Question about wire model with beam element in ABAQUS

I want to do a finite element analysis of the braid vessel stent model with the B31 beam element and the explicit solver, and I find that the wires in the analysis are discontinuous. Should I add some constraints or cross-sectional connections?

I set the radial displacement of all the nodes, as usual the stent should be extended, but the result was not, and the lines became independent segments.

I used 3D  drawings in SOLIDWORKS to draw the model wire and save it as .igs file. Then I imported the wire into ABAQUS, and material is Nitinol.

Any help I would like to express my appreciation