Yazar "Kaya, Ercan Serif" seçeneğine göre listele

Listeleniyor 1 - 6 / 6
  • [ X ]
    Öğe
    A numerical study on the effect of vent/wall area ratio on Trombe wall thermal performance
    (Emerald Group Publishing Ltd, 2021) Kaya, Ercan Serif; Aksel, Murat; Yigit, Sadik; Acikara, Turgut
    Trombe walls are the most widely applied passive systems that utilise solar energy for heating massive walls. Although studies have been undertaken in the fields of Trombe wall application and design, the research on the effect of the vent area and the number of vents on the performance of a Trombe wall remains limited. In this context, a parametric study investigating the effect of the vent-to-wall-area ratio on Trombe wall performance was conducted. A computational fluid dynamics model was employed for validation analysis. The results were verified by experimental measurements of temperature. At each step of the parametric study, the vent-to-wall-area ratio in the Trombe wall model was increased by 2% starting from the unvented case, and the results were simulated per ratio. In this study, temperature measurements of the glazing, thermal wall and space were employed as the evaluation criteria. The results of the parametric runs showed that a Trombe wall with eight separate air vents and an 8% vent-to-wall-area ratio provides the maximum heating performance. Furthermore, a monolithic vent configuration with an 18% vent-to-wall-area ratio performed slightly better compared with other configurations of monolithic air vents.
  • Küçük Resim
    Öğe
    Determination of performance criteria of steel pipes subjected to axial compressive load and bending moment
    (Gazi Univ, Fac Engineering Architecture, 2023) Kaya, Ercan Serif
    Purpose:It is of great importance to understand the progression of post-buckling damage mechanism of steel pipes when subjected to axial compressive and bending loads. In this study, it is mainly aimed to predict the plastic deformation level and principal limit states for given steel pipes with specific D/t ratio and mechanical properties under combined loads.Theory and Methods:Three different types of pipe profile are chosen that correspond to the characteristics of water transmission, gas and oil pipelines in Turkey. These high strength steel pipe profiles are modeled by using finite element program and subjected to axial compressive loads followed by bending loads. Capacity demand curves of these pipes are obtained numerically after conducting validation studies in accordance with a previous experimental research work.Results:The limit state of high strength steel pipes due to axial load and bending conditions is associated with local buckling which mainly depends on mechanical and geometrical parameters of pipe, initial imperfection and internal pressure. Thames water pipe (with 122 of D/t ratio) has reached its 90% of failure mode when subjected to 4.48 degrees of rotation angle. As for TANAP natural gas pipe (D/t ratio is 50) and BTC oil pipe (D/t ratio is 46), limit state has been reached after 18.77 degrees and 26.64 degrees rotation angles, respectively.Conclusion:It is seen that there is an inverse relationship in between axial loading and bending capacities of steel pipes. The limit state values for high strength steel pipes are reached at lower rotation angles due to high D/t ratio. Axial compressive loads give rise to premature failures and promote plastic deformations even under small displacement values. These premature failures form plastic hinge points which are considered to be the beginning of buckling and cause advanced type of buckling damage mechanisms in the following steps.
  • [ X ]
    Öğe
    Earthquake damage mitigation methods for buried pipelines under compressive loads: A case study of the Thames water pipeline
    (Elsevier Sci Ltd, 2024) Kaya, Ercan Serif
    Promoting tensile failure by providing a proper orientation angle between the pipe axis and the fault line is the main seismic design philosophy for buried steel pipelines. However, most of the severe damage and failures experienced by pipelines are mainly due to negative crossing angle and thus compressive loads acting along the pipeline. This paper investigates different earthquake damage mitigation methods such as Carbon Fiber Reinforced Polymer (CFRP) wrapped pipes, Steel Pipes for Fault Crossing (SPF), and corrugated pipes for buried steel pipelines which are mainly subjected to compressive loads. Therefore, the Thames water transmission pipeline, which is a well-known case study, that suffered major and minor damage due to compressive forces in the 1999 Kocaeli earthquake, is considered to simulate and compare the earthquake damage mitigation capabilities of these countermeasures. The numerical studies are performed by using a three-dimensional nonlinear finite element model. The results show that the use of CFRP composites in buried pipelines, regardless of their thickness, wrapping length, or layer orientation, does not have the expected damage reduction effect, but does increase the effective length between major wrinkles or change the type of pipe failure. On the other hand, SPFs and corrugated pipes are more effective in earthquake damage reduction due to their high axial and rotational capabilities.
