araştırma

ARAŞTIRMA KONULARI:

1. Çelik depo raf kolonlarının basınç ve eğilme altında davranış ve tasarımı

2. Çelik depo raf kolon-kiriş birleşimlerinin statik ve dinamik yükler altında davranış ve tasarımı

3. Depo raf yapılarının deprem yükleri altında davranış ve tasarımı

4. Forklift çarpması etkisi altında depo raf sistemlerinin yapısal davranışı 

5. Çelik depo raf çerçevelerinin statik yükler altında stabilite davranışının incelenmesi

6. Depo raf yapılarının deprem hasargörebilirlik ve risk tespiti

7. Çelik depo raf yapılarının günlük servis yükleri altında yapısal sağlık takibi

Başvurulan, devam eden ve tamamlanan bazı projeler

Seismic Vulnerability and Risk Assessment of Industrial Storage Racking Systems

Industrial storage racking systems (ISRS) are extensively used in regions where seismic risk is high and hence the effective seismic resistant design of new systems and as well as the identification of seismic performance and risk assessment of existing systems is vital primarily for the ISRS users and also for the insurance companies. The current project is being proposed with reference to this important motivation and it will include detailed laboratory testing and numerical analysis studies based on experimentally validated models. As a result of the planned numerical studies seismic fragility curves for storage racking systems will be produced which will lead to the development of risk identification algorithms for loss estimation. Laboratory test program will be planned to carry out physical tests both on members and the system as a whole. The program will be comprised of tests to better understand the structural behavior on element and connection level, pushover tests to investigate the behavior of frames in lateral direction in linear and non-linear regions and finally full scale dynamic tests which would simulate the actual seismic behavior of 3-dimensional systems. Full scale dynamic tests will present the most realistic representation of the actual behavior of the ISRSs providing a thorough understanding of the cyclic behavior of the members and connections within the system as well as the dynamic friction behavior of the stored palletized products.

Investigation of steel storage rack column behaviour under axial compression

The research project focused on the prediction of the load carrying capacity of perforated rack columns using the direct strength method (DSM). The procedure involves the prediction of the elastic buckling loads of members with perforations and the assessment of the accuracy of the DSM buckling curves when applied to storage rack columns with complex cross-sections and with multiple perforations along their length. Very promising results were obtained that would allow substituting the distortional buckling tests, that are currently carried out in the process of design of these columns, by a simple and easy to apply calculation procedure.

Strength of complex cross-section cold formed steel columns with multiple perforations

Steel storage rack columns face difficulties for their design as different manufacturers apply different complex forms of cross-sections with various forms of perforations existing along their lengths. As a result, cold-formed steel storage rack columns cannot be designed based on a unified design method. The non-linear finite element analysis is considered to be the best alternative to experimental testing, but still it cannot be considered as a practical way for design. From this viewpoint, this research study strives to contribute to the determination and use of an analytical procedure for checking the strength and stability of light gauge steel rack columns. By producing additional experimental data regarding the strength of columns within a practical range of column slenderness values, the study provides strong evidence for the validty of a currently suggested analytical formulation for the design of such columns and eliminating the need for physical testing. 

Cyclic behavior and design of steel boltless connections​

Steel storage rack systems play a key role in the industrial supply chain by providing efficient storage spaces for industrial products. Safe storage of products is of vital importance to prevent both economic and possible human life losses. Among various possible reasons that could risk the safety of the systems, one important reason is the earthquake. The flexibility and low-redundancy characteristics of lightweight steel storage racking systems may complicate the behavior of rack frames under lateral seismic effects. In particular, the behavior of the hooked beam-to-column connections (boltless) plays an important role in the seismic behavior of these structures. From this viewpoint, in this resarch work we have focused on the cyclic behavior of the hooked beam-to-column connections and investigate possible practical ways to upgrade the strength and energy dissipation characteristics of existing hooked connections

Investigations on the effect of joint fixity in braced cold formed steel upright frames

Shear stiffness of braced upright frames in steel storage racking systems is an important parameter in identifying the transverse stability and strength of the frames in the cross-aisle direction. It is also directly related to the fixity of the brace member connections to the main upright columns. In this research work, the behavior of steel rack column-to-brace member connections (as applied mostly in North America) was investigated by using Finite Element Analysis under the effects of axial tension and compression on the brace member. Finite Element Analysis models were produced, by using ABAQUS, for two different brace cross-sections and configurations (brace member horizontal or diagonal to the lipped C section column). The brace member cross sections are C sections without lips and for both configurations (horizontal and diagonal) they are welded to the lips of the column in two ways being “flush” and “extended” over the lips. Strength and stiffness of the connections were identified and results were related to the behavior of frames with such connections. 

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