Questions and All Correct Answers.
Load path redundancy requires what? - Answer 3+ members
What is required to use internal or system redundancy to remove NSTM bridge status - Answer
FHWA Approval
Brittle failure likelihood is increased by what? - Answer Cold temps, high load rates and rigid
constraints
Low toughness is analogous to? - Answer Brittleness
Charpey V Notch tests what? - Answer Toughness
What is toughness? - Answer Ability to resist fracture and crack propagation
List the welds in order of least to greatest fatigue susceptability - Answer
Silver Bridge - Answer Eye Bolt Failure, started NSTM review
Mianus River Bridge - Answer Pin and hanger failed from pack rust, introduction of hands on
requirement
Daniel W. Hoan Bridge - Answer Triaxial (CIF), Caused review for CIFs
I-35W Bridge - Answer Overloaded gusset plates, Gusset plates now considered NSTM
Sherman Milton Bridge - Answer T1 Steel butt weld failure
I-5 Skagit Bridge - Answer Impact Damage
I-276 Delaware River-Turnpike Toll Bridge - Answer Rivet hole filled with wellment started a
crack
, I-40 Hernando de Soto Bridge - Answer T1 Steel butt weld failure
Web Gap Details - Answer Gap left in stiffeners allowed for constrained induced fatigue and
out of plane distortion, 1985 mandated the connection of the flanges
NSTM member means what? - Answer Primary steel member at least partially in tension and
without load path redundancy
Load Path - Answer Deck, Super, Bearing, Sub, Foundation
Load Path Redundancy - Answer 3+ Members
Other two redundancies - Answer Internal and System
Properties of Steel - Answer Ductility, Toughness, Yield and Ultimate Strength, Modulus of
Elasticity
Ductility - Answer Ability to maintain load capacity under plastic deformation
What visual sign does brittle fracture lack? - Answer Shear lips
Brittle Fracture - Answer No warning prior to failure, sudden without strain
Ductile Failure - Answer Failure preceded by local plastic deformation, has shear lips
Triaxial Stress - Answer 3D stress state where deformation in any direction is restricted, AKA
brittle
Fracture Toughness - Answer ability of a material to resist crack propagation while under
load
Weld Quality Issues - Answer Porosity, Spatter, Under cutting, cratering
Weld Reinforcement - Answer Weld metal in excess of what was required to fill a groove.
ACTUAL THROAT -THEORETICAL THROAT
What kind of weld might use a backing bar? - Answer Single bevel groove weld