This Aerospace Information Report (AIR) establishes flexure test procedures to determine and classify the fatigue strengths of reconnectable or permanent hydraulic tube joints.

The procedure is intended for conducting flexure tests of fittings and joints for hydraulic tubing materials such as AMS 5561 steel, AMS 4944 titanium and MIL-T-7081 aluminum alloy, mounted as free-free resonant beams.

Of particular advantage are the inherent simplicity of test setup, minimum restraint from a test fixture, low power requirements, short test duration, and ease of varying stress level.

Classification:

Type:

Type I Tests to be conducted with full cyclic bending stress reversal without simultaneous application of internal pressure

Type II Tests to be conducted with full cyclic bending stress reversal with a constant mean stress applied by imposing system pressure during cycling