FIGURE NUMBER
LEGEND
PAGE NUMBER
11
Micro-Probe Evidence of Sulfur
(a) Freshly exposed steel surface
(b) Near lip of pre-existent crack
38
12
Cleavage Fracture in Hanger U17 - C17 N
(a) Normal view showing paint in upper left and longitudinal crack in center
(b) Oblique view showing evidence of torsion
41
13
Cleavage Fracture in Chord L12 - L13 N
(a) Crack origin at rivet hole
(b) Reflective specks in south channel
43
14
Rivet Fractures in Hanger Connection at U13 N
44
15
Eyebars with Gage Locations and Initial Cut Lines
48
16
Circumferential Stress Contours for Initial Cuts, Specimen B-17
49
17
Radial Stress Produced by Layer Removal, Specimen B-17
50
18
Fracture Toughness Test Arrangement for 0°F Temperature
51
19
Specimen Configuration with Strain-Gage Locations for Full-Scale Fracture Test
53
20a
Room-Temperature Fatigue-Crack-Propagation Rates for Eyebars Material
55
20b
Effect of Temperature and Environment on the Fatigue-Crack-Propagation Rates for Eyebars Material
56
21
Test Setup for Wedge-Force Loaded Specimens under Environmental Conditions
59
22
Microprobe Area Scans at Site A
61
23
The Effect of Strain Rate on the Three-Point Bend Properties of A-7 Steel Charpy V-Notch Specimens
63
24a
Appearance of Freshly Opened Crack in Eyebars Steel
67
24b
Fracture Regions in Freshly Opened Crack in Eyebars Steel
67
25
Appearance of Branch and Secondary Cracks Associated with Fracture in Eyebars No. 330
69
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