锁定状态下一维可展桁架球铰连接刚度识别

Stiffness identification of the spherical hinge of locked 1D deployable truss

针对某一维可展桁架的球形铰链连接,利用动力学模型修正方法识别了其连接刚度特性。将可展结构进行简化处理,使其处于展开锁定状态,单独考虑铰链刚度。对锁定后的展开单元进行精细化有限元建模,利用接触分析方法,得到球铰连接等效线性刚度初值。建立展开单元的参数化模型,并采用六向刚度弹簧单元对球铰连接进行等效线性处理。对锁定状态下的可展开结构单元进行模态测试,利用试验模态参数识别球铰的连接刚度。将识别的连接刚度值带入由三个展开单元组成的一维可展桁架,通过与试验模态数据对比验证了识别结果的准确性。研究结果表明,利用该基于动力学模型修正的空间可展开结构球铰连接刚度识别方法,能够准确识别球铰连接刚度,建立准确的动力学分析模型。

For the spherical hinge’s connection of a 1D deployable truss,the stiffness of the spherical hinge was investigated based on dynamic model updating.The deployable structure was simplified to be in locked condition,considering the stiffness of the spherical hinge only.First,we established the elaborate FEM of a locked truss unit and calculated the initial stiffness values by carrying out the contact analysis.Then we substituted the initial value with the parameterized model with six-directional stiffness spring elements linearizing the spherical hinges’connection.Afterward,we carried out the modal tests for this locked truss unit,using these modal parameters to identify the spherical hinge’s stiffness.Finally,we utilized the identified stiffness for the finite element modeling of the deployable structure and verified the identified results by using the multi-layer’s modal parameters.The results show that the stiffness identification method of the spherical hinge based on dynamic model updating presented by this paper is effective.