This study investigates SMA 400 AW steel T-shaped welded steel plates (i.e. T-stub joints) through a combined experimental and numerical approach. It focused on thick plates to understand how weld properties and residual stress influence the overall load-displacement behaviour. Two T-shaped welded specimens were fabricated using intermittent fillet welds and subjected to three-point cyclic bending loading tests until failure. Strain gauges and displacement transducers recorded data throughout the cyclic loading process to monitor the behaviour of the specimens. Further, mechanical property variation of welded parts were investigated through metallurgical analyses and hardness testing. Numerical models were developed using ABAQUS finite element software, simulating the experimental setup under cyclic loading conditions. Residual stresses were incorporated into the numerical model using an idealized stress pattern based on the contour method, enhancing the predictive accuracy of the numerical models. This study shows that reliable numerical models can be developed for predicting the performance of welded steel members under cyclic loading conditions.