Sheet metal Forming BY RAVI SINGH CHOUDHARY
GATE syllabus Load estimation for Sheet metal forming process Shearing: Blanking & Punching Deep drawing Bending
Bending Metal stretched Neutral axis plane Neutral axis Metal compressed Bend axis- Bending is a manufacturing process that produces a V-shape, U- shape, or channel shape along a straight axis in ductile materials, most commonly sheet metal.
Bending Bend allowance, When the sheet metal is put through the process of bending the metal around the bend is deformed and stretched. As this happens you gain a small amount of total length in your part. Likewise when youa trying to develop a flat pattern you will have to make a deduction from your desired part size to get the correct flat size. L,- (r+kt) r>2t, k = 0.5 r<2t, k = 0.33 Where, r = bend radius k constant (stretch factor) t thickness of material bend angle (in radian)
Spring back Springback Dimensional change of the formed part after releasing the pressu forming tool due to the changes in strain produced by elastic recovery Weld stress T Elastic modulus Spring back T Springback is encountered in all forming operations, but most easily occurs in bending
Bending force Punch 1 Bend length width of stock (mm) w = width of die-opening (mm) K die-opening factor (will be given in the question) HU For U or channel bending force required is double than V - bending For edge bending it will be about one-half that for V - bending
Defects in Drawing Wrinkle Fracture Earing miss strike Orange peel In sheet metal forming: Local necking or thinning or buckling and wrinkling in regions of compressive stress
End of session Thank ou