Fatigue Crack Growth of Steel and Aluminum Alloy Specimens under Mode II Loading

The behavior of fatigue crack growth under mode II loading has been investigated on steels (JIS SPCC and SM 50B) and aluminum alloys (7075-T6 and 2017-T4). Tests were made by a specially designed apparatus under various combinations of ⊿KII and KIS, where ⊿KII is the range of the repeated mode II loading and KIS is the statically applied KI. Under mode II loading, two modes of fatigue crack growth, mode II growth and tensile mode growth, were usually observed, though in some cases only one was observed. Here, mode II growth and tensile mode growth mean the fatigue crack growth in the plane of precrack and that in the plane which makes about