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Open Access Article
1 - Vibration-based cable tension estimation using two iterative algorithms: Methodology and experimental validation
Latif Doosti Omid Bahar Mohsen Ghafory-Ashtiany Mohsen ElmiIn this paper, a reliable method based on two iterative algorithms is proposed for the estimation of cable tension forces. In this method, a Finite Element model, considering the cable's geometric and mechanical characteristics, is used in order to obtain mass and MoreIn this paper, a reliable method based on two iterative algorithms is proposed for the estimation of cable tension forces. In this method, a Finite Element model, considering the cable's geometric and mechanical characteristics, is used in order to obtain mass and stiffness matrices. The initial geometric stiffness matrix of the structure is calculated according to the taut string theory, assuming an initial value for the tension force. Furthermore, the natural frequency of the MDOF system is calculated using Ritz Method, and then compared to measured vibration frequencies, which can be obtained by output-only system identification methods. In this method, the difference between the computational and measured frequencies should not exceed the pre-defined threshold, otherwise the iteration process would be repeated after modifying the initial assumption of the cable force. To evaluate the accuracy and the effectiveness of the proposed method, an experimental study was performed on an external cable in the IIEES structural laboratory. Also, existing cable forces of the Hwamyeong cable-stayed bridge in South Korea have been employed. In both cases, the iterative method is compared with common theoretical and empirical equations in the literature. The results have shown that the iterative method is of high accuracy and great applicability, reducing the difference to even less than 2%. Manuscript profile -
Open Access Article
2 - Cold rolling techniques in mechanical splices: Experimental investigations
mohamad reza shokrzadeh Fariborz Nateghi Allahe taleb sadeghianThis study presents a comprehensive evaluation of the performance of oversize threaded splices under cyclic loading conditions. The research includes monotonic tensile testing and cyclic loading experiments to investigate the seismic behavior of the splices. The experim MoreThis study presents a comprehensive evaluation of the performance of oversize threaded splices under cyclic loading conditions. The research includes monotonic tensile testing and cyclic loading experiments to investigate the seismic behavior of the splices. The experimental results demonstrate that the splices exhibit lower values of εu (strain at peak load) in cyclic loading compared to monotonic tensile testing. This suggests that the cyclic response can serve as a conservative lower bound for the mechanical performance of the splices. The findings highlight the importance of considering cyclic loading conditions when determining conservative lower bounds for the design and evaluation of threaded splices. Understanding the behavior and performance of threaded splices under cyclic loading is crucial for ensuring their reliable and safe operation in seismic regions. Manuscript profile -
Open Access Article
3 - The Sensitivity Analysis of the Distance Effect and Explosive Load on Concrete Structures, Considering the Soil-Structure Interaction Effects
Mohammad Emami korandeh Saeed FarokhizadehThe undeniable impact of soil-structure interaction on the behavior of structures, coupled with the increased importance of explosive loads in current global security and social conditions, has led to the modeling and sensitivity analysis of the distance effect and expl MoreThe undeniable impact of soil-structure interaction on the behavior of structures, coupled with the increased importance of explosive loads in current global security and social conditions, has led to the modeling and sensitivity analysis of the distance effect and explosive load on concrete structures, taking into account the effects of soil-structure interaction. Three types of structures with 3, 7, and 15 floors were modeled for this investigation, and the results were evaluated. The software tools ETABS and ABAQUS were utilized, with ETABS for structural element design and ABAQUS for examining the effects of soil-structure interaction. The input energy and induced displacements in the structures have a meaningful relationship with the explosion force. In all three structures (3, 7, and 15 floors), the energy and displacements created vary proportionally with the explosion distance or the reduction in explosive material weight. The plasticity rate reflects a substantial reduction in damage with an increasing explosion distance from the structure. Additionally, according to the research results, an increase in the number of floors undoubtedly leads to more noticeable displacements. Therefore, these displacements and energy absorption in the 15-floor structure exceed those in other structures. The failure zone in the 3-floor structure is mostly in the last floor, in the 7-floor structures in the middle floors, and in the 15-floor structures in the initial floors. Displacement in the 3-floor structure is at the upper levels, in the middle of the 7-floor structure, and at the lower levels of the 15-floor structure. Manuscript profile -
Open Access Article
4 - INVESTIGATING THE SEISMIC PERFORMANCE OF THE HONEYCOMB YIELDING DAMPER(HYD)
peyman shadman heidari Mohammad Ghanooni Bagha Zeinolabedi MortezaaliToday, the use of energy-dissipating system such as yielding metal damper in structures can improve the seismic performance of structures. One of the characteristics of metal yielding dampers is the ability to dissipate high energy and increase the ductility of the stru MoreToday, the use of energy-dissipating system such as yielding metal damper in structures can improve the seismic performance of structures. One of the characteristics of metal yielding dampers is the ability to dissipate high energy and increase the ductility of the structural system, which can improve the ductility and energy absorption characteristics of the metal frame equipped with braces and prevent the brace from buckling during an earthquake. The purpose of this research is introduce a new form of yielding dampers called honeycomb yielding damper (HYD) with different dimensions and thickness along with evaluating and comparing the force-displacement diagrams and investigating the seismic parameters of this type of yielding damper. All modeling and validation of numerical samples were done by Ansys software. Non-linear analysis method is used in this research. The hysteresis curves are obtained under in-plane cyclic loads. The mechanical parameters such as ductility ratio, initial hardness, effective hardness and damping coefficient can be determin. The results of this research showed that the effective stiffness increases by increasing the length and thickness of the sample. The ductility ratio decreases by increasing the height of the sample. the effective stiffness decreases by increasing the height of the sample. The ductility ratio increases by increasing the height of the sample. Also, the effective damping coefficient decreases with the increase in the height of the samples, the effective damping coefficient increases with the increase in length and thickness of the samples. Manuscript profile -
Open Access Article
