Analysis of exterior beam-column joints under varying column axial load and code comparisons

This paper presents a finite element (FE) study of beam-column joints subjected to cyclic loading. This study is primarily dependent on investigating the shear behavior of joints under the influence of different column axial load ratios. Wherefore, a total range of the column axial load ratios, whether in tension or compression has been considered. This paper proposes a two-dimensional (2D) FE model that considers material non-linearity. The proposed FE model was verified with experimental results from literature that tested varying column axial load ratios and different failure modes. The examination among experiential and numerical outcomes demonstrated that the FE model can reenact the conduct of beam-column joints and can catch the different failure modes with acceptable accuracy. A parametric study was established using the proposed FE model and strut-and-tie (ST) model of Pauletta to assess the Eurocode joint shear strength equations. For this purpose, four specimens were designed according to Eurocode recommendations while two other specimens were designed to satisfy all of the Eurocode recommendations except for the required joint confinement. An interaction diagram was introduced for each specimen to express the behavior under varying column axial load ratios. The results of the comparison between Eurocode, FE model, and ST model showed some differences in calculating the joint shear strength capacity, especially under column tension loads. Furthermore, this paper proposed new design equations based on Eurocode equations taking into account the column axial load effect. These proposed equations worked to increase the accuracy in calculating the joint shear strength capacity. Proposed equations were compared to the FE model results and other experimental results available in the literature. The comparison showed that the differences with the FE model decreased and that the proposed equations had better accuracy at different tension and compression loads than the Eurocode.

Perbandingan Kekuatan Kolom Berdasarkan SNI 2847:2013 dan SNI 2847:2019

Today, Practitioners of Civil Engineering in Indonesia are still using SNI 2847:2013 as code for reinforcement concrete design. As we know that SNI 2847:2019 been published, but practitioners still not yet use it.The point of design and evaluation in SNI 2847 code is reduction factor (ɸ) that could influence strength design of structure base on it behaviour. Load in Column is not just axial load, but flexural and combine of axial and flexural. This behavior makes the column has variate reduction factor and it can shown by interaction diagram. This research is compare between SNI 2847:2013 and SNI 2847:2019 for column with section 400x500, fc’ 20 MPa and reinforcement ratio 1%. Result of this research is compare between SNI 2847:2013 and SNI 2847:2019 for column with variation fy is not too significant. So when the column of SNI 2847:2013 inspected or evaluated by SNI 2847:2019 is not distinction.

Construction of Uniaxial Interaction Diagram for Slender Reinforced Concrete Column Based on Nonlinear Finite Element Analysis

Slender reinforced concrete column may fail in material failure or instability failure. Instability failure is a common problem which cannot be analyzed with first-order analysis. So, second-order analysis is required to analyze instability failure of slender RC column. The main objective of this study was to construct uniaxial interaction diagram for slender reinforced concrete column based on nonlinear finite element analysis (FEA) software. The key parameters which were studied in this study were eccentricity, slenderness ratio, steel ratio, and shape of the column. Concrete damage plasticity (CDP) was utilized in modeling the concrete. Material nonlinearity, geometric nonlinearity, effect of cracking, and tension stiffening effect were included in the modeling. The results reveal that, as slenderness ratio increases, the balanced moment also increases, but the corresponding axial load was decreased. However, increasing the amount of steel reinforcement to the column increases the stability of the column and reduces the effect of slenderness ratio. Also, the capacity of square slender RC column is larger than rectangular slender RC column with equivalent cross section. However, the result is close to each other as slenderness ratio increased. Finally, validation was conducted by taking a benchmark experiment, and it shows that FEA result agrees with the experimental by 85.581%.

Verifying the Shear Load Capacity of Masonry Walls by the V Rd–N Ed Interaction Diagram

Verification of shear load capacity is required for all shear walls that take horizontal wind loads, loads imposed by ground action or other non-mechanical (rheological or thermal) loads. Shear walls are exposed not only to shear forces, but also vertical actions caused by dead load or imposed loads as shear walls also usually function as bearing walls. This load combination is quite important as shear load capacity V Rd depends on mean design stresses σd which, in turn, depend on design forces N Ed. Interactions between shear V Rd and vertical load N Ed in shear walls are the consequence of observed combinations of actions in these types of walls. Additionally, the vertical load N Ed acts on the wall at certain eccentricity eEd, which can result in a change in the length of the compressed part of the cross-section l c. This paper describes the procedure for verifying shear load capacity by means of the interaction diagram drawn as specified in Eurocode 6 (prEN 1996-1-1:2017). Necessary equations for determining load-carrying capacity of cross-section against vertical load N Ed were worked out. The effect of wall shape and eccentricity of vertical load on the shape of the interaction diagram was analysed.

Determining criteria interaction and criteria priorities in the freight village location selection process: the experts' perspective in Turkey

PurposeConsidering the contribution of freight villages (FVs) to the economy and sector, transportation cost advantage, environmental externalities, labor costs, employment, etc. criteria evaluation is important in selecting FV location. Environmental sustainability and social dimensions are becoming important criteria for companies in logistics. The purpose of the study is to determine/model the criteria interaction and also determine the criteria priorities in the FV location selection process. Meanwhile, the study aims to evaluate these criteria and present information to researchers and decision makers.Design/methodology/approachSix main criteria and 29 sub-criteria are selected from related literature. Decision making trial and evaluation laboratory (DEMATEL) method is used for determining/modeling the criteria interaction and sketching interaction diagram, and the Analytical Hierarchy Process (AHP) method is used for determining the criteria priorities. One/two-way pairwise compared main/sub-criteria views are obtained from 48 experts for calculations.Findings“Trade potential”, “transportation networks” and “economic factors” have the highest priorities, respectively, out of six main criteria, and they have the most powerful interactions that put these criteria to the center of decision process. Sub-criteria of “foreign trade potential”, “proximity to the port”, “market opportunities” and “proximity to the railway” out of 29 have a total 36.42% priority, more than one-third of the importance.Originality/valueCriteria are evaluated in FV location selection for FV sustainability using criteria interaction diagrams, affecting/being affected by the level of each criterion and their priorities. This study shows a hybrid derivation from DEMATEL-AHP usage methods together. High-volumed and qualified/experienced expert group judgments in Turkey are evaluated.

Carbon fiber reinforced polymer strengthened reinforced concrete square columns under pre-existing eccentric loads

Numerous experimental studies have been conducted on the behavior of strengthened columns, mostly with glued layers of FRP before load application, and rarely under the pre-existing load. Results confirm a good efficiency of strengthening in the compression-controlled region of the columns, as mentioned in design codes and guides such as ACI 440.2R-17. However, their behavior in the tension-controlled region is still a challenging subject. Moreover, when the eccentricity is large enough, the efficiency of the strengthening method needs more attention. This study aimed at strengthening six RC columns in the tension-controlled region under the pre-existing load condition. Furthermore, tested specimens were verified using a nonlinear finite element analysis performed in ATENA software. Moreover, some identical strengthened specimens, which were not subjected to pre-existing load during strengthening, were modeled to capture the effect of pre-existing loads. The results of the analyses were in good agreement with experimental data. Comparison of numerical results obtained for columns strengthened without pre-existing load, and under pre-existing load showed that pre-existing loading significantly reduced the efficiency of FRP jacketing. Also, assuming a linear variation of confinement pressure in the tension-controlled region of the interaction diagram results in good agreement with attained results.