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.

Flexural Strength Design of Hybrid FRP-Steel Reinforced Concrete Beams

Through proper arranging of a hybrid combination of longitudinal fiber reinforced polymer (FRP) bars and steel bars in the tensile region of the beam, the advantages of both FRP and steel materials can be sufficiently exploited to enhance the flexural capacity and ductility of a concrete beam. In this paper, a methodology for the flexural strength design of hybrid FRP-steel reinforced concrete (RC) beams is proposed. Firstly, based on the mechanical features of reinforcement and concrete and according to the latest codified provisions of longitudinal reinforcement conditions to ensure ductility level, the design-oriented allowable ranges of reinforcement ratio corresponding to three common flexural failure modes are specified. Subsequently, the calculation approach of nominal flexural strength of hybrid FRP-steel RC beams is established following the fundamental principles of equilibrium and compatibility. In addition to the common moderately-reinforced beams, the proposed general calculation approach is also applicable to lightly-reinforced beams and heavily-reinforced beams, which are widely used but rarely studied. Furthermore, the calculation process is properly simplified and the calculation accuracy is validated by the experimental results of hybrid FRP-steel RC beams in the literature. Finally, with the ductility analysis, a novel strength reduction factor represented by net tensile steel strain and reinforcement ratio is proposed for hybrid FRP-steel RC beams.

Strength Optimization of Infant Pop-Up Seat Frame Using Discrete Material and Thickness Optimization

In this paper, the authors proposed an optimal design method for the strength design of infant pop-up seat frame combined with rear seats for infants, children, and adults, not removable booster seats or car seats. Frame strength design was performed using discrete material and thickness optimization (DMTO) method considering high strength steel (HSS) and advanced high strength steel (AHSS). Structural design using the Section 4 link mechanism was performed, and the weakness of the seat frame due to static load was confirmed through finite element analysis. An optimal design criterion was established by carrying out a case study to derive the limiting conditions according to static and dynamic loads. In consideration of these criteria, the optimal design according to d-optimal and discrete Latin-hypercube (DLH) was performed among the design of experiments (DOE). And the strength of the pop-up seat frame for infants according to each DOE was checked, and the strength optimization method was suggested by comparing the lightweight ratio.