•The beam-upright connections of racks play a relevant role in their seismic capacity.•This work supplements a previously-conducted testing campaign on such connections.•In those tests, different weld paths were compared, looking for ductile break modes.•In this paper, numerical simulations are performed in order to deepen the tests observations.•The influence of the weld paths on the connection stiffness, stress elastic distribution, and yielding onset is studied. This paper presents numerical simulations of a suite of cantilever seismic tests of speed-lock connections between beam and upright members of adjustable pallet rack systems. The tested specimens differ in the endplate-to-beam weld beads geometric configuration; the experimental results show that each weld configuration leads to different behavior, significantly affecting the connection capacity and ductility. As a result, the performed numerical simulations aim to better understand and deepen these observations. Special attention is paid to the initial (elastic) behavior of the tested assembly, albeit the stress redistribution after the first yielding has also been studied and found to be relevant. The numerical results are satisfactory compared with the experimental ones, and specific remarks are derived. This work is a part of a broader research effort aimed to improve the dissipative seismic behavior of racks; such research activity involves also upright-base plate connections testing, advanced numerical simulation, and proposal of rack ductility behavior factors.