Hibrit kompozit çubuklarda burkulma analizi
Küçük Resim Yok
Tarih
2025
Yazarlar
Dergi Başlığı
Dergi ISSN
Cilt Başlığı
Yayıncı
İnönü Üniversitesi
Erişim Hakkı
info:eu-repo/semantics/openAccess
Özet
Bu çalışma, deprem etkileri altında burkulma riski yüksek kolonlarda epoksi esaslı fiber takviyeli polimer (FRP) kaplamaların taşıma kapasitesine etkisini sonlu elemanlar yöntemiyle incelemektedir. C30 beton çekirdek, dört adet S355 donatı ve altı tabakalı FRP kaplamadan oluşan kolonlar; 3 mm, 4 mm ve 5 mm donatı serilerinde modellenmiş, fiber yönelimi 0°–90° aralığında 15°'lik artışlarla değiştirilerek toplam 273 konfigürasyon analiz edilmiştir. Bu çalışma, FRP kaplamaların üç boyutlu kolon modelleriyle bütünleşik olarak incelenmesini sağlayan özgün bir modelleme stratejisi sunarak, literatürdeki klasik yüzey ve kabuk tabanlı uygulamaların ötesine geçmektedir. Kritik burkulma yükleri Static Structural–Eigenvalue Buckling çözümleriyle elde edilmiş ve tüm yüzdesel değişimler kompozit kaplamasız referans modellerle karşılaştırılmıştır. Ayrıca karbon, kevlar ve cam fiberli modeller üzerinde 2 mm deplasman kontrollü yükleme ile yapılan Force Reaction analizleri, FRP kaplamaların kolon rijitliği ve süneklik eğilimlerini belirgin biçimde değiştirdiğini göstermiştir. Sonuçlar, 0° fiber yöneliminde kapasite artışının 3 mm serisinde 3CCCCCC modeli için %172,2, 4 mm serisinde 4CCCCCC modeli için %160,7, 5 mm serisinde 5CCCCCC modeli için %145,8 seviyelerine ulaştığını göstermiştir. Tam karbon dizilimleri (CCCCCC) en yüksek dayanımı sağlarken, karbon ağırlıklı hibrit dizilimlerde (ör. ACACAC, CAGCAG, GCGCGC) %60–110 aralığında dengeli artışlar elde edilmiştir. Fiber açısı büyüdükçe kapasite azalmış ve 60°–75° aralığında karbon dizilimlerinde %5–7, hibritlerde %12–18, kevlar–cam tabanlı dizilimlerde %17–23 aralığında kayıplar ortaya çıkmıştır. Donatı çapının 3 mm'den 5 mm'ye çıkması ise genel rijitliği %8–12 artırmış ve maksimum kapasite 5CCCCCC modelinde 926,88 kN olarak elde edilmiştir. Sonuç olarak, karbon oranı yüksek ve fiber yönelimi 0°–30° aralığında olan FRP kaplamalar burkulma dayanımını en fazla artıran konfigürasyonlar olarak belirlenmiş; hibrit FRP sistemlerin deprem bölgelerinde kolon rijitliğini ve sünekliğini artırarak burkulma kaynaklı göçme riskini azaltan etkili bir güçlendirme yöntemi sunduğu gösterilmiştir.
This study investigates the effect of epoxy-based fiber-reinforced polymer (FRP) jackets on the load-carrying capacity of columns with high buckling risk under seismic conditions using the finite element method. Column models consisting of a C30 concrete core, four S355 steel rebars, and a six-layer FRP jacket were generated in three reinforcement series with 3 mm, 4 mm, and 5 mm bar diameters. A total of 273 configurations were analyzed by varying the fiber orientation between 0° and 90° in 15° increments. This study introduces a novel modeling strategy that enables FRP jackets to be examined in an integrated manner with three-dimensional solid column models, thereby extending beyond the classical surface- and shell-based approaches in the literature. Critical buckling loads were obtained through Static Structural–Eigenvalue Buckling analyses, and all percentage variations were evaluated with respect to unjacketed reference models. Furthermore, Force Reaction analyses performed under a 2 mm displacement-controlled loading on carbon, kevlar, and glass-fiber models demonstrated that FRP jacketing significantly alters the axial stiffness and ductile–brittle tendencies of the columns. Results showed that at 0° fiber orientation, capacity enhancements reached 172.2% for the 3CCCCCC configuration, 160.7% for 4CCCCCC, and 145.8% for 5CCCCCC. Fully carbon configurations (CCCCCC) provided the highest capacity, while carbon-dominated hybrid layups such as ACACAC, CAGCAG, and GCGCGC achieved moderate increases between 60% and 110%. With increasing fiber angle, the capacity decreased, yielding losses of 5–7% in carbon configurations, 12–18% in hybrid ones, and 17–23% in kevlar–glass-based configurations within the 60°–75° range. Increasing the rebar diameter from 3 mm to 5 mm improved the overall stiffness by 8–12%, and the maximum load-carrying capacity was obtained as 926.88 kN in the 5CCCCCC model. Consequently, FRP jackets with high carbon content and fiber orientations between 0° and 30° were identified as the most effective configurations for enhancing buckling resistance, and hybrid FRP systems were shown to provide an efficient strengthening method by improving the stiffness and ductility of columns and reducing buckling-induced collapse risk in seismic regions.
This study investigates the effect of epoxy-based fiber-reinforced polymer (FRP) jackets on the load-carrying capacity of columns with high buckling risk under seismic conditions using the finite element method. Column models consisting of a C30 concrete core, four S355 steel rebars, and a six-layer FRP jacket were generated in three reinforcement series with 3 mm, 4 mm, and 5 mm bar diameters. A total of 273 configurations were analyzed by varying the fiber orientation between 0° and 90° in 15° increments. This study introduces a novel modeling strategy that enables FRP jackets to be examined in an integrated manner with three-dimensional solid column models, thereby extending beyond the classical surface- and shell-based approaches in the literature. Critical buckling loads were obtained through Static Structural–Eigenvalue Buckling analyses, and all percentage variations were evaluated with respect to unjacketed reference models. Furthermore, Force Reaction analyses performed under a 2 mm displacement-controlled loading on carbon, kevlar, and glass-fiber models demonstrated that FRP jacketing significantly alters the axial stiffness and ductile–brittle tendencies of the columns. Results showed that at 0° fiber orientation, capacity enhancements reached 172.2% for the 3CCCCCC configuration, 160.7% for 4CCCCCC, and 145.8% for 5CCCCCC. Fully carbon configurations (CCCCCC) provided the highest capacity, while carbon-dominated hybrid layups such as ACACAC, CAGCAG, and GCGCGC achieved moderate increases between 60% and 110%. With increasing fiber angle, the capacity decreased, yielding losses of 5–7% in carbon configurations, 12–18% in hybrid ones, and 17–23% in kevlar–glass-based configurations within the 60°–75° range. Increasing the rebar diameter from 3 mm to 5 mm improved the overall stiffness by 8–12%, and the maximum load-carrying capacity was obtained as 926.88 kN in the 5CCCCCC model. Consequently, FRP jackets with high carbon content and fiber orientations between 0° and 30° were identified as the most effective configurations for enhancing buckling resistance, and hybrid FRP systems were shown to provide an efficient strengthening method by improving the stiffness and ductility of columns and reducing buckling-induced collapse risk in seismic regions.
Açıklama
Anahtar Kelimeler
Makine Mühendisliği, Mechanical Engineering
