Optimal design of large structures for damage tolerance

The basic idea presented herein is that a systematic method for optimal structural design can be developed that accounts for probable future damage to the structure. A general mathematical model for the damage-tolerant structure design problem is defined. Design sensitivity analysis and procedures for treatment of a large number of constraints for the problem are presented. As a practical design example, damage-tolerant design of an open truss helicopter tail-boom structure is considered. Optimal designs for several cases of the tail-boom are presented. It is shown that considerable design variation is necessary to achieve the damage-tolerant design objective. It is also shown that if the structure is optimized without consideration of damage, the structure will fail catastrophically when any damage occurs to the structure.