关键词: 可展桥；剪式机构；弦支体系；参数化分析；优化设计

Abstract: Scissor-like bridges can quickly build emergency channels after disasters and improve rescue efficiency. In view of the characteristics of poor stiffness and low material utilization of scissor-like elements(SLEs)， a new cable supported scissor-like deployable bridge(CSSDB)for emergency was proposed combined with cable supported system. In order to investigate the behavior of CSSDB， Karamba3D was adopted to establish the finite element model， and parametric analysis was carried out under the action of moving vehicle load， considering the struts’ length and numbers， the SLEs’ cross section， the initial prestress amplitude and the expansion angle. Besides， Galapagos was used to optimize the CSSDB with the minimum structural mass as the optimization objective. The results show that increasing struts’ number， struts’ length and initial prestress can effectively reduce the stress and deflection of SLEs， while the stress and deflection can be increased by increasing expansion angle. Increasing thickeness of SLEs’ cross section reduces stress and increases deflection instead， and the CSSDB’s performance is still dependent on bending of SLEs. The optimization reduces structural mass by 38.89%， and the stress and deflection of CSSDB are 0.25 and 0.2 times than that of the corresponding scissor-like bridge， which proves the superiority of the CSSDB.

Key words: deployable bridge; scissor-like elements; cable supported system; parametric analysis; optimization design