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

Figure 14

Typical fracture images (stress amplitude = 155 MPa and stress ratio = 0). (a) Macroimage. (b) Micrograph of fatigue initiation zone. (c) Micrograph of fatigue crack propagation zone. (d) Micrograph of fast fracture zone.

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