Stainless steel pipe fittings are the main heavy load bearing components on the support. The structural design and optimization of stainless steel pipe fittings, the preparation technology of stainless steel pipe fittings, the theoretical design and experimental analysis of axial compression properties were studied. Strength design has always been a difficult and hot point in the structural design of stainless steel pipe fittings, and is the most important link. Whether it is angle ply stainless steel pipe fittings or axial/circumferential orthogonal ply pipe fittings, the axial compressive strength of pipe fittings can be significantly improved with an appropriate amount of circumferential ply. After changing the angle ply (axial ply) of 20% to circular ply, the axial compressive strength of stainless steel pipe fittings with winding angle of 20 ° has been increased by about one time, and the axial compressive strength of stainless steel pipe fittings with orthogonal ply has also been increased by more than 10%.

Through the finite element model analysis of the bearing capacity of the composite thrust support on the X-33 and Atlas V launch vehicles, which are used to validate the reusable launch vehicle, it is pointed out that the X-33 thrust support has a good comprehensive bearing capacity and is suitable for more complex load conditions, while the Atlas V thrust support has a good compression bearing capacity and is suitable for the load conditions with large thrust.

The problem of mechanical strength continues to be a difficulty for all stainless steel pipe fittings. Whether from the perspective of angle ply or axial/circumferential orthogonal ply, a reasonable amount of circumferential ply can significantly enhance the axial compressive mechanical strength of stainless steel pipe fittings.