Fuzzy optimization of space frame

Fuzzy concepts are introduced into structural optimization to solve fuzzy optimization problems with a crisp objective function and fuzzy constraints, also a non-membership function is used to convert fuzzy constrains into crisp constrains. Two models are discussed where the objective function considered is the volume of space frame and the fuzzy constrains are design limits by the axial strength, slenderness, deflection, thickness and diameter of space frame member.