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Long-life fatigue tests have been performed on tubular nodular cast irontest specimens using uniaxial tension, torsion and equi-biaxial loading. Observed crackpaths were relatively straight for both the tension and torsion load cases but tortuouscrack paths were observed for equi-biaxial loading. Fatigue strength data arecompared to a Goodman-type fatigue limit criterion. The criterion includes a multiaxialstress state correction that is physically related to the growth of small cracks fromnotches and small defects. Experimental results obtained from fatigue tests on largethick-walled nodular cast iron structures tested in bending, torsion and combinedtorsion-bending loading are also presented. Observed crack paths were controlled byboth the loading type and the circumferential notch. A mean S–N curve for thecomponent was determined utilising the previously mentioned criterion in order tonormalize the test results which included different mean stress levels, principal stressratios and material strengths.