{"id":7806,"date":"2024-12-15T23:39:06","date_gmt":"2024-12-15T20:09:06","guid":{"rendered":"https:\/\/niazit-ceiling.com\/en\/?p=7806"},"modified":"2026-02-11T18:11:10","modified_gmt":"2026-02-11T14:41:10","slug":"truss-action-in-steel-joists","status":"publish","type":"post","link":"https:\/\/niazit-ceiling.com\/en\/truss-action-in-steel-joists\/","title":{"rendered":"Truss Action in Steel Joists"},"content":{"rendered":"\t\t
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\u2728 Truss Action in Steel Joists \u2728<\/h1>\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t\t<\/div>\n\t\t<\/div>\n\t\t\t\t\t<\/div>\n\t\t<\/section>\n\t\t\t\t
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Introduction<\/h2>

The concept of truss systems<\/strong> is widely used not only in bridges and building structures, but also in steel joist floor systems<\/strong>. This article examines the structural behavior of truss action in steel joists<\/strong>, comparing open-web joists (Kormit type)<\/strong> with joists without concrete infill in the web (NIAZIT system)<\/strong>.<\/p>

What Is a Truss?<\/h2>

A truss is a structural system composed of straight members connected to form triangular units<\/strong>. Each member is designed to resist axial tension or compression only<\/strong>. In ideal truss behavior:<\/p>

  • Members are free of bending moments and shear forces<\/p><\/li>

  • Connections are modeled as pinned joints<\/strong><\/p><\/li>

  • The overall system behaves as a flexural load-carrying structure<\/strong><\/p><\/li><\/ul>

    Truss Behavior in Open-Web (Kormit) Joists<\/h2>

    In open-web joists, the web member is formed as a continuous zigzag element<\/strong>. This configuration:<\/p>

    • Does not form perfect triangular units<\/p><\/li>

    • Experiences alternating tension and compression<\/strong> within a single continuous member<\/p><\/li>

    • Results in combined axial stresses in curved regions<\/p><\/li><\/ul>

      Therefore, defining this system as a true truss is structurally ambiguous<\/strong>. Concrete infill in the web helps restrain deformation of the zigzag member; however, its effectiveness depends heavily on proper concrete quality, vibration, and curing.<\/p>

      Under dynamic loads such as seismic actions<\/strong>, poor concrete performance may lead to progressive long-term deflection<\/strong>, as each curved segment is simultaneously subjected to tension and compression.<\/p>\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t\t<\/div>\n\t\t<\/div>\n\t\t\t\t\t<\/div>\n\t\t<\/section>\n\t\t\t\t

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      \ud83d\udd34 Compression zone<\/p>

      \ud83d\udd35 Tension zone<\/p>\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t\t<\/div>\n\t\t<\/div>\n\t\t\t\t

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      Simultaneous tension and compression in continuous curved web members<\/p>\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t\t<\/div>\n\t\t<\/div>\n\t\t\t\t

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      Continuous zigzag web reinforcement (Kormit joist)<\/p>\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t\t<\/div>\n\t\t<\/div>\n\t\t\t\t\t<\/div>\n\t\t<\/section>\n\t\t\t\t

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      Truss Behavior in Joists Without Concrete Web (NIAZIT)<\/h2>

      In NIAZIT joists, the web consists of independent vertical and diagonal members<\/strong>:<\/p>

      • Vertical members resist compression<\/strong><\/p><\/li>

      • Diagonal members resist tension<\/strong><\/p><\/li><\/ul>

        This configuration creates true triangular truss geometry<\/strong>, where:<\/p>

        • Each member carries a single axial force<\/p><\/li>

        • Members are individually welded<\/p><\/li>

        • Joint behavior closely resembles pinned connections<\/p><\/li><\/ul>

          As a result, the truss action in NIAZIT joists is more efficient, predictable, and independent of concrete infill<\/strong>.<\/p>\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t\t<\/div>\n\t\t<\/div>\n\t\t\t\t\t<\/div>\n\t\t<\/section>\n\t\t\t\t

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          \ud83d\udd34 Compression zone<\/p>

          \ud83d\udd35 Tension zone<\/p>\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t\t<\/div>\n\t\t<\/div>\n\t\t\t\t

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          Independent tension and compression resistance in each member<\/p>\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t\t<\/div>\n\t\t<\/div>\n\t\t\t\t

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          Independent tension and compression resistance in each member<\/p>\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t\t<\/div>\n\t\t<\/div>\n\t\t\t\t\t<\/div>\n\t\t<\/section>\n\t\t\t\t<\/div>\n\t\t","protected":false},"excerpt":{"rendered":"

          \u2728 Truss Action in Steel Joists \u2728 Introduction The concept of truss systems is widely used not only in bridges and building structures, but also in [\u2026]<\/span><\/p>\n","protected":false},"author":1,"featured_media":3130,"comment_status":"open","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[33],"tags":[],"class_list":["post-7806","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-uncategorized"],"_links":{"self":[{"href":"https:\/\/niazit-ceiling.com\/en\/wp-json\/wp\/v2\/posts\/7806","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/niazit-ceiling.com\/en\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/niazit-ceiling.com\/en\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/niazit-ceiling.com\/en\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/niazit-ceiling.com\/en\/wp-json\/wp\/v2\/comments?post=7806"}],"version-history":[{"count":0,"href":"https:\/\/niazit-ceiling.com\/en\/wp-json\/wp\/v2\/posts\/7806\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/niazit-ceiling.com\/en\/wp-json\/wp\/v2\/media\/3130"}],"wp:attachment":[{"href":"https:\/\/niazit-ceiling.com\/en\/wp-json\/wp\/v2\/media?parent=7806"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/niazit-ceiling.com\/en\/wp-json\/wp\/v2\/categories?post=7806"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/niazit-ceiling.com\/en\/wp-json\/wp\/v2\/tags?post=7806"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}