Homogenization techniques are very important in describing the mechanical behavior of high performance composite materials. Among the different techniques applied to this modeling, the RVE ...(Representative Volume Element) and AH (Asymptotic Homogenization) play an important role. In this context, the present work aims to present a complete implementation methodology for Asymptotic Homogenization using ABAQUS® software. Although recent work have provided proper methodologies to describe the mechanical behavior of composite materials based on their constituents, the authors verified that gaps still exist. In contrast, this paper presents all the required steps in details. The application of periodic boundary conditions, which is not straightforward on ABAQUS® software, is described for all the load cases to be solved. The computation of required data from software output files as well as the calculation of the homogenized matrix are also described. The expanded equations to obtain the stresses at microscopic level using finite element commercial software, which could not be seen in recent literature, are detailed and the required emphasis is given. This paper also presents examples to validate and evaluate the obtained results.
•Predicting ultimate shear strength of reinforced concrete deep beams is considered complex for their non-linear behavior.•Traditional prediction methods incapacitate to solve this issue precisely, ...especially if there are openings.•Artificial intelligence algorithms provide the facilities to establish robust predicting model for these structural members.•Support vector regression, multilayer perceptron regressor, gradient boosting regressor, and Ensemble algorithms were tested.•Stacking Ensemble model was the most fitting model among the examined models.
The prediction of nominal shear capacity (Vn) of reinforced concrete (RC) deep beams with web openings is quite complex due to their highly nonlinear behavior. In this paper, Artificial intelligence (AI) methods have been applied to overcome that complexity by providing a reliable predicting model for RC deep beams having web openings. Support vector regression (SVR), multi-layer perceptron regressor (MLP), gradient boosting regressor (GBR), and Ensemble algorithms have been examined on the ten most influential input parameters. Input data includes both experimental results of 179 specimens with various opening shapes and simulated results of 5032 specimens. Among the explored AI algorithms, it was found that Stacking Ensemble showed the best results with a determination coefficient (R2) of 0.998. Finally, it can be concluded that AI algorithms are considered a sufficient and powerful tool for predicting the nominal shear strength (Vn) of RC deep beams with web openings.
•Combining with strain hardening cementitious composites (SHCC) material and honeycombed columns, a novel composite column is proposed, and simulation analysis for axial compression behavior of the ...columns is conducted.•The most vertical load is borne by SHCC, and the steel web basically does not undertake the load.•The holes on the web leads to stress concentration, and a predicted model of yield zone of steel is proposed.•The role of honeycombed web on the composite columns is equivalent to that of lattice plate on the lattice special concrete filled steel tubular columns, and the formula for axial compression bearing capacity of novel columns is derived.
Strain hardening cementitious composites (SHCC) as a newly emerging material has bright application prospect with good ductility and multiple microcracking behaviors. Combining with SHCC new material and new honeycombed steel structures, novel composite columns with steel tube SHCC flanges and honeycombed steel web (STHSC) is proposed in this research. To study the axial compression behavior of STHSC, the finite element model of STHSC is established by ABAQUS. The effects of different parameters on the bearing capacity, ductility and stiffness of STHSC are explored, and the results show that the constraint effect of steel tube has a significant role in ultimate bearing capacity of STHSC. The ductility of STHSC is mainly above 3.50, and STHSC has great initial stiffness. The observed failure mode is categorized into shear failure with local bulging at the middle section. Steel tube has Ludels slip lines and SHCC presents multiple microcracks that lie at an angle of 45 degrees to the edge. The range of expansion displacement for SHCC is from 0.009 to 0.012 times as the length of STHSC. The reasonable model for the yield zone of steel under four stages is described. Moreover, the honeycombed steel web has an excellent role in connecting both flanges, which is equivalent to the effect of lattice plate on the lattice special concrete filled steel tubular columns. Finally, a calculated formula for axial compression bearing capacity of STHSC has been derived with high precision.
