全金属支杆阵列多稳态被动转换及滞后阻尼特性

High stiffness and high hysteresis damping of metal column array in mutli-stable potentials

海洋结构趋向于更大型化,需以高刚度承担更大负荷,结构就不能很好地适应动态负载,动载低衰减传播将导致设备损坏和人员不适,但传统黏性阻尼减振结构的刚度较低,可能降低静态负载.为使减振结构同时具有高承载和高阻尼性能,本文基于稳定理论设计了多稳态被动转换支杆阵列,位移加载下压杆出现直杆-局部弯曲-整体弯曲3个稳定支撑状态,由此产生负刚度使激励-响应曲线形成滞后回环;进一步提出了线性弹簧-多稳态压杆并联结构,位移或力动态加载下该类结构都可发生多稳态转换,实现静态高刚度和动态高耗散,并以有限元模拟讨论了耗散特性的几何参数相关性.

Larger marine structures are being developed for deep-sea engineering.The structure with high stiffness is necessary in the designing,in which the dynamic responds propagate with low dissipation then bring detrimental effects on the equipment and staffs.However,most damping materials occupy the low stiffness and disadvantageous to load bearing.An eccentric column array with mutli-stable potentials is presented as an economical passive alternative for obtaining flag-shaped hysteretic damping combined with high stiffness.Negative incremental structural stiffness occurs when columns with capped ends are subjected to elastic buckling mode jump.Moreover,a system integration of mutli-stable and linear(positive stiffness)springs exhibits same properties compared to an individual mutli-stable element when force is controlled and loaded on the system.Then,stable axial dampers with initial modulus similar to that of the parent material and with enhanced damping were designed built and tested theoretically and numerically.