L - 7 More Forces in Machining

# L - 7 More Forces in Machining - More Forces in Machining...

This preview shows pages 1–12. Sign up to view the full content.

More Forces in Machining Lecture 7 ME1800

This preview has intentionally blurred sections. Sign up to view the full version.

View Full Document
objectives Derive direction cosine matrix for force transformation Review relations between machining forces
Machining forces and Friction α sin cos c t F F F + = sin cos t c F F N - = φ sin cos t c s F F F - = cos sin t c n F F F + = Rake face Frictional force and normal force Shear plane forces F t F n F c F s N F = = τ μ tan tan tan t c c t F F F F - + = Tool workpiece friction coefficient µ

This preview has intentionally blurred sections. Sign up to view the full version.

View Full Document
Force relationships Pythagorean (N 2 +F 2 ) ½ = (Fc 2 +Ft 2 ) ½ = (Fs 2 +Fn 2 ) ½ = P α α Fc Ft F N P tool Axes rotation – direction F = Fc cos(90-α) +Ft cos α N = Fc cos (α) + Ft cos(90+α) cos(90-α) = sin α cos(90+α) = -sin α F = Fc sin α +Ft cos α N = Fc cos (α)- Ft sin α
Axes rotation α α Fc Ft F N tool α 90- α N = Fc cos α + Ft cos(90+α) F = Fc cos(90- α) +Ft cos α cos(90-α) = sin α cos(90+α) = -sin α N = Fc cos (α)- Ft sin α F = Fc sin α +Ft cos α Two orthogonal force systems Fc and Ft N and F

This preview has intentionally blurred sections. Sign up to view the full version.

View Full Document
Friction coefficient and friction angle Friction coefficient = tangential/normal = F/N = µ Friction angle = atan F/N = atan µ = τ α F N tool α τ
Friction angle, τ, to shear angle, Ф Merchant Equation (in degrees)

This preview has intentionally blurred sections. Sign up to view the full version.

View Full Document

This preview has intentionally blurred sections. Sign up to view the full version.

View Full Document

This preview has intentionally blurred sections. Sign up to view the full version.

View Full Document
This is the end of the preview. Sign up to access the rest of the document.

## This note was uploaded on 04/29/2008 for the course ME 1800 taught by Professor Brown during the Winter '08 term at WPI.

### Page1 / 12

L - 7 More Forces in Machining - More Forces in Machining...

This preview shows document pages 1 - 12. Sign up to view the full document.

View Full Document
Ask a homework question - tutors are online