5 - Study of Scale Effect on Seismic Performance of Steel Plate Shear Wall under Cyclic Loading
abbas akbarpour mohammad memar eftekhari Mehrzad Tahamoli RoudsariThrough recent years, several types of research have been performed about steel plate shear walls numerically, experimentally and a combination of these two methods. Scaled samples have been implemented to make transportation and movement processes easier. However, the MoreThrough recent years, several types of research have been performed about steel plate shear walls numerically, experimentally and a combination of these two methods. Scaled samples have been implemented to make transportation and movement processes easier. However, the accuracy of samples with real scale is of concern. In this research -which has been performed experimentally and by software implementation-, at first, cyclic loading was applied on a single-story, single-span steel shear wall sample made with a one-third scale in the laboratory and then it was modeled in ANSYS and loaded in the same condition. The comparison between these two methods represents an acceptable conformation. After the verification accomplished, various conditions were modeled and analyzed in the software as one-fifth, one-fourth, one-third, one-second, two-third and one scale. The results indicate that averagely, a 25% decrement of maximum shear is observed in the scaled models but the result from contours shows a good conformation in the scaled results and indicates their reliability. Manuscript profile -
Open Access Article
6 - Numerical investigation of settlement effect caused by tunneling on surface structures based on pile group
Alireza Darvishpour Asadollah Ranjbar Karkanaki Hossein Meshki Mohsen ParvizIn this study, an attempt has been made to investigate the effect of various factors on the super structures by modeling the structures based on the pile group and its interaction with urban tunnels. The effect of various parameters such as the presence of pile group, t MoreIn this study, an attempt has been made to investigate the effect of various factors on the super structures by modeling the structures based on the pile group and its interaction with urban tunnels. The effect of various parameters such as the presence of pile group, the horizontal distance of the center of the tunnel from the center of the foundation, the vertical distance of the tunnel to the tip of the piles, the length of the piles and the height of the super structure on the tunnel-soil-structure interaction has been investigated. Based on the analysis, it was observed that the placement of the pile group in the substructure will lead to the reduction of settlement caused by tunneling in the superstructure. From the point of view of the horizontal distance of the tunnel from the center of the superstructure.The location of the structure in the critical range of the tunnel, which includes two lines with the internal friction angle of the soil relative to the vertical, the structure has the greatest impact from tunneling The increase in the length of the piles due to the change in the axial force of the piles increases the period of the foundation and vice versa reduces the settlement of the structure. In general, the side piles in the pile group are less affected by tunneling, but the central pile suffers a significant decrease in axial force. Manuscript profile -
Open Access Article
7 - Investigating the use of PCM on the performance of solar water heaters in cloudy and sunny weather by using nanoparticles in their structure to reduce energy consumption in buildings
Saeed Samadzadeh Baghbani Farivar Fazelpour Hossein Ahmadi Danesh AshtianiPhase change materials in the structure of buildings reduce energy consumption and increase the storage of renewable energies .In this study, in order to investigate the effect of phase change materials on the performance of a solar collector in unstable weather conditi MorePhase change materials in the structure of buildings reduce energy consumption and increase the storage of renewable energies .In this study, in order to investigate the effect of phase change materials on the performance of a solar collector in unstable weather conditions (cloudy weather) in Tehran, numerical simulation of the collector was carried out using Ansys Fluent software. For this purpose, four scenarios were examined and numerically simulated. In the first scenario, the performance of the solar collector was investigated in the stable weather conditions of Tehran city without the use of phase change material. The results showed that the desired solar collector can raise the water temperature to 38 degrees Celsius. In the second scenario, to investigate the effect of air instability and cloudiness on the performance of the collector, it was assumed that the solar radiation will decrease. The results showed that the temperature of the outlet water of the collector decreases from 38 degrees Celsius to 35 degrees with the reduction of sunlight. In the third scenario, the effect of using phase change materials on the performance of the collector in stable weather conditions was investigated. The results showed that the use of phase change material in the collector causes heat storage and increases the water temperature when the solar radiation decreases to 37 degrees Celsius. Also, the use of phase change materials in unstable weather conditions caused the water temperature to increase to 41 degrees Celsius. Manuscript profile -
Open Access Article
8 - Numerical study of the progressive failure of high-rise steel construction with composite roof system under blast load effect
Alireza FaroughiProgressive failure means, failure or total destruction or part of the structure due to the lack of the ability of a part of the structure which to be damaged and not able to distribute overload for the stability and continuity of the structure. Different improvement me MoreProgressive failure means, failure or total destruction or part of the structure due to the lack of the ability of a part of the structure which to be damaged and not able to distribute overload for the stability and continuity of the structure. Different improvement methods are accessible to reach buildings where are vulnerable to events in relation to progressive failure. These procedures are designed to provide the property and health of human life. By adopting the optimum improvement manner, taking into account the economic and technical considerations, it can be reduced the value of financial and life loss caused by the progressive failure. In this study, explosion modeling was performed by the CONWEP program (Conventional Weapons Effects Program) in ABAQUS / CAE software. CONWEP is a loading model based on experimental results, in the ABAQUS software environment. The which is very important, is the involvement of the side openings of the ninth column which is done under the conditions of the removal of the eighth floor column and in the post-blast operating conditions reduces the efforts of the ninth-grade deck girders with tensile performance. Considering that the brackets are in design condition for the maximum operating and ultimate traction modes there is always some overcapacity to the design controller mode, which is mainly pressure, therefore, these added capacities are used under abnormally explosive conditions and eliminate the short- and long-term effects of column removal. Manuscript profile
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