Nonlinear Response of a Planar Repetitive Space Truss with Joints Based on Multi-Harmonic Equivalent Model
Xinyuan Li, Guo Wei, Jiaojiao Guo, Fushou Liu, Yuan Ji, Dongping Jin
Abstract: This paper presents a nonlinear response of a planar repetitive space truss with polynomial-nonlinear joints based on a multi-harmonic equivalent continuum beam model. The nonlinear joints are modeled as the multi-harmonic dynamic stiffness matrix with eccentricity. To overcome the limitation of classical equivalent method based on energy, a high-order displacement equivalent modeling method is proposed, where the micro-rotation is included to improve the accuracy and avoid the pseudo inverse of matrix. Furthermore, in the experiment, a novel suspension device used to support the space truss structure is designed, which not only offsets the gravity but allows the truss to bend and twist freely on the granite table. A bending sweeping test was conducted to obtain the nonlinear frequency response of bending and bending-torsion coupling of the space truss. The results show the similar nonlinear characteristic between the nonlinearity of joints and the repetitive truss. During the vibration test, the coupled torsional vibration of planar repetitive truss has a larger amplitude at the bending resonance frequencies, rather than at the torsion resonance frequencies, indicating a nonlinear bending-torsion coupling feature.
文章链接：https://link.springer.com/article/10.1007/s11012-023-01660-7
