梁式全碳纤维复合材料桁架模态及阻尼特性

为表征梁式全碳纤维复合材料桁架模态及阻尼特性,建立实体单元有限元模型进行桁架模态仿真,提出基于仿真结果采用模态应变能阻尼模型计算结构阻尼损耗因子的方法;此外,为提高模态分析效率,引入梁等效理论建立等效分析方法.仿真及等效分析结果与实测值的对比表明:梁等效理论、仿真及实验所得振型基本一致;仿真频率及结构阻尼损耗因子计算值误差均小于10%,所述模态仿真和阻尼计算方法有效,最后基于仿真结果验证了梁等效理论针对大尺度桁架模态的分析精度.

Modes and damping characteristics of beam-like all carbon fiber composite truss

In order to obtain modes and damping characteristics of beam-like carbon fiber composite truss, a solid finite element model is established for truss modes simulation. It is then proposed to compute the structural damping loss factors based on the simulated results, using modal strain energy damping model. To improve the effciency of modes analyzation, also, an equivalent analysis approach for truss modes is presented, which is based on beam equivalence theory. Comparisons are made among the simulated results,equivalent analysis results and actual measurement, respectively, which show that vibration shapes from equivalent analysis, simulation and the experiment agree well. In addition, errors of the simulated natural frequencies and the calculated structural damping loss factors are both less than 10%. These validate the applicability of both the presented modes simulation method and damping computation method. Finally, the equivalent analysis approach is demonstrated to be rather efficient for modes of large scale truss, based on the simulation results.