Dynamic Analysis For Deployment Process Of Scissor Deployable Truss Structures

Deployable truss is a structure widely used in the areas of aerospace, machinery and constructionand its dynamical characteristics are important factors in the system design. For example, thedeployable truss structures are employed to design the deployable/retractable mast, the deployablespace antenna, the solar concentrator and so on. Along with fast development and application of thedeployable truss structures in the aerospace domain, investigations on deployable truss structures haveattracted a great deal of attention of domestic and foreign researchers, promoting further studiesconsequently.Through the kinematic analysis on deployable truss structures, we can learn whether or not thesystem deploys in the pre-designed route successfully and the relationships of positions, velocities andaccelerations of various nodes in the process of deployment. Based on the dynamic analysis, we canobtain position, velocity, acceleration and dynamic response and so on under the condition of externalforces. The above two kinds of analysis provide the important foundations for the design and theoptimization of deployable truss structures.Firstly, basic theories on the dynamics of multibody systems are introduced in this paper. Thenon-independent Cartesian coordinates are used to describe the configuration of the deployable trussstructures in order to construct dynamical equation with Lagrange technique, thus avoiding the troubleof artificial selection of independent coordinates. Moreover, the deducing process of the Lagrangeequation is highly stylized and it is expedient for the computer auxiliary analysis.Secondly, taking Cartesian coordinates of both ends of the beam as the generalized coordinates,the energy function of trussing and the mass matrix of beam are presented in Chapter2. Thefundamental restrict conditions of the deployable truss structures are analyzed in Chapter3withwhich it is convenient to set up the systems constraint equations by selecting the correspondingconstraint.Finally, according to the Lagrange method the jacobian matrix of the constraint equation and theright item of the acceleration are acquired. The dynamics of the deployable truss structures modelinclude the dynamical equation with Lagrange multiplier and constraint equation of the acceleration.We finish the dynamic analysis on deployment process by computer emulation.