Constraints

Having choosen the design variables , the next task is to identify the constraints associated with the optimization problem.The constraints represents some functional relationships among the design variables and other design parameters satisfying certain physical phenomenon and certain resourse limitations. Some of these considerations require that design remain in static , dynamic equilibrium.The nature and number of constraints to be included in the formulation depend on the user.There are usually two types of constraints that emerge from most considerations.Either the constraints are of an in equality type or of equality type. Inequality constraints states that the functional relationships between the design variables.are either greater than or ,smaller than, or equal to,a resource value.

the stress d(x) developed anywhere in a component must be smaller than or ,equal to allowable strengthof the material.

Mathematically

d(x)<=Sallowable.

Equality constraints sate that that the functional relationships should exactly match the resource value.

d(x)=Sallowable.

Equality constraints are usually difficult to handle and,there to be avoidable wherever possible.If the functional relationships of equality constraints sre simpler ,it may be possible to reduce the number of design variables by using the equality constraints.
previous