Our results showed that conventional wiring is the most advantageous closing method when compared to the others.

The main purpose of this study is to develop a validated three-dimensional finite element model of sternum closure techniques. For this aim, the finite element method analysis results of three closure methods were compared with experimental test results. Also, three more closure techniques are simulated numerically to study the effect of the number of wires used in the manubrium and xiphoid regions. A three-dimensional model of polyurethane sternum foam was created based on computed tomography images. Six different closure techniques using steel wire, steel bands and ZipFix bands were modeled on the sternum and transferred into a three-dimensional finite element model. The sternum was modeled as an isotropic bilinear-elasto-plastic material, and nonlinear contact conditions were applied. The models were analyzed under lateral distraction loading, and load-displacement curves were obtained from displacements at the incision line. Allowable loads and stiffness values of the methods were evaluated from these curves. The results showed the importance of the including material as well as geometric nonlinearities in the simulations to obtain realistic results from the numerical analyses. Also, the analyses showed that closures that include steel or ZipFix bands are superior to conventional wiring, and addition of a single wire at the manubrium and xiphoid regions significantly improved the efficiency of the closure techniques.

Bu çalışmada çelik tel, çelik kablo, titanyum klips ve titanyum plak kullanılarak yapılan dört farklı sternum kapama yönteminin etkinliği deneysel olarak karşılaştırıldı. Ça lış ma pla nı: Yapay sternum modellerinin kullanıldığı deneylerde, modellerde yanal ayrılma, boyuna kesme ve enine kesme oluşturacak şekilde statik yüklemeler yapıldı. Yöntemler emniyet yükü (2 mm deplasmana karşılık gelen yük) ve direngenlik değerleri dikkate alınarak karşılaştırıldı. Yöntemlerin maliyetleri, uygulama kolaylıkları ve hızları da değerlendirildi. Bul gu lar: Yanal ayrılmada en yüksek emniyet yükü ve direngenlik değerleri titanyum klips yönteminde elde edilmesine rağmen, tüm yöntemlerin emniyet yükleri ve direngenlikleri arasındaki farklılıklar istatistiksel olarak anlamlı değildi. Boyuna kesmede, en yüksek emniyet yükü titanyum plak yönteminde elde edilmesine rağmen, emniyet yüklerinde istatistiksel anlamlılık sadece çelik kablo yöntemi ve diğer yöntemler arasında vardı. Bu yüklemede en yüksek direngenlik değeri titanyum klips yönteminde elde edilirken bu yöntemle geleneksel tel yöntemleri arasındaki farklılık istatistiksel olarak anlamlı değildi. Enine kesmede en yüksek emniyet yükü ve direngenlik değerleri titanyum klips yönteminde elde edildi ve bu yöntemle diğer yöntemler arasındaki farklılıklar istatistiksel olarak anlamlı idi. Yöntemlerin maliyetleri, uygulama kolaylıkları ve hızları dikkate alındığında, en avantajlı yöntem geleneksel çelik tel yöntemi idi. So nuç:Deney sonuçlarımıza göre titanyum klipsler diğer yöntemlere kıyasla daha istikrarlı davranış sergiledi ve daha iyi sternal kapama sağladı.

Using a finite element strategy, this study investigates the behavior of beam-to-column connections in storage rack systems exposed to high temperatures. The purpose of this research was to develop moment−rotation (M−θ) curves after painting various structural members with varied configurations in order to evaluate the performance of intumescentcoated beams, uprights, and connectors, which are components of storage rack systems. Within the scope of this work, finite element analyses were carried out in two stages. First, thermal analyses were performed using the transient thermal analysis system of ANSYS Workbench software to estimate the ultimate temperatures of the beam, upright, and connector, which were painted with 1 mm thick paint and exposed to standard (ISO-834) fire. The results were then compared to the Eurocode 3 Part 1.2 with a satisfactory agreement. In the second stage of the analysis, a total of 9 possible alternative models were investigated in the static structural analysis system, reflecting the effect of applying fire protection to the different portions of the rack system. Since the most critical stress level is achieved around the connector tabs, it has been observed that protection of the connector in individual or binary conditions provides higher performance while protection of the beam causes divergent joint behavior. Additionally, comparison of fully protected and unprotected conditions presents an increment of more than 7% on the joint's ultimate moment capacity and initial stiffness, which is an explicit contribution of the intumescent coating to fire resistance.

No abstract