Allowable stress
Joint shear stress
Minimum step depth
Strength check
σ ≤ σ A
Design of optimum step depth
Anticipates that a joint is designed so that any breakage occurs in the joint itself, and not in the basic material.
L opt = max {L min , L 1 }
where:
and the joint factor f: |
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for h 1 < h 2 : |
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for h 1 > h 2 : |
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Meaning of used variables for metric units:
S US |
Joint strength in shear [MPa] |
k S |
Shear safety factor |
S Ub |
Tensile strength of basic material [MPa] |
d |
Diameter of inner tube or step diameter [mm] |
L |
Step depth [mm] |
h 1 |
Tube thickness of inner tube [mm] |
h 2 |
Tube thickness of outer tube [mm] |
Meaning of used variables for English units:
S US |
Joint strength in shear [psi] |
k S |
Shear safety factor |
S Ub |
Tensile strength of basic material [psi] |
d |
Diameter of inner tube or step diameter [in] |
L |
Step depth [in] |
h 1 |
Tube thickness of inner tube [in] |
h 2 |
Tube thickness of outer tube [in] |