Key Engineering Materials Vol. 1011

Abstract: This study explores the integration of GiD pre-processing software with ETABS to enhance the finite element modeling of large, complex, multi-story buildings under diverse loading conditions. The research highlights the benefits of using GiD for customized meshing of slab systems, which allows for precise control over mesh density and element quality. Through a case study of an eight-story reinforced concrete structure, the study demonstrates how GiD improves analysis accuracy and computational efficiency by reducing process time and minimizing mesh-related errors. The results indicate that GiD’s refined meshing capabilities enhances the structural model’s accuracy, improving load distribution, straining actions calculations, deflection accuracy, and load transfer representation under gravity loads. In addition, GiD’s approach leads to more reliable predictions of natural periods, lateral displacements, and story drifts under seismic conditions. This integration offers valuable insights for engineers seeking to optimize FEA workflows for complex structures.

Abstract: The new generation of Eurocodes for concrete structures, specifically the draft standard FprEN 1992-1-1:2023, introduces an innovative application of non-prestressed Fibre Reinforced Polymer (FRP) reinforcement (Annex R). This standard represents the first standardized method for the application of FRP reinforcement, an area that has been lacking in European standards to date. Composite reinforcement using glass (GFRP) or carbon fibre (CFRP) provides a perspective alternative in specific applications where it can replace traditional steel or stainless steel reinforcement. The main advantages are high corrosion resistance and electromagnetic neutrality. This allows for application in structures exposed to a high level of environmental impact. However, composite reinforcement with glass fibres exhibits sensitivity to alkaline environments and has a lower modulus of elasticity compared to steel reinforcement. Due to the linear elastic stress-strain diagram for FRP reinforcement, the design of structures with FRP reinforcement requires a different approach than traditional concrete reinforcement. The standard FprEN 1992-1-1:2023 provides specific approaches for the design of concrete elements using FRP reinforcement, considering various types of loading. In the context of design resistance to punching shear, the standard offers a specific relationship that determining the punching shear resistance for using longitudinal FRP reinforcement. In situations where it is necessary to consider punching shear reinforcement, the shear reinforcement should not be made from FRP. The transition to the new Eurocode brings significant changes in the method of design punching shear resistance compared to the current standard ČSN EN 1992-1-1. The aim is to verify the accuracy of the newly introduced relationships for punching shear through a real experiment with steel and FRP longitudinal reinforcement. The experiment will also research the effect of the adding FRP stirrups on the overall resistance under local loading conditions.

Abstract: More and more often these days we can see buildings of original shapes, designs and sizes. Buildings with a circular or inter-circular (ring) plan form are no exception. Various combinations of loads or support of ceiling or roof slabs are associated with this, which of course has a fundamental effect on the course of internal forces. The article describes certain anomalies in the course of internal forces connected precisely