  • Küçük Resim
    Öğe
    Eksenel basınç kuvveti ve eğilme momentine maruz çelik boruların performans kriterlerinin saptanması
    (2023) Kaya, Ercan Serif
    Gömülü boru hatları su, doğalgaz ve petrol gibi hayati öneme sahip ürünlerin taşınması ve dağıtılması amacıyla kullanılan kritik alt yapı elemanlarıdır. Bu tür enerji nakil sistemleri, güzergahları üzerinde fay hatları ile kesişebilmekte, kesişim açısına bağlı olarak kalıcı zemin deformasyonları etkisinde çekme ve basınç gerilmelerine maruz kalabilmekte ve ciddi hasarlar alabilmektedirler. Tasarım ilkesi açısından çelik borularının çekme göçmesine maruz kalması beklenir. Fakat mecburi güzergâh sebebiyle ters ya da bazı yanal atımlı fayların kesilmesi gerektiği durumlarda net eksenel basınç kuvvetleri altında prematüre göçmeler yaşanabilmektedir. Mevcut yönetmeliğe göre, deprem etkisi altında kalan boru hatları için belirtilen tasarım esasları, kesintisiz kullanım ve kontrollü hasar durumları için tarif edilmiş en büyük eksenel çekme ve basınç birim yer değiştirme değerlerine göre sınırlandırılmıştır. Ancak, boruların özellikle basınç altındaki burkulma sonrası ileri seviye performansları yeteri kadar bilinmemektedir. Bu çalışma kapsamında, özelikle borularda basınç kaybı ve hasar oluşumuna sebebiyet veren eksenel basınç ve eğilme momenti altındaki limit durumları incelenmiştir. Bu amaçla, Türkiye’de bulunan mevcut boru hatlarını karakterize edecek şekilde, su isale (Kullar), doğalgaz (TANAP) ve petrol (BTC) boru hatlarına ait D/t oranları ile malzeme karakteristik özellikleri dikkate alınarak üç boyutlu sonlu elemanlar modeli yardımıyla birleşik yükleme koşulları altındaki davranışları incelenmiştir. Böylelikle, ötelenme miktarlarına ve rotasyon miktarlarına bağlı olarak borularda oluşacak limit durumlar belirlenmiştir. Söz konusu çalışma sonuçlarının ülkemizdeki boru hatlarının performans tabanlı tasarımlarında kullanılması beklenmektedir.
  • Küçük Resim
    Öğe
    Mechanical behavior of large-diameter pipe elbows under low-cyclic loading
    (2023) Kaya, Ercan Serif
    Large-diameter steel pipes are often used for transmitting and distributing water, gas, and oil products from the source to the end user. These pipelines are mainly oriented by using pipe el- bows due to their high flexibility along their routes. It is important to understand the mechani- cal behavior of these critical infrastructure components to promote material sustainability. For this purpose, a rigorous 3D finite element model is employed to investigate the mechanical behavior of large-diameter pipe elbows with varying elbow angles such as 90°, 60°, and 30°. Moreover, geometrical and material nonlinearities capture the pipes’ ratcheting behavior even under pressurized and unpressurized scenarios. It is seen that the pipes with a larger elbow angle can endure a higher number of cycles before they reach their limit states. In addition, pipe elbows behave similarly to straight pipes as the elbow angle decreases and becomes more vulnerable to plastic deformations such as kink and buckling under bending loads.
  • Küçük Resim
    Öğe
    Unidirectional CFRP Reinforcement in Buried Pipelines: Performance Limits at Strike-Slip Fault Crossings
    (Wiley, 2025) Kaya, Ercan Serif; Acar, Volkan; Cakir, Ferit; Taciroglu, Ertugrul
    The mechanical behavior and seismic performance of buried pipelines have been extensively investigated in recent years. However, to the best of the author's knowledge, research studies on the performance limits of these pipelines, particularly wrapped with unidirectional carbon fiber-reinforced polymer (CFRP) remain limited. This study examines the performance limits of buried steel pipelines reinforced with unidirectional CFRP as they cross strike-slip fault lines. The investigation focuses on the influence of fault angles and evaluates the effectiveness of CFRP reinforcement under these conditions. CFRP material properties were experimentally characterized by standardized tensile and three-point bending tests. A three-dimensional finite element model was developed using ABAQUS to simulate soil-pipe interaction across fault crossing scenarios with angles ranging from 0 degrees to 40 degrees. The study also considers various CFRP configurations, including single-layer (t = 1.5 mm) and four-layer (t = 6.0 mm) wrappings, with fiber orientations of 0 degrees and 90 degrees. Damage mechanisms such as local buckling, ovalization, and composite rupture were analyzed to assess performance limits under different fault angles. The results demonstrate that even a single layer of CFRP wrapping significantly enhances the displacement capacity of the pipeline compared to conventional steel pipelines. Reinforced configurations showed reduced stress concentrations and more ductile behavior under both tensile and compressive loading. These findings offer valuable insights into optimizing CFRP retrofitting strategies and enhancing the resilience and safety of buried pipeline infrastructure in seismically active regions.