Investigation of strut collision in tensegrity statics and dynamics

Strut collisions can occur in tensegrity structures and seriously change the general mechanical behaviors of the structures. For many years, there have been few investigations into this topic. This paper systematically addresses the issue of strut collision modeling in tensegrity mechanical analyses. A general and efficient rigid body model for strut collision analysis is presented. A two-strut collision model is formulated using contact force methods. The normal contact force and the tangential friction force are evaluated by using the Lankarani–Nikravesh model and the modified Coulomb's friction law, respectively. Exact formulations of the generalized force vectors and the related tangent stiffness and tangent damping matrices are analytically derived. Fundamental issues related to collision detection and stiffness coefficient determination, are also addressed. Two representative examples involving both classical and clustered tensegrity structures are presented to demonstrate the effectiveness of the general framework, as well as to make a detailed study into the influence of collisions effects. Outcomes presented in this work will broaden the research discipline on tensegrity systems.