Fail-Safe Optimal Design of Structures with Substructuring.

Abstract : The problem of fail-safe structural design is defined. An optimal design formulation for the problem is developed with substructuring. An optimal design algorithm based on the state space gradient projection method is derived. Optimal designs for several cases of an open and closed tail-boom structures for the Army Cobra helicopter are obtained and analyzed. Constraints are imposed on stresses, displacements, buckling, natural frequency and member sizes. A user's manual for a computer program based on the algorithm is also described. (Author)