Anyone have experience with Section 12 Vibration Test of ISO 19879?
Seems straight forward but description is a bit confusing:
Pressurize to working pressure
Apply bending stress level to 25% of the minimum yield strength of the tube.
Section 12.2.5 states, "apply a bending load to the end of the tube opposite to the strain gauge until the combined axial stress is 25% of the minimum yield strength of the tube."
The axial stress due to the pressure reacting to the closed tube end is very small. But the strain gage will react to the Poisson's effect which is a negative strain.
My quesitons:
What size strain gauge is used? Standard only shows the position relative to the connector.
Do you ignore the effect of pressure and set the test strain test level to the equivalen to 25% of yield strength, or include the Poisson's strain plus the 25% yield strain?
The standard says "combine axial stress." The Poisson's effect is not a stress. It's an axial strain resultant from a hoop stress via the biaxial stress strain relationship.
Thoughts?
Thanks!
Seems straight forward but description is a bit confusing:
Pressurize to working pressure
Apply bending stress level to 25% of the minimum yield strength of the tube.
Section 12.2.5 states, "apply a bending load to the end of the tube opposite to the strain gauge until the combined axial stress is 25% of the minimum yield strength of the tube."
The axial stress due to the pressure reacting to the closed tube end is very small. But the strain gage will react to the Poisson's effect which is a negative strain.
My quesitons:
What size strain gauge is used? Standard only shows the position relative to the connector.
Do you ignore the effect of pressure and set the test strain test level to the equivalen to 25% of yield strength, or include the Poisson's strain plus the 25% yield strain?
The standard says "combine axial stress." The Poisson's effect is not a stress. It's an axial strain resultant from a hoop stress via the biaxial stress strain relationship.
Thoughts?
Thanks!
