What are the common material testing methods in aerospace?

Material testing validates properties for design and quality. Mechanical tests: Tensile test - Strength, modulus, elongation, Poisson's ratio; Compression test - Critical for composites; Shear test - Interlaminar shear, bearing strength; and Fatigue test - S-N curves, crack growth rates. Hardness: Rockwell, Brinell, Vickers - Quality control, correlation to strength. NDT (Non-Destructive Testing): Ultrasonic - Internal defects, thickness, delaminations; Radiography (X-ray) - Porosity, inclusions, foreign objects; Eddy current - Surface/near-surface cracks, conductivity; Dye penetrant - Surface cracks in non-porous materials; and Magnetic particle - Surface cracks in ferromagnetic materials. Specialized: Fracture toughness (KIc) - Critical stress intensity; Stress corrosion - Time-to-failure under stress; and Environmental - Effects of temperature, humidity. Test standards: ASTM, SAE AMS, MIL-specifications ensure consistent methods. Test results feed into design allowables databases.