PSI - Issue 18

Evgeny Lomakin et al. / Procedia Structural Integrity 18 (2019) 549–555 Evgeny Lomakin and Boris Fedulov / Structural Integrity Procedia 00 (2019) 000–000

550

2

effects are experimentally studied for many structural alloys [1], which demonstrate the difference between the yield limits and the stress-strain diagrams for different stress states. One of the well-known examples of this type of materials is the rolled plate for further machining to get a final structural member. For the plastic limits of such material, there are an established terminology in the technical literature L, LT and ST, where we have introduced the indices of the mean direction of the samples tested along the rolling and in the plane of the rolled plate, as well as normal to the rolled plane, respectively (Fig. 1).

Fig. 1. Rolling plate anisotropy directions.

The values of yield limits of rolled plates and sheets of structural alloys are usually different depending on the direction of the cut samples [2, 3] (Fig. 2). Moreover, the yield stress is sensitive to the type of loading, for example, yield stress and hardening curves themselves are generally different for tension and compression (Fig. 3). For the selected alloys, in the case of rolled products, this sensitivity is most noticeable in the direction normal to the rolled surface (ST).

Fig. 2. Stretching diagrams in different directions for the plate (alloy B95)