Abdulkadir Cüneyt Aydin

Prediction of concrete elastic modulus using adaptive neuro-fuzzy inference system

The prediction of elastic modulus is one of the fundamental facts of structural engineering studies. The performance of adaptive neuro-fuzzy inference system (ANFIS) for predicting the elastic modulus of normal- and high-strength concrete was investigated. Results indicate that the proposed ANFIS modeling approach outperforms the other given models in terms of prediction capability. According to the results, the ANFIS approach is a viable tool for modeling the elastic modulus, as it results in more accurate predictions.

Experimental model for predicting the semi-rigid connections’ behaviour with angles and stiffeners:

This article presents the experimental results of nine specimens of steel bolted beam-to-column connections with top-and-seat angle and stiffener. All of the connections have the angles and beams reinforced with stiffeners in the extended parts. The results are analysed on the basis of the global moment–rotation curves. The main parameters observed are the failure modes, the evolution of the resistance, the stiffness, the rotation capacity, the ductility of a joint and the energy dissipation. The aim was to provide necessary data to improve the Eurocode 3. While the stiffness decreased with the increased thickness of beam stiffeners of 5–10 mm, the maximum bending moment (Mj.max) increased with the increased length of top-and-seat angle.

Longitudinal Imperfections on Thin Walled Cylindrical Shells

Buckling and post-buckling are among the most important failure factors in thin walled structures. The loadcarrying behavior of cylindrical thin-walled shell structures under external pressure load is strongly dependent upon the nature and magnitude of the initial imperfections. These imperfections are invariably caused by an assortment of manufacturing processes like installing or welding. One of the most important imperfections caused by welding that has been reported to have an essential detrimental effect on the buckling resistance of these shells under external pressure load is longitudinal imperfections. Buckling and post buckling capacity of the shells depend on the H/R and t/ R ratios (H the height, R the radius and t the thickness of a cylindrical shell). The present work discusses the finiteelement models labeled as SS (Shallow Slim), DS (Deep Slim), ST (Shallow Thick) and DT (Deep Thick). The samples of first group are modified to include a line longitudinal imperfection, amplitudes of 0.5t, 1t, 2t, 3t, 4t and 8t in depth (t is the thickness of cylindrical shell). The results presented are in agreement with international codes and theories concerning buckling.

Installation and Maintenance Principles of Seismic Isolators: Erzurum Health Campus

RESEARCH ARTICLE Installation and Maintenance Principles of Seismic Isolators: Erzurum Health Campus Merve Sağıroğlu, Mahyar Maali and Abdulkadir Cüneyt Aydın Erzurum Teknik Üniversitesi, Mühendislik Mimarlık Fakültesi, İnşaat Mühendisliği, Erzurum, Turkey Gençler Metal A.Ş., 1. Organize Sanayi Bölgesi, Erzurum, Turkey Atatürk Üniversitesi, Mühendislik Fakültesi, İnşaat Mühendisliği, Erzurum, Turkey

Experimental Behavior of Bolted T-Stub Connections with IPE Standard Profile

In this research, new connection types were suggested, and their behaviors were determined using full-scale experiments. T-shaped combinations created using the IPE standard profile and T-shaped elements are different from those in the literature, which utilize welded plates. Thus, problems occurring at the welds of connections such as the occurrence of fracture points and inability to perform well in place are expected to be eliminated. To recommend the use of weld-less T connections, knowledge of the behavior of the connections was needed. In addition, in this research, the effects of changes in the dimensions of the connection members on the connection behavior were examined for the T-connection type. This provided information about the optimum sizes of the connection elements. The main parameters observed were the evolution of the resistance, stiffness, rotation capacity, ductility of a joint, and energy dissipation. The aim was to provide the necessary data to improve Eurocode 3 and efficiently use residue IPE standard profiles, rather than send them back to the consumption cycle.

Borlu aktif belit çimentolu betonun hidratasyon özellikleri

Bu calismada, Borlu Aktif Belit (BAB) cimentolu betonlarin hidratasyon isilari ve hizlari yari adyabatik yontem kullanilarak belirlenmistir. BAB cimentolu beton uretimi teori ve analizinin gelistirilmesinden sonra, BAB cimentolu betonun hidrasyon isisi analiz edilmistir. BAB cimentosuyla beraber 6 farkli cimento tipi uzerinde de ayni deneyler tekrarlanmis ve hidratasyon ozellikleri belirlenmistir. Cimento tiplerine ait hidratasyon isi-zaman, hidratasyon hizi-zaman grafikleri butun cimento tipleri icin karsilastirmali olarak hazirlanmistir. Ayrica hidratasyon ozellikleriyle dayanim iliskilerini belirleyebilmek amaciyla isil islem gormus ve gormemis 3 farkli cimento tipindeki betonlara; basinc dayanimi, Schmidt cekici, birim agirlik gibi cesitli deneyler uygulanmis ve deney sonuclari grafikler yardimiyla yorumlanmistir. Sonuc olarak BAB cimentolu isil islem gormus ve gormemis betonlarin hidratasyon ozellikleri karsilastirmali olarak analiz edilmis olup BAB cimentolu harc numunelerinin hidratasyon isilarinin diger cimento tiplerinden oldukca dusuk oldugu tespit edilmistir. Bu durumun nedeni olarak, borlu aktif belit cimentosundaki Alit (C3S) fazinin olmayisi ve (C3A) Belit iceriginin dusuk oldugu degerlendirilmistir.