Approximations in optimization of damage tolerant structures

Approximations for structural response and design sensitivities significant ly reduce the computational cost of structural optimization. To be useful, the approximation must be accurate and computationally efficient. Damage to lerant design puts even more stringent computational demands on optimizatio n procedures and approximations due to the large structural changes inheren t in damage. A robust approximation is evaluated and extended to include de sign sensitivities. It is implemented in an optimization procedure and test ed. It is shown that this approximation is accurate and efficient for damag e tolerant optimum design of complex structural models. Last, a qualitative measure is developed and tested that estimates the computational savings u sing these approximations.