The behavior of GFRP-stiffened and -unstiffened shells under cyclic axial loading and unloading

Abstract

The results of an experimental study on the cyclic axial loading and unloading behaviors of thin-walled GFRP cylindrical shells are presented. Each specimen was tested first under pure axial compression until the first visible damage occurred, At that point, loading stopped and the unloading step started until the load returned to zero. Based on the results, it seems that for cyclic loading, using stiffened shells is better than using unstiffened shells. On the other hand, the damage growth in the stiffened shells is slower than in the unstiffened shells. For aerospace and aircraft structures, which have been using cyclic axial loading, it seems that composite structures with composite helical stiffeners are better than unstiffened composite structures.