【作者】 孟祥剑； 方辉；

【Author】 MENG Xiang-jian;FANG Hui;Department of Ocean Engineering, Ocean University of China;

【机构】 中国海洋大学工程学院；

【摘要】 高比刚度高负载桁架结构受扰动后持续低衰减振动,将加剧结构疲劳乃至破坏。本文设计了一种高比刚度撑杆,其中将可变边界钢制压杆内置于铝质圆壳;有限元模拟循环载荷作用,金属圆壳总处于线弹性状态,可变边界压杆稳态则随载荷循环跳变,该类撑杆力-位移关系具有初始高刚度,整体上形成滞后回环;同时,发展了层合结构弯曲与压杆稳定分析方法,给出了该撑杆结构参数与其屈曲、后屈曲及滞后特性间的解析关系。将该撑杆用于典型铝质桁架,结构整体比刚度与全铝桁架接近,有限元模拟扰动下桁架自由衰减,采用新型撑杆桁架振动频率与传统弹塑性结构一致,衰减速率则数倍于传统弹塑性结构,新型撑杆保持高比刚度同时为桁架提供了高阻尼性能。更多还原

【Abstract】 The truss with high specific stiffness and high load capacity is prone to generate low attenuation vibration after being disturbed, aggravating the structural fatigue until destroy. In this paper, a novel brace with high specific stiffness is designed, in which steel column with a variable boundary is placed in round shell comprised by aluminum. A cyclic load simulated by finite element method is applied to the novel brace. As the cyclic load changes, the steel column produces jump phenomenon, but the round shell always maintain linear elastic state. The relationship between force and displacement under cyclic load creates a hysteresis loop with initial high stiffness. Meanwhile, the bending of laminated structure and stability analysis method of the steel column is developed to confirm the analytical relation of structural parameters and its buckling, post-buckling and hysteresis characteristics. A novel truss is built by embedded multiple novel braces in a typical aluminum truss, which specific stiffness is close to aluminum truss. Subsequently, free vibration analysis of novel and typical truss is implemented via numerical simulation under the disturbance. The results show that the attenuation velocity of novel truss is several times that of typical truss. However, the inherent frequency for two kinds of structure maintains the same. It concludes that the novel brace provides high damping capacity for truss structure without affecting the high specific stiffness.更多还原