Model
Digital Document
Publisher
Florida Atlantic University
Description
Constant deflection fatigue experiments performed on cathodically
protected, notched steel bars in natural sea
water produced stresses which caused short cracks to appear
soon after the beginning of testing . At stresses
above 22 ksi (152 MN/m^2), cracks grew continuously across
the bars. At stresses below 22 ksi (152 MN/m^2), and at
potentials of -1.20 volts , saturated calomel electrode SCE,
cracks did not grow, or arrested part way across the bar.
At potentials other than - 1.20 volts , SCE, stress levels
had to be less than 19 ksi (131 MN/m^2), before crack growth
could be arrested. Strain gage readings suggest calcareous
material may be forming on the fracture surfaces of cracks
in which growth was arrested. Examination of these surfaces shows a pattern of calcareous deposit and corrosion
product which suggests a potential gradient within the
crack electrolyte. A mathematical model is presented
which describes this potential gradient.
protected, notched steel bars in natural sea
water produced stresses which caused short cracks to appear
soon after the beginning of testing . At stresses
above 22 ksi (152 MN/m^2), cracks grew continuously across
the bars. At stresses below 22 ksi (152 MN/m^2), and at
potentials of -1.20 volts , saturated calomel electrode SCE,
cracks did not grow, or arrested part way across the bar.
At potentials other than - 1.20 volts , SCE, stress levels
had to be less than 19 ksi (131 MN/m^2), before crack growth
could be arrested. Strain gage readings suggest calcareous
material may be forming on the fracture surfaces of cracks
in which growth was arrested. Examination of these surfaces shows a pattern of calcareous deposit and corrosion
product which suggests a potential gradient within the
crack electrolyte. A mathematical model is presented
which describes this potential gradient.
Member of