装备外壳结构周期设计及其振动特性

将声子晶体能带理论应用于装备外壳结构设计,把装备外壳圆柱壳段设计成周期结构。基于多子结构的双协调自由界面模态综合法,计算并对比了周期圆柱壳与非周期圆柱壳对弯曲振动的衰减特性。结果表明,周期圆柱壳中有弯曲振动强衰减带隙存在,而非周期结构中则没有带隙存在。进一步研究了轴向周期复合夹层材料圆柱壳的弯曲振动特性。同样,该周期复合夹层结构中依然有弯曲振动带隙存在,且在带隙频率范围内弯曲振动传播将受到明显的抑制。最后,考虑实际装备外壳形状,研究了含周期结构圆柱段的复杂装备外壳振动特性。研究表明,经过局部周期设计的复杂装备外壳保持了带隙特性,这说明了将能带理论应用于工程实际装备外壳的振动控制具有可行性。

Periodic design of equipment shell structure and its vibration property

The band gap (BG) theory of phononic crystals (PCs) is introduced into the structure design for equipment shell, and the cylindrical shell section of equipments is designed to be periodic composite material structure. Utilizing the model synthetical technology, the transmission characteristics of flexural vibration in the periodic and the non-periodic cylindrical shells are calculated and compared. Results show that, in the periodic shell structure, there are several flexural vibration BGs existed; whereas in the non-periodic shell, these BGs will disappear. Further, a periodic cylindrical shell made of composite laminated material is constructed and its vibration properties of are investigated. As expected, the existence of BGs in such a periodic structure is guaranteed and flexural vibration transmitting in this system will be attenuated apparently. Finally, as for practical engineering application, vibration properties of a complex equipment shell of which has periodic section in it are studied. Calculational results reveal that the introduction of BG theory into the vibration control for engineered equipment shell is quite feasible, since the complex equipment shell with locally periodic structure always maintain the BG characteristics.