Mechanical Analysis Of Composite Truss Structure

Since composite materials has the following characteristics, high specific strength, high specific stiffness, good fatigue resistance, good vibration damping etc., it has been developed to be one of the most important material systems—metal materials, inorganic nonmetallic materials and polymeric materials. Advanced composite materials can reduce the structure weight of vehicle effectively and increase the pay-load, it has become a main research field of new materials in astronautics field.The present paper investigates the mechanical properties of composite truss structure where the braided composite joint of carbon fiber and the filament-wound pipe are used. For the truss structure of composite materials, a finite element model is built and the corresponding static problem is analyzed. The stress and deformation distributions are numerically solved by taking into account the pipe`s winding angle, joint`s braided angle and structure height. Due to the special working environment of the truss structure of composite, it's necessary to carry out the modal analysis of the truss structure and determine the inherent frequency and modal vibratory-type. In order to avoid the resonance and any other failure, the harmonic analysis has been carried out. From numerical results, it can be found that the resonance occurs near the first inherent frequency. It's identical to the result of modal analysis. Then the similar contents with the static analysis is considered and the displacement, velocity and acceleration components at some given points of truss structure are calculated by taking into account the pipe`s winding angle, structure height and constant damping ratio. Harmonic analysis describes the frequency response of composite truss structure and mode analysis offers a reference to avoid the system resonance. These results obtained by this paper provide an important reference for the truss structure design of composite materials.