Cold-formed steel is being used as a viable substitute for traditional steel and building materials due to its performance, affordability, convenience, lightweight, and environmental friendliness. ...The major purpose of this current research is for a reaction to force-deformation at the connection level to be delivered, which is proper for typical cold-formed steel (CFS) screwed beam-column assembly CFS C-section, and to show the influence of the behavior of CFS under bending test. An inner plate, double angle plate, and self-drilling screws are used by a basic beam-column frame idealized CFS to join the beam-column. Fixed support was implemented at the column base, whereas the beam end had free support. A 0.75 mm cold-formed steel C-section with 80mm height and 30mm width was utilized in this study and assembled into an "I" and "box" configuration. 3d and 4d were used to compute screw spacing for self-drilling screws with 4 mm heads and 2 mm bodies. The first type was each angle plate (top and seat angle) screwed with eight screws, whereas the second involves four screws. The CFS section’s thinness led to the use of screw connections, which are essential to their ability to withstand connection failures, to anticipate the failure mode of the connection segment. Numerical simulation by ABAQUS Student Edition and analytical studies have been conducted by AS/NZS 4600:2018 to investigate the capacity of CFS under bending. Quantity and the arrangement of the screws determine the displacement ductility with tighter spacing enhancing performance and reinforcing global and local buckling resistance.
In order to study the influence of local corrosion on the load-bearing capacity of circular concrete filled steel tube (CFST) long columns under eccentric compression, a numerical model was ...established by using the commercial finite element software ABAQUS. The influence of corrosion site, corrosion volume rate and corrosion area rate on the whole process of load and deformation was discussed, and the sensitivity analysis of the steel strength, concrete strength, eccentricity, steel tube wall thickness and slenderness ratio was performed. It was show that corrosion site and corrosion volume rate have greater impact on ultimate load bearing capacity of circular CFST long columns with localized corrosion, but corrosion area rate has less impact. Under the same corrosion volume rate, the load bearing capacity of CFST columns with localized corrosion at both ends is greater than that at one end which is greater than that at the middle segment. Steel strength, concrete strength, eccentricity, steel tube wall thickness and slenderness ratio can all affect the bearing capacity of the column and corrosion can further degrade it.
•SHCC-strengthened slabs are tested under the effect of drop weight loading.•The location of the SHCC layer at either tension or compression side is investigated.•The effect of surface preparation ...condition is mainly studied.•Impact energy of SHCC-strengthened slabs is obtained numerically using ABAQUS software.•The most favorable surface preparation condition is identified.
In this paper, a thin layer of Strain-Hardening Cementitious Composites (SHCC) is provided in either tension or compression side of RC slabs aiming to improve their impact resistance under the effect of drop weight loading. The main parameter of the current study is the condition of the contact surface between the substrate slab and the SHCC overlay that was prepared by grinding, grinding plus steel dowels or grinding plus epoxy adhesive. Accordingly, 63 RC slabs were prepared and tested under the effect of drop weight falling from three different heights; 1, 1.5 and 2 m. It was found that the SHCC strengthening layer enhanced the impact resistance of the strengthened slab when added at either tension or compression side. However, in order to attain the outermost impact resistance showing ductile performance, it is better to provide a thin layer of the SHCC at the tension side of the slab connected to the substrate slab by epoxy resin applied on pre-prepared grinded surface. Furthermore, numerical simulations based on ABAQUS software package were performed on the strengthened slabs. Their results showed good agreement with the experimental findings from the viewpoint of the kinetic energy. Besides, the impact failure loads were determined numerically for the studied slabs and compared with those obtained from incremental static loading tests.
The purpose of this study is to explore the numerical behavior of circular Reinforced Concrete (RC) short columns with different degrees of confinement with Carbon Fiber Reinforced Polymer (CFRP) ...(0%, 25%, 50%, and 100%) wraps under concentric and eccentric loading. The numerical analysis carried out by using an improved Concrete Damage plasticity (CDP) model implemented in ABAQUS software for finite element (FE) analysis. The FE model simulated a total of twenty-four numerical specimens. The findings were matched to published experimental test results in the literature. The findings of the FE model and the experimental data were good similar. As a consequence, the model was found to be valid. The numerical results shows that as load eccentricity increased, the load carrying capacity of columns decreased for unconfined specimens, whereas the decline in strength for confined specimens becomes limited as the degrees of confinement ratio increased. In addition, increasing the CFRP confinement ratio improves the column's load-bearing capability at the same load eccentricity.
