Deformation and bending moment mitigation through quasi-static adjustment in scissor structures

Scissor structures are widely employed in civil, mechanical, aerospace, and other engineering applications. Although studies have been conducted on their geometrical precepts, including straight, curved folding, and unfolding, researchers have underestimated the effect of bending moment on scissor structures. In a loaded scissor structure, one of the major problems is the significant moment in shear connectors due to the difference in axial forces in the coupled macro-element members. In this study, the bending moment is mitigated to a desired limit. It is done in two ways: first, by providing cables at effective locations to mitigate bending moments and deformation, and second, by providing a novel formulation that adjusts the bending moment by changing the lengths of some effective members using turnbuckles. An optimization algorithm is used to minimize the total change in member length. Several examples are provided, including a large-span scissor structure. The study was conducted in MATLAB, and the results were verified through nonlinear analysis in SAP2000. The results show that the bending moment and deformation can be reduced by 90% by attaching cables. In addition, the presented formulation can determine the minimum member length change required to adjust the bending moment in all structural members within a specified domain.