How do you conduct a material selection trade study for an aircraft component?

Material selection balances multiple factors through structured evaluation. Process: Define requirements - Loads, environment, manufacturing, cost, weight; Identify candidates - Materials meeting basic requirements; Property comparison - Normalize properties for comparison (specific strength, etc.); Weighted evaluation - Score against criteria with importance weighting. Criteria typically include: Strength and stiffness (design drivers), Weight (specific properties), Damage tolerance and fatigue, Corrosion and environmental resistance, Manufacturing (machinability, formability, joinability), Cost (material, processing, lifecycle), and Availability and supply chain. Analysis: Ashby plots for property comparison, Trade studies for weight/cost, Manufacturing feasibility assessment. Selection validation: Prototype/test articles, Qualification testing, and Design allowables development. Documentation: Trade study report, selection rationale. Example: Fuselage skin might compare 2024-T3, 2524-T3, 7475-T7, and CFRP considering fatigue, damage tolerance, weight, and cost.