“…5(b) for cables, one bent to the left and one bent to the right. This is associated with a double jumping phenomenon (Chen et al,2014;Guo et al, 2016) in the frequency response diagrams, which is triggered by those saddle-node bifurcations, i.e., SN1, SN2. Actually, it can be deduced that there exists two saddle-node bifurcations at the left and right side beyond the range [-1.5,1.5] of σ1, respectively.…”