From Integrated Computational Materials Engineering to Integrated Computational Structural Engineering

Abstract

Recent advances in the simulation of the quench, cold-work and machining processes for large aluminum forgings are opening the way for a new paradigm in the design, manufacture and sustainment of aircraft structures. The use of large forgings permits the unitization of smaller parts (brackets, fittings, lugs, etc.) with primary structural components like spars and bulkheads. This is being done in order to reduce part count, which in turn leads to significant reductions in manufacturing cost. Unitization can also translate into weight reduction / avoidance when comparing against built-up structure, but it raises a number of issues for structural durability and damage tolerance, notably reduced repair / replace capability and reduced crack arrest capability. The viability of the unitization concept is dependent not only on the availability of material systems that retain their mechanical properties in very thick sections, but also on the designer’s ability to retain durability and damage tolerance, and to understand and mitigate the effects of residual stresses.