Structures and Materials Characterization Under Service Conditions

Optical micrometers are used to determine crack length in fatigue crack growth rate tests.

The Structures and Materials Evaluation group evaluates the durability of materials and manufactured components. We have the ability to determine the mechanical properties and endurance of materials and structures under a wide range of service conditions and environments.

We have the experience and facilities to perform standard material tests to characterize the mechanical properties in accordance with the procedures of ASTM, SAE, or ISO standards where applicable.  Material properties are typically determined by techniques equivalent to or more rigorous than requirements imposed by ASTM methods.  Examples of standard tests include yield and ultimate stress, modulus, elongatioin, fatigue crack growth rate, fracture toughness, shear modulus, and fatigue life.

We frequently develop unique test procedures that satisfy a customer's needs when standard procedures are non-existent.  Drawing from a wealth of experience, we are adept at constructing one-of-a-kind test setups to simulate component installations and field conditions.

Laboratory Capabilities

• Closed-loop, servo-hydraulic test systems for superior control during testing
• Load frames and T-slot tables for a wide variety of load configurations
• Uni-axial loading up to 220,000 lb
• Test speeds up to 300 in/sec closed loop, and 1,000 in/sec monotonic
• Torque from 25 in-lb to 75,000 in-lb
• Torsional test rates of 500°/sec up to 5,000 in-lb and 100°/sec up to 70,000 in-lb
• Environmental chambers for temperatures from -320°F to 2,000°F
• Testing environments such as lab air, high humidity air, corrosive atmospheric environments, and solution baths
• Pressures from ambient to vaccuum (10-5 torr)
• Multi-axial testing

Most of this work is carried out in the Structural Test Laboratory, and is supported by other facilities in the Research Institute such as the Metallography Lab, the Surface Analysis Lab, Composites Lab, and the Machine Shop.