{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,7,17]],"date-time":"2026-07-17T12:04:59Z","timestamp":1784289899715,"version":"3.55.0"},"reference-count":24,"publisher":"MDPI AG","issue":"7","license":[{"start":{"date-parts":[[2026,3,31]],"date-time":"2026-03-31T00:00:00Z","timestamp":1774915200000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Materials"],"abstract":"<jats:p>This study investigates the influence of out-of-plane beam skew on the cyclic performance of column-tree steel moment connections. Utilizing validated finite element (FE) models against experimental data, the cyclic responses of various configurations were evaluated under the AISC cyclic loading protocol up to a story drift ratio of 0.05 rad. Skew angles of 0\u00b0, 10\u00b0, 20\u00b0, and 30\u00b0 were examined across three representative beam depths. The results demonstrate that all configurations satisfy the AISC 341 acceptance criteria for Special Moment Frames (SMFs), maintaining at least 80% of the plastic moment capacity (0.8 Mp) up to a 0.04 rad story drift ratio. However, the introduction of beam skew resulted in a gradual reduction in energy dissipation capacity, with the total dissipated energy decreasing by 2.9\u20138.9% at a 30\u00b0 skew. Notably, the inelastic energy component was more sensitive to the skew than the frictional components, exhibiting a maximum reduction of 15.4%. While out-of-plane skew disrupted the symmetry of stress triaxiality and plastic strain at the beam-to-column interface, the overall fracture susceptibility was not significantly exacerbated up to 30\u00b0. Furthermore, column twisting remained within a negligible range (below 0.5\u00b0), and its impact on global stability was limited. Despite the general stability, a premature bolted splice failure was observed in deep beam configurations at a 30\u00b0 skew during the 0.05 rad drift cycles. Based on these findings, it is concluded that column-tree connections with an out-of-plane skew up to 30\u00b0 are viable; however, a design limit of 20\u00b0 is recommended for deep beam configurations to ensure structural integrity under extreme cyclic demands.<\/jats:p>","DOI":"10.3390\/ma19071401","type":"journal-article","created":{"date-parts":[[2026,3,31]],"date-time":"2026-03-31T16:34:08Z","timestamp":1774974848000},"page":"1401","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":1,"title":["Out-of-Plane Skew Effects on the Cyclic Performance of Column-Tree Steel Moment Connections"],"prefix":"10.3390","volume":"19","author":[{"given":"Geon-Woo","family":"Kim","sequence":"first","affiliation":[{"name":"MS Construction Technology Co., Ltd., 77 Yongbong-ro, Gwangju 61186, Republic of Korea"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-5738-5250","authenticated-orcid":false,"given":"Jong-Kook","family":"Hong","sequence":"additional","affiliation":[{"name":"School of Architecture, Sunchon National University, 255 Jungang-ro, Suncheon 57922, Republic of Korea"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2026,3,31]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"105630","DOI":"10.1016\/j.autcon.2024.105630","article-title":"Constructability-Based Design Approach for Steel Structures: From Truss Beams to Real-World Inspired Industrial Buildings","volume":"166","author":"Cucuzza","year":"2024","journal-title":"Autom. 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