Sheet metal Forming BY RAVI SINGH CHOUDHARY
GATE syllabus Load estimation for Sheet metal forming process Shearing: Blanking & Punching Deep drawing Bending
0 When the metal is deformed, it is first elastically deformed and then plastically. When applied load is removed, the plastic component of the deformation remains permanent while the elastic part springs back to its original shape.
Stress - Strain diagram Stress, strain curve Unloadingi Loading Strain Permanent deformation Springback The amount of spring back is the property of the material which depends on the modulus of elasticity. Higher the modulus of elasticity, lower would be spring back.
Shearing V, F Punch Plastic deformation = stock thickness c = clearance Die v, F Penetration Fracture
Shearing v, Penetration Tensile Compressive
Clearance Punch C = 0.0032*t*VT Total clearance will be 2C t = stock thickness | |+ c = clearance Die
Blanking and Punching Punch Starting stock produced by shearing operation from a big metal sheet Washer Scrap Blank Blanking Punching Steps in production of washer
Blanking and Punching In shearing operation, first the material is elastic deformed then plastic... After the final breaking slug will spring back to bigger size. This will make the blank cling to die face, unless angular clearance is provided.
Blanking Punch diameter= Die diameter-2C Diameter of die Diameter of blank Clearance should be on punch
End of session Thank ou