This study comparatively investigates the seismic performance parameter analysis of frame-shear wall dual systems incorporating special-shaped steel-concrete-filled steel tubular (SSS-CFST) composite columns through finite element simulation. A numerical model is established for an SSS-CFST composite column frame integrated with reinforced concrete shear walls under cyclic loading. Compared to a control frame system without shear walls, the dual system demonstrates significantly enhanced lateral load-bearing capacity, sharper stiffness degradation in the early loading stage, and improved energy dissipation efficiency initially, though a pinching effect is observed in its hysteresis response. Furthermore, the SSS-CFST frame-shear wall structure exhibits superior performance in load-bearing, stiffness, and energy dissipation compared to conventional CFST frame-shear wall systems, whether considered for new construction or retrofitting applications. An additional scaling analysis reveals systematic differences in quantitative performance metrics between scaled models and full-scale prototypes. Specifically, scaled models of these structures in numerical simulations may overestimate energy dissipation capacity and underestimate plastic-stage stiffness. The findings provide theoretical support for the seismic design and analysis of SSS-CFST composite column frame-shear wall structures in high-rise buildings.
Flat-corrugated plate steel shear walls (FCoPSSWs) form a hybrid lateral load-resisting system by combining corrugated and flat steel plates, enhancing performance over standard corrugated plate steel shear walls (CoPSSWs). This research uses ABAQUS to simulate the lateral response of three-layer FCoPSSWs and compares their behavior under monotonic and cyclic loads with CoPSSWs. It explores the effects of aspect ratio (b/h), corrugation orientation, and corrugation angle, with seven aspect ratios ranging from 0.5 to 2 and angles at 30°, 45°, and 60°. The model's validation against experimental data shows a maximum strength deviation of 1.2
Many cases of corrosion and fatigue damage have been reported in steel bridges in Japan. Patch-plate repair using high-strength bolts is commonly applied to steel members with partial corrosion damage or fatigue cracks. In patch-plate repair, the applied load is shared between the patch and main plates. Consequently, the load transfer mechanism is more complex than in joining. In this study, a simple estimation equation based on shear lag theory is proposed to evaluate load transfer in steel plates with cross-sectional loss and fatigue cracks that are repaired using patch plates with high-strength bolts. The formulation explicitly accounts for both load-transferring and non-load-transferring regions. In addition, finite element analyses were conducted for patch-repaired steel plates with cross-sectional loss and fatigue cracks to validate the proposed method. The estimated axial forces generally agree with the FE results within ± 10
Reliable screening of concrete-filled steel tubular (CFST) axial capacity requires residual estimates that remain informative beyond the experimental sources represented in training. Random K-fold validation can split specimens from one publication across folds and understate this source-generalization uncertainty. We reconstructed a frozen dataset of 2715 axial tests from 166 publication/test-program groups in two parent databases and compared two mechanics baselines with six machine-learning families under random K-fold, reference-group K-fold, and parent-database leave-one-source-out (LOSO) validation. For histogram gradient boosting, the standard deviation of the log prediction ratio increased from 0.105 under random K-fold to 0.199 under reference-group K-fold and 0.195 under parent-database LOSO. The empirical prediction reduction factor for a 5
In this research, we investigated the impact of a notch on the fatigue response of butt-welded joints fabricated from Q460qD steel and CHE557RH welding rods through experiment. The fatigue crack initiation life, stable crack propagation period, and total life under cyclic loading of the notched butt-welded joints under varying nominal maximum stresses and stress amplitudes were carefully measured. Theoretical and numerical analyses of fatigue cracking in the notched butt-welded joints were subsequently performed using an ellipsoidal fracture model as the criterion for both fatigue crack instability propagation and crack tip initiation. The fatigue crack initiation life, stable crack propagation period, and total life of the notched butt-welded joints were predicted using a unified fatigue model that integrates the fatigue crack initiation and stable crack propagation periods. Overall, the unified fatigue model predicted crack-initiation life, stable crack-propagation period, and total fatigue life with errors confined to a modest margin of error under all loading conditions.
