2. Studies at the Battelle Memorial Institute
PAGE
a. Non-destructive search for eyebar flaws
46
b. Residual stress investigations
46
c. Fracture toughness of eyebar steel
47
d. Crack growth rates due to fatigue, hydrogen-stress cracking and stress-corrosion
54
e. Fractographic examination of freshly open crack
58
f. Fracture toughness of A7 steel
62
3. Investigations at U. S. Steel Applied Research Laboratory
64
a. Chemical and mechanical tests of eyebar steel
64
b. Slow bend test of eyebar steel
65
c. Depth of pitting in eyebar No. 33
65
d. Fractographic analysis of freshly opened crack
66
4. Laboratory Tests at Structures Laboratory, Fairbank Highway Research Station, Federal Highway Administration
68
a. Fatigue tests of eyebar steel
70
b. Scale model tests of eyebar joint C13N
70
5. Investigations of the Possibility of Fretting-Fatigue by Professor W. L. Starkey of Ohio State University
78
6. Static Tests of a Full-Scale Eyebars at Lehigh University
79
D. Status of Bridge Inspection and Maintenance
82
IV. ANALYSIS
84
A. The Properties of the Steels in the Point Pleasant Bridge
84
1. Chemical analysis of A7 steel of various laboratories compared
85
2. Mechanical tests of A7 steel of various laboratories compared.
85
3. Chemical analysis of eyebar steel
87
4. Mechanical tests of eyebar steel
87
5. Fatigue properties of eyebar steel
88
B. Actual Stress Levels in Various Components of the Structure as Compared to Primary Stress Analysis
89
1. Significance of secondary stresses
89
2. Stresses induced by wind excited oscillations
90
3. Stress concentrations in the eyebar head
91
C. The Mechanism of Collapse as Determined by the Process of Elimination
93
1. Elimination of causes other than fracture in eyebar No. 330
94
2. The fracture of eyebar No. 330
94
3. Mechanism of flaw growth to critical size
95
D. Compatibility of Established Mechanism of Failure with Observed Facts and Witness Testimony
100
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