Sharif Digital Repository

An experimental investigation is conducted here to study the effects of applying frictional sliding fuses (FSF) in concrete infilled steel frames. Firstly, the influences of some parameters on the behavior of the sliding fuse are studied: Methods of adjusting the FSF for a certain sliding strength are explained and influences of time duration, welding and corrosion are investigated as well. Based on the results, time duration does not significantly affect the FSF, however influences of welding and corrosion of the constitutive plates are substantial. Then, the results of testing two 1/3 scale single-storey single-bay concrete infilled steel frames having FSF are presented. The specimens were... 

In the current work, the results of full-scale laboratory testing of 114.3 and 168.3 mm in diameter steel gas distribution pipes buried at different depths and in two different soil types under a reverse fault offset of 0.6 m are presented and discussed in terms of longitudinal strain distribution, pipe deformation, and cross-section distortion. Results show that the pipe deformation and accordingly its failure mode, and soil failure planes change with increasing burial depth. It was also found that severe cross-section distortion occurs at about 2.3 times the strain limit for onset of wrinkling suggested by various guidelines. © 2017 Taylor & Francis Group, LLC  

In the current work, the results of full-scale laboratory testing of 114.3 and 168.3 mm in diameter steel gas distribution pipes buried at different depths and in two different soil types under a reverse fault offset of 0.6 m are presented and discussed in terms of longitudinal strain distribution, pipe deformation, and cross-section distortion. Results show that the pipe deformation and accordingly its failure mode, and soil failure planes change with increasing burial depth. It was also found that severe cross-section distortion occurs at about 2.3 times the strain limit for onset of wrinkling suggested by various guidelines. © 2018, © 2018 Taylor & Francis Group, LLC  

In this work, microstructural evolutions and mechanical properties of AISI 304L stainless steel were studied after rolling operations at elevated temperatures. Rolling experiments were conducted under warm and hot rolling conditions in the range of 600-1000 °C employing different reductions. Then, the developed microstructures and the mechanical properties of the steel were evaluated by means of uniaxial tensile testing, metallographic observations, and x-ray diffraction method. Besides, two-dimensional finite element analysis coupled with artificial neural network modeling was developed to assess thermo-mechanical behavior of the steel during and after rolling. The results show that... 

In this study, the effect of strain ageing on mechanical properties of warm-rolled steel is investigated. Warm-rolling experiments together with mechanical testing are employed to investigate the effect of processing parameters on the ageing kinetics during and after warm rolling of a low-carbon steel. To do so, the occurrence of dynamic strain ageing is first determined by means of a two-dimensional thermo-mechanical model and then the effect of this phenomenon on the subsequent static strain ageing after warm rolling is studied employing mechanical testing. The results show that the occurrence of dynamic strain ageing during warm rolling may effectively alter the progress of the subsequent... 

This study investigated the effect of intercritical heat treatment temperature on the tensile properties, work hardening and corrosion resistance of dual phase steel. Ferrite-martensite dual phase steel with different martensite volume fractions were obtained after heat treatment at different intercritical temperatures. Microstructure, mechanical properties of steel were measured and the corrosion resistance was evaluated via polarization test. Tensile strength of the specimens increased by increasing the martensite volume fraction up to 48.2%. Further increase in martensite volume fraction led to decrease in tensile strength. Work hardening behavior analyzing showed that in DP steel with... 

The seismic responses of steel water tanks are unconventional given their complex dynamic behavior and the sources of nonlinearity. Therefore, providing a reliable, finite-element model is instrumental in better understanding their dynamic behavior and improving the design conditions. This paper aims to evaluate the seismic performance of steel water tanks using shaking table tests and provide a finite-element reference model for simulating real-size, semi-anchored water tanks by conducting a series of large-scale tests in the Shaking Table Lab of the Sharif University of Technology (SUT). Since scaling the tank requires a difficult process involving changing the liquid density, this paper... 

4340 steel bars were austenitized at 850°C for 1 hour followed by heating at 700°C (ferrite and austenite region) for 90 min and quenching into a salt bath with different temperatures of 300, 350, 400 and 450°C. The steel bars were held for 1 hour at these temperatures before air cooling to room temperature. Various ferrite-bainite microstructures with 34% volume fraction of ferrite and different bainite morphologies were obtained. The results of SEM studies showed that by increasing the austempering temperature, the morphology of bainite varies from lower to upper bainite. According to the T-T-T diagram of the studied steel, the bainite transformation will not complete for the holding time... 

The paper presents the experimental and analytical model analysis of a steel-girder arch bridge. The field test is carried out by ambient vibration testing under traffic excitations. Both the peak picking method in the frequency domain and the stochastic subspace identification method in the time domain are used for the output-only model identification. A good agreement in identified frequencies has been found between the two methods. It is further demonstrated that the stochastic subspace method provides better mode shapes. The three-dimensional finite element models are constructed and an analytical model analysis is then performed to generate natural frequencies and mode shapes in the...