Flexural Behaviour of Different Stiffener Section Area on Full Height Rectangular Opening Castellated Steel Beam

Vierendeel is one of failure mechanisms in a castellated steel beam. Vierendeel mechanism is the main failure that occurs in a full high rectangular opening castellated beam. Vierendeel decrease castellated flexural capacity compare to the original wide flange section beam. One solution to prevent the vierendeel mechanism is by installing a diagonal stiffener in form of a steel bar on a castellated beam. The research’s purpose is finding the effect of different size of steel bar diameter on the flexural capacity. Four different sizes of steel bar diameter used in this research: 10 mm, 12mm, 16 mm, and 19 mm. Castellated beam flexural capacity is analysed with the method of truss analysis and pushover analysis. This study shows it can be infer that the bigger size of steel bar diameter does not always determine the higher flexural capacity of the castellated beam. Optimum value of the beam’s flexural capacity is affected by the strength of the flange section. The largest increment of flexural capacity between original wide flange compare to the castellated beam is 139.4% by using 16 mm diameter of the diagonal stiffener.

Studi Komparasi Perancangan Balok Struktural Berdasarkan SNI 2847-2002, SNI 2847-2013 Dan SNI 2847-2019

This study aims to determine the difference in structural beam design using SNI 2847-2002, SNI 2847-2013 and SNI 2847-2019 by comparing the bending and shear reinforcement in the case study of the Faculty of Health Sciences Building, University of Borneo Tarakan. The results of the comparisons include: the maximum reinforcement ratio at SNI 2847-2013 and 2019 is around 16,667% smaller than SNI 2847-2002, the flexural capacity of the beam design results from SNI 2847-2013 and 2019 increases by about 12.5% compared to SNI 2847-2002, The shear capacity of concrete (Vc) designed with SNI 2847-2013 and 2019 increased by about 2% compared to SNI 2847-2002, as well as the design shear capacity of the accumulated concrete and shear reinforcement designed by SNI 2847-2013 and 2019 increased no more than 1% compared to SNI 2847-2002.

Finite element modeling of flexural behavior of reinforced concrete beams externally strengthened with CFRP sheets

In this research, the finite element method is used to develop a numerical model to analyse the effect of the external strengthening of reinforced concrete beams by using carbon Fiber Reinforced Polymer (CFRP) sheets. A finite element model has been developed to investigate the behavior of RC beams strengthened with CFRP sheets by testing nineteen externally simple R.C. beams, tested under a four-point load setup until failure. Various CFRP systems were used to strengthen the specimens. The numerical results using the (ANSYS workbench v.19.1) were calibrated and validated with the experimental results. The research results indicate a significant improvement in the structural behavior of the specimens strengthened using CFRP sheet systems. Then the validated model investigated the effect of the width of CFRP sheets, no of layers, and CFRP size on the behavior of strengthened R.C. beams. Results of this numerical investigation show the effectiveness of increase CFRP width to improve the flexural capacity of R.C. beams. An increase in the flexural capacity up to 100 % compared to the control beam.

Comparison of flexural capacity of different hollow slab beams with/without pavement layer reinforced by steel plates

PurposeReinforcement of reinforced concrete (RC) beams in-service have always been an important research field, anchoring steel plate in the bottom of the beams is a kind of common reinforcement methods. In actual engineering, the contribution of pavement layer to the bearing capacity of RC beams is often ignored, which underestimates the bearing capacity and stiffness of RC beams to a certain extent. The purpose of this paper is to study the effect of pavement layer on the RC beams before and after reinforcement.Design/methodology/approachFirst, static load experiments are carried out on three in-service RC hollow slab beams, meanwhile, nonlinear finite element models are built to study the bearing capacity of them. The nonlinear material and shear slip effect of studs are considered in the models. Second, the finite element models are verified, and the numerical simulation results are in good agreement with the experimental results. Last, the finite element models are adopted to carry out the research on the influence of different steel plate thicknesses on the flexural bearing capacity and ductility.FindingsThe experimental results showed that pavement layers increase the flexural capacity of hollow slab beams by 16.7%, and contribute to increasing stiffness. Ductility ratio of SPRCB3 and PRCB2 was 30% and 24% lower than that of RCB1, respectively. The results showed that when the steel plate thickness was 1 mm–6 mm, the bearing capacity of the hollow slab beam increased gradually from 2158.0 kN.m to 2656.6 kN.m. As the steel plate thickness continuously increased to 8 mm, the ultimate bearing capacity increased to 2681.0 kN.m. The increased thickness did not cause difference to the bearing capacity, because of concrete crushing at the upper edge.Originality/valueIn this paper, based on the experimental study, the bearing capacity of hollow beam strengthened by steel plate with different thickness is extrapolated by finite element simulation, and its influence on ductility is discussed. This method not only guarantees the accuracy of the bearing capacity evaluation, but also does not require a large number of samples, and has certain economy. The research results provide a basis for the reinforcement design of similar bridges.

Nonlinear ABAQUS Simulations for Notched Concrete Beams

The numerical simulation of concrete fracture is difficult because of the brittle, inelastic-nonlinear nature of concrete. In this study, notched plain and reinforced concrete beams were investigated numerically to study their flexural response using different crack simulation techniques in ABAQUS. The flexural response was expressed by hardening and softening regime, flexural capacity, failure ductility, damage initiation and propagation, fracture energy, crack path, and crack mouth opening displacement. The employed techniques were the contour integral technique (CIT), the extended finite element method (XFEM), and the virtual crack closure technique (VCCT). A parametric study regarding the initial notch-to-depth ratio (ao/D), the shear span-to-depth ratio (S.S/D), and external post-tensioning (EPT) were investigated. It was found that both XFEM and VCCT produced better results, but XFEM had better flexural simulation. Contrarily, the CIT models failed to express the softening behavior and to capture the crack path. Furthermore, the flexural capacity was increased after reducing the (ao/D) and after decreasing the S.S/D. Additionally, using EPT increased the flexural capacity, showed the ductile flexural response, and reduced the flexural softening. Moreover, using reinforcement led to more ductile behavior, controlled damage propagation, and a dramatic increase in the flexural capacity. Furthermore, CIT showed reliable results for reinforced concrete beams, unlike plain concrete beams.

Experimental Study on the Out-of-Plane Behavior of Brick Masonry Walls Strengthened with Mortar and Wire Mesh: A Pioneer Study

In the past, fiber-reinforced polymer (FRP) composites have been extensively used to modify the structural response of masonry brick walls. The promising advantages of FRP composites are easy application, lightweight, and very high tensile strength. However, FRP composites are very expensive, and their availability is an issue, especially in developing countries. The use of bricks is widespread in developing countries due to their low price and easy availability. Recent earthquakes and research results have demonstrated the vulnerability of existing masonry structures. In this study, we aimed to investigate the use of low-cost and readily available strengthening materials, i.e., cement-sand mortar and wire mesh, to enhance the flexural capacity of cement-clay interlocking brick (CCIB) masonry walls. The proposed strengthening materials were applied in different configurations and thicknesses. The experimental results indicated that using CS mortar and wire mesh is promising to enhance the flexural capacity of CCIB masonry walls. The flexural capacity and energy absorption capacity of the CCIB masonry wall (strengthened with 20 mm thick CS mortar and three layers of wire mesh) were 87% and 46% higher than the reference CCIB masonry wall. The results of this study can be used to improve the performance of masonry structures against earthquakes in the developing regions.