Experimental Study on Constant-Amplitude Fatigue Performance of Weld Toe in Steel Tube of Welded Hollow Spherical Joints in Grid Structures

Figure 13

Typical fracture images (stress amplitude = 123 MPa and stress ratio = 0.4). (a) Macroimage. (b) Micrograph of fatigue initiation zone. (c) Micrograph at 1 mm from the outer wall. (d) Micrograph at 2 mm from the outer wall. (e) Micrograph near the inner wall with 300 times. (f) Micrograph near the inner wall with 10000 times.

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