Abstract: A novel method to prepare equipment section support for flight vehicle is proposed by using lightweight thermoplastic composites prepared by selective laser sintering (SLS), in order to meet the requirements of lightweight, rapid development and structure optimization in equipment section support. Considering the special service environment of equipment section support, the process parameter optimization for preparing the short carbon fiber reinforced PA12 composites by SLS is carried out and the mechanical property, thermal behavior and dynamic mechanical property of the carbon fiber reinforced nylon12 composites prepared by SLS are studied, and the test results show that the tensile strength is about 63.8 MPa with an elastic modulus of 6.5 GPa, the flexural strength reached to 118.06 MPa and the damping factor is 0.03-0.06, which is much higher than metal material, indicating a better damping performance. The fracture morphology of composites shows massive pores and its bulk density is only about 1.03 g/cm³, which is far lower than metal material. Meanwhile, several assemble methods are used for the composites prepared by SLS, and the pulling-out force and failure behavior are assessed. At last, an equipment section support in rocket and the optimized structural support are prepared by SLS, and the weight of the optimized structural support is only 60% of the original. The results of load experiment shows these two supports both can withstand the load of 2 000 N without destruction and clear deformation, which demonstrated the feasibility and the potentials in the aerospace field of proposed method, as the technical advantage of SLS in the lightweight, rapid development and structure optimization.

Key words: additive manufacturing, carbon fiber reinforced nylon12, equipment section support, selective laser sintering, topology optimization