{"id":161,"date":"2016-09-17T10:48:28","date_gmt":"2016-09-17T09:48:28","guid":{"rendered":"https:\/\/www.staff.ncl.ac.uk\/narakorn.srinil\/?page_id=161"},"modified":"2016-09-27T13:30:52","modified_gmt":"2016-09-27T12:30:52","slug":"ice-induced-vibration-iiv","status":"publish","type":"page","link":"https:\/\/www.staff.ncl.ac.uk\/narakorn.srinil\/ice-induced-vibration-iiv\/","title":{"rendered":"IIV @ FlexNARA"},"content":{"rendered":"<p>Oil &amp; gas explorations have been expanding in <strong>Arctic<\/strong> waters. However, numerical models for predicting IIV of offshore structures are still lacking. <strong>FlexNARA<\/strong> aims to develop a mathematical <em>reduced-order model<\/em> for predicting IIV effects on offshore structures under geometric coupling nonlinearities and <strong>chaotic<\/strong> (<em>intermittent<\/em>) ice loading behaviors. A cylindrical structure (e.g. spar platform or wind turbine monopile) subject to a moving uniform ice sheet is analyzed using the modified Matlock model which, in the present study, is extended to account for a new empirical nonlinear stress-strain rate relationship determining the maximum compressive stress of the ice. The model is further developed through the incorporation of ice temperature, brine content, air volume, grain size, ice thickness and ice wedge angle effects on the ice compressive strength. These allow effects of multiple ice properties on the <em>ice-structure interaction<\/em> to be investigated. The failed ice sheet length at a point of failure is also varied with time.<\/p>\n<div id=\"attachment_198\" style=\"width: 594px\" class=\"wp-caption alignleft\"><a href=\"https:\/\/www.staff.ncl.ac.uk\/narakorn.srinil\/files\/2016\/09\/IIV.jpg\" target=\"_blank\"><img loading=\"lazy\" decoding=\"async\" aria-describedby=\"caption-attachment-198\" class=\"wp-image-198 size-large\" src=\"https:\/\/www.staff.ncl.ac.uk\/narakorn.srinil\/files\/2016\/09\/IIV-1024x586.jpg\" alt=\"IIV\" width=\"584\" height=\"334\" srcset=\"https:\/\/www.staff.ncl.ac.uk\/narakorn.srinil\/files\/2016\/09\/IIV-1024x586.jpg 1024w, https:\/\/www.staff.ncl.ac.uk\/narakorn.srinil\/files\/2016\/09\/IIV-300x172.jpg 300w, https:\/\/www.staff.ncl.ac.uk\/narakorn.srinil\/files\/2016\/09\/IIV-768x439.jpg 768w, https:\/\/www.staff.ncl.ac.uk\/narakorn.srinil\/files\/2016\/09\/IIV-500x286.jpg 500w, https:\/\/www.staff.ncl.ac.uk\/narakorn.srinil\/files\/2016\/09\/IIV.jpg 1147w\" sizes=\"auto, (max-width: 584px) 100vw, 584px\" \/><\/a><p id=\"caption-attachment-198\" class=\"wp-caption-text\">IIV model with a series of non-uniform breakable ice teeth (H. McQueen &amp; N. Srinil, J Offshore Mechanics &amp; Arctic Engineering 2016, 138, 011501)<\/p><\/div>\n<p>The model is validated against results from the literature and provides new insights into IIV responses including the <span style=\"text-decoration: underline\"><em>quasi-static, random-like chaotic and locked-in<\/em><\/span> (<strong>similar to VIV<\/strong>) motions, depending on the ice velocity. Our numerical Matlock-Duffing model shows a potential to be used in future IIV analysis of arctic cylindrical structures, particularly fixed offshore structures such as lighthouses and wind turbine monopiles.<\/p>\n","protected":false},"excerpt":{"rendered":"<p>Oil &amp; gas explorations have been expanding in Arctic waters. However, numerical models for predicting IIV of offshore structures are still lacking. FlexNARA aims to develop a mathematical reduced-order model for predicting IIV effects on offshore structures under geometric coupling &hellip; <a href=\"https:\/\/www.staff.ncl.ac.uk\/narakorn.srinil\/ice-induced-vibration-iiv\/\">Continue reading <span class=\"meta-nav\">&rarr;<\/span><\/a><\/p>\n","protected":false},"author":1154,"featured_media":0,"parent":0,"menu_order":0,"comment_status":"closed","ping_status":"closed","template":"","meta":{"footnotes":""},"class_list":["post-161","page","type-page","status-publish","hentry"],"_links":{"self":[{"href":"https:\/\/www.staff.ncl.ac.uk\/narakorn.srinil\/wp-json\/wp\/v2\/pages\/161","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.staff.ncl.ac.uk\/narakorn.srinil\/wp-json\/wp\/v2\/pages"}],"about":[{"href":"https:\/\/www.staff.ncl.ac.uk\/narakorn.srinil\/wp-json\/wp\/v2\/types\/page"}],"author":[{"embeddable":true,"href":"https:\/\/www.staff.ncl.ac.uk\/narakorn.srinil\/wp-json\/wp\/v2\/users\/1154"}],"replies":[{"embeddable":true,"href":"https:\/\/www.staff.ncl.ac.uk\/narakorn.srinil\/wp-json\/wp\/v2\/comments?post=161"}],"version-history":[{"count":7,"href":"https:\/\/www.staff.ncl.ac.uk\/narakorn.srinil\/wp-json\/wp\/v2\/pages\/161\/revisions"}],"predecessor-version":[{"id":270,"href":"https:\/\/www.staff.ncl.ac.uk\/narakorn.srinil\/wp-json\/wp\/v2\/pages\/161\/revisions\/270"}],"wp:attachment":[{"href":"https:\/\/www.staff.ncl.ac.uk\/narakorn.srinil\/wp-json\/wp\/v2\/media?parent=161"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}