Residual mechanical properties of high strength steel bolts subjected to heating-cooling cycle

Kodur, Venkatesh; Yahyai, Mahmood; Rezaeian, Abbas; Eslami, Mohamadreza; Poormohamadi, Alireza

doi:10.1016/j.jcsr.2017.01.007

Cited by 50 publications

(21 citation statements)

References 19 publications

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“…The temperatures of the joint bolts' mid-points were below 220 • C throughout the fire testing. Consequently, the residual mechanical properties of the joint bolts were very similar after cooling [26]. Moreover, regardless of whether the fire lasted 60 or 120 min, the compression regions of the segments experienced only room temperature because they were so far from the heated surface.…”

Section: Load Test Results and Discussionmentioning

confidence: 95%

Thermal Behavior of Tunnel Segment Joints Exposed to Fire and Strengthening of Fire-damaged Joints with Concrete-filled Steel Tubes

Luo

Zang

2019

Applied Sciences

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Owing to its discontinuous configuration, segment joint is of particular concern when the shield tunnel lining is exposed to fire. The thermal behavior of such joints when exposed to fire was investigated experimentally in full scale. In addition, the effectiveness of using concrete-filled steel tubes (CFSTs) to restore joint strength after a fire was also investigated. Five full-scale reinforced concrete segment joints were fabricated. Four were exposed to the ISO 834 standard fire for 60 or 120 min, with the fifth serving as a control. Two fire-damaged specimens were then strengthened with CFSTs. All five specimens were then loaded to failure at room temperature. It was found that: (1) The effect of the joint gap on the temperature distribution was observed to change markedly during heating; (2) the temperature of the bolt end was much higher than that of the bolt mid-point, insulating the bolt ends is probably called for; (3) the bearing capacity and flexural stiffness of the fire-damaged segment joints can be significantly improved by strengthening with CFSTs.

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Section: Load Test Results and Discussionmentioning

confidence: 95%

Thermal Behavior of Tunnel Segment Joints Exposed to Fire and Strengthening of Fire-damaged Joints with Concrete-filled Steel Tubes

Luo

Zang

2019

Applied Sciences

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“…300 °C ısıtma döngüsünün ötesinde, M6 bulonları artık nihai güçlerini hızla kaybederler. Bu nedenle, sıcaklığın M6 bulon ve 5.5/6.3*90 vidalarının artık mekanik özellikleri üzerindeki etkisi sırasıyla 300 °C ve 500 °C'ye kadar daha az belirgin olduklarından dolayı kritik sıcaklık (Kodur, 2017). Bununla birlikte, bulonlar yukarıda belirtilen tepe sıcaklıklarının ötesine ısıtıldığında, artık kuvvetleri benzer bir şekilde hızla düşer (Kodur ve Aziz, 2014…”

Section: şEkil 2 Yüksek Sıcaklıklı Kül Fırını Ve çIft Eksenli Hidrolunclassified

“…Bulonların ısıtma çevrimi 500 °C'nin altında olduğunda, bulonların elastisite modüllerinin çoğunu yeniden kazandığı görülebilir. 600 ° C'nin üzerine ısıtıldığında, her iki bulon grubu da elastisite modülünde önemli ölçüde değişimler görülmektedir (Kodur, 2017). 650 °C ısıtma-soğutma döngüsünden sonra elastisite modülün en az % 75'i geri kazanılır.…”

Section: Artık Akma Dayanımı Ve Elastisite Modülüunclassified

Çelik Yapılarda Kullanılan Birleşim Elemanlarının Yangın Etkisinin Deneysel Olarak İncelenmesi

Yazici

Koşatepe

2020

Iğdır Üniversitesi Fen Bilimleri Enstitüsü Dergisi

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ÖZET: Bu çalışmada, yüksek sıcaklıklara (600 °C, 800 °C ve 1000 °C) maruz kalmış bulon ve vidaların mekanik özellikleri araştırılmıştır. Gerilme şekil değiştirme, elastisite modülü, verim ve nihai dayanımlar gibi artık mekanik özellikler ve ayrıca bulonların göçme modları çeşitli hedef sıcaklıklara maruz kaldıktan sonra kontrol numuneleri ile karşılaştırmaları yapılmıştır. Sıcaklık seviyesi, ham madde çeliklerinin kimyasal kompozisyonu ve 12.9 dayanım sınıfı bulonların üretim sürecinde ısıl işlem özelliklerinin artık mekanik özellikler üzerine etkisi incelenmiştir. Testlerden elde edilen veriler, bulonların, 400 °C'nin üzerindeki sıcaklıklarda artık gerilmede hızlı bir azalma olduğunu ve 800 °C'ye maruz kaldıktan sonra nihai dayanımın % 48.6'sine ulaştığını gözlemlenmiştir. Birleşim araçların karbon miktarı ve bulon üretiminde temperleme sıcaklığı dışında, bulonların ve vidaların artık mekanik özelliklerini önemli ölçüde etkilediği görülmektedir.

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“…Until now, only a few recommendations have been published, see [4], [17]. The reduction factors for class 10.9 bolts in [4] are based on tension tests on bolt assemblies and milled specimens; shear tests were not included in that investigation.…”

Section: Fracture Modesmentioning

confidence: 99%

Tension‐shear interaction of high‐strength bolts during and after fire

Lange

Kawohl

2019

Steel Construction

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Connections in steel structures play an essential role in the structural stability of the entire construction. This is also true in the event of a fire. The difficulty in designing connections for fire lies in the fact that not only material properties, but also loads applied to the connections change depending on temperature. In addition, the temperature‐dependent decrease in the tensile strength of high‐strength bolts does not coincide with the decrease in shear strength. So far, the influence of combined tension and shear loading on high‐strength bolts has not been studied in detail. This project included carrying out interaction tests on high‐strength bolts of property class 10.9 (fu = 1000 N/mm2). Post‐fire performance was examined in addition to observing the loadbearing behaviour during fire. The examinations were completed with additional material tests. The results were compared with earlier research on the temperature‐dependent loadbearing capacity of high‐strength bolts during and after temperature loading as well as on the loadbearing behaviour of bolts in steel structures under combined tension and shear loads. This investigation contributes to a better understanding of the loadbearing capacity of high‐strength bolts under combined loading during and after a fire.

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Residual mechanical properties of high strength steel bolts subjected to heating-cooling cycle

Cited by 50 publications

References 19 publications

Thermal Behavior of Tunnel Segment Joints Exposed to Fire and Strengthening of Fire-damaged Joints with Concrete-filled Steel Tubes

Thermal Behavior of Tunnel Segment Joints Exposed to Fire and Strengthening of Fire-damaged Joints with Concrete-filled Steel Tubes

Çelik Yapılarda Kullanılan Birleşim Elemanlarının Yangın Etkisinin Deneysel Olarak İncelenmesi

Tension‐shear interaction of high‐strength bolts during and after fire

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