3.3. Simpson’s Ist rule

Unit 3 - Design procedure

3.3. Simpson’s Ist rule

These rules are widely applied in Naval Architecture. They are a special case of the Newton’s cotes rule.
Let us deduce a rule for integrating a curve Y over the extent of x. It will be convenient to choose the origin to be in the middle of the base 2 h long having ordinates Y1, Y2 and Y3. The choice of origin in no way affects the result.
s

Assume that the curve can be represented by an equation of the third order.

1


s






r



e



This is the generalized form of the first rule applied to areas. The common multiplier is 1/3 x the common interval “h” and the individual multipliers are 1,4,2,4,2,4,2,4,1
The rule is one for evaluating an integral. It is equally applicable to any integration using Cartesian or polar co-ordinates.
It is suitable for 3, 5, 7, 9, 11, 13 ... etc ordinates

Last modified: Saturday, 30 June 2012, 7:11 AM