{"682388":{"#nid":"682388","#data":{"type":"event","title":"PhD Defense by Candas Oner","body":[{"value":"\u003Cp\u003ESchool of Civil and Environmental Engineering\u003C\/p\u003E\u003Cp\u003EPh.D. Thesis Defense Announcement\u003C\/p\u003E\u003Cp\u003EMODELLING BASED DESIGN AND OPTIMIZATION OF SPIDER-WEB INSPIRED GEOGRIDS IN COMPOSITE GEOMATERIAL SYSTEMS\u003C\/p\u003E\u003Cp\u003EBy Candas Oner\u003C\/p\u003E\u003Cp\u003EAdvisor:\u003C\/p\u003E\u003Cp\u003EDr. J. David Frost\u003C\/p\u003E\u003Cp\u003ECommittee Members: Dr. Fernando Patino-Ramirez (CEE), Dr. Rodrigo Borela Valente (SCI), Dr. Michael E. Helms (ME), Dr. Mark H. Wayne (Tensar), Dr. Jason T. DeJong (CEE\/UC Davis)\u003C\/p\u003E\u003Cp\u003EDate and Time: May 28, 2025. 2:00pm\u003C\/p\u003E\u003Cp\u003ELocation: SEB 122\u003C\/p\u003E\u003Cp\u003EMicrosoft Teams Meeting ID: 273 217 231 733; Passcode: pe6Vd7Yj\u003C\/p\u003E\u003Cp\u003EComplete announcement, with abstract, is attached.\u003C\/p\u003E\u003Cp\u003E\u003Cstrong\u003EABSTRACT\u003C\/strong\u003E\u003Cbr\u003EGeogrid reinforcement is typically used to stabilize the soil, both by interlocking soil\u003Cbr\u003Eparticles and by providing lateral restraint. These planar geogrid structures are used\u003Cbr\u003Ein numerous different geotechnical engineering applications, such as pavements,\u003Cbr\u003Eretaining walls, foundations, and encapsulation of stone columns. Spider-Web\u003Cbr\u003EInspired Geogrids are a concept that attempts to enhance and optimize the design\u003Cbr\u003Eof polymeric geogrid structures for ground reinforcement.\u003Cbr\u003EIn 2019, researchers at Georgia Tech began exploring the opportunities for new\u003Cbr\u003Egeometric configurations of geogrids. Based on inspiration from spider webs, these\u003Cbr\u003Estudies identified, early on, the characteristics of spider webs that could be\u003Cbr\u003Ebeneficial to their performance, including different aperture sizes and continuous\u003Cbr\u003EGeorgia Institute of Technology\u003Cbr\u003ESchool of Civil and Environmental Engineering\u003Cbr\u003EAtlanta, Georgia 30332-0355 U.S.A.\u003Cbr\u003EPhone: 404.894.9044\u003Cbr\u003EA Unit of the University System of Georgia \u2022 An Equal Education and Employment Opportunity Institution\u003Cbr\u003Eradial elements, amongst others. The resulting geogrid structures are referred to by\u003Cbr\u003Ethe name SpiderAx throughout this study.\u003Cbr\u003EThe three main features of SpiderAx geogrids are a stiff\/condensed center region, a\u003Cbr\u003Elarge number of radial members, and the unique shapes created by the intersection\u003Cbr\u003Eof those radial members with concentric chords. This added complexity to the\u003Cbr\u003Egeogrid design from bio-inspiration comes with the question of how to integrate the\u003Cbr\u003Eresulting \u2018unit-cell\u2019 spider-web inspired structures into a larger structure. This study\u003Cbr\u003Euses structural optimization concepts to optimize and enable the integration of\u003Cbr\u003Ethose initial unit-cell structures. Different numerical methods are employed to test\u003Cbr\u003Ethe effectiveness of these optimized structures. To test its structural properties,\u003Cbr\u003Esuch as its behavior under compressive and shear loading, the Finite Element\u003Cbr\u003EMethod is used. A coupled approach between the Finite Difference Method and the\u003Cbr\u003EDiscrete Element Method is utilized to evaluate the stabilization effect of geogrids\u003Cbr\u003Eon natural aggregate systems under varying boundary conditions.\u003Cbr\u003EAccording to the results of the analyses performed with the Finite Element Method,\u003Cbr\u003Ethe total normalized strain energy stored in SpiderAx is less than for other geogrid\u003Cbr\u003Econfigurations, which is related to the stiffer geogrid behavior. This baseline case is\u003Cbr\u003Ethen elaborated with different parametric analyses, including different node and rib\u003Cbr\u003Edimensions, eccentric loading conditions for the plate load testing, and shearing\u003Cbr\u003Eorientation and the initial surcharge pressure for interface shear testing. In optimal\u003Cbr\u003Eforms, it is demonstrated that SpiderAx configurations can lead to both economic\u003Cbr\u003Eand mechanical advantages.\u003Cbr\u003ELater in the thesis, the engineering performance of the geogrid is investigated with\u003Cbr\u003Ethe reverse approach, meaning that the influence of the geogrid on the stabilization\u003Cbr\u003Eof the soil is analyzed. The influence of different parameters such as geogrid\u003Cbr\u003Estiffness, boundary conditions, loading plate diameter, geogrid thickness, clump\u003Cbr\u003Esize, and clump aspect ratio are studied. It is shown that while the increase in the\u003Cbr\u003Egeogrid thickness and geogrid stiffness lead to better performance in terms of\u003Cbr\u003Esurface rutting, increase in the loading plate diameter hinders the ability of the\u003Cbr\u003Egeogrid to stabilize the soil in the simulations. It is also illustrated that in order to\u003Cbr\u003Einvestigate the clump size and aspect ratio, a combined analysis with the geogrid\u003Cbr\u003Eaperture should be performed, because it is found that the compatibility between\u003Cbr\u003Ethose can influence the benefits of using geogrids.\u003C\/p\u003E","summary":"","format":"limited_html"}],"field_subtitle":"","field_summary":[{"value":"\u003Cp\u003EMODELLING BASED DESIGN AND OPTIMIZATION OF SPIDER-WEB INSPIRED\u003Cbr\u003EGEOGRIDS IN COMPOSITE GEOMATERIAL SYSTEMS\u003C\/p\u003E","format":"limited_html"}],"field_summary_sentence":[{"value":"MODELLING BASED DESIGN AND OPTIMIZATION OF SPIDER-WEB INSPIRED GEOGRIDS IN COMPOSITE GEOMATERIAL SYSTEMS"}],"uid":"27707","created_gmt":"2025-05-13 14:44:20","changed_gmt":"2025-05-13 14:44:53","author":"Tatianna Richardson","boilerplate_text":"","field_publication":"","field_article_url":"","field_event_time":{"event_time_start":"2025-05-28T14:00:00-04:00","event_time_end":"2025-05-28T16:00:00-04:00","event_time_end_last":"2025-05-28T16:00:00-04:00","gmt_time_start":"2025-05-28 18:00:00","gmt_time_end":"2025-05-28 20:00:00","gmt_time_end_last":"2025-05-28 20:00:00","rrule":null,"timezone":"America\/New_York"},"location":"SEB 122","extras":[],"groups":[{"id":"221981","name":"Graduate Studies"}],"categories":[],"keywords":[{"id":"100811","name":"Phd Defense"}],"core_research_areas":[],"news_room_topics":[],"event_categories":[{"id":"1788","name":"Other\/Miscellaneous"}],"invited_audience":[{"id":"78771","name":"Public"}],"affiliations":[],"classification":[],"areas_of_expertise":[],"news_and_recent_appearances":[],"phone":[],"contact":[],"email":[],"slides":[],"orientation":[],"userdata":""}}}