 7.8*10-3 2.56*108

Medium carbon steel 2.1*106 7.8*10-3 2.69*108

Alloyed steel 2.1*106 7.8*10-3 2.69*108

Grey cast iron 1.2*106 7.2*10-3 1.66*108

Duraluminium 0.75*106 7.8*10-3 2.68*108

Property Steel Relation Cast iron

Strength steel > cast iron

Rigidity steel > cast iron

Wall thickness needed steel < cast iron

Casting steel < cast iron

Economy steel < cast iron

Part Material

Bed Grey cast iron

Head stock Steel

Tail stock Steel

Cross slide Steel

Carriage Grey cast iron

Tool post Steel

Pro-E model

Machine specifications Length =1.542m

Width=0.43m

Maximum work piece dimensions= 50mm*550mm(cylindrical)

Factor of safety =2.5

Materials used =grey cast iron and steel , aluminum alloy .

Cutting forces We basically look at turning operation on lathe machine and we tried to calculate the forces for appropriate depth of cut and feed of the cutting tool.

Depth of cut=3mm

Feed =2mm/rev

Forces acting on the tool are ◦ Axial(Fa)◦ Tangential(Ft)◦ Radial(Fr)

Cutting forces calculation

Axial force= 2mm*3.14*50mm*1500

=805N

Calculated from the merchant circle diagram with a side rake angle of 8 and back rake angle of 6 degrees.

Radial force=315N

Tangential force=620N

Analysis Static analysis of the structure is made on the ANSYS “static structural” module.

The governing constraint conditions are

The base is fixed i.e no degrees of freedom for it.

The work piece is fixed onto the head stock and tail stocks rigidly.

There is no sliding between the parts .

Meshed Assembly

Stress distribution at tool-workpiece interface

Stress distribution at base

Stress distribution at Tail Stock

Stress distribution (cross section of tool)

Conclusion The lathe machine parts are assembled and are analysed for a real time machining operation like turning and is tested for stress distribution , deformation, and torsion are calculated for each part and the machine structure is allowable within the specified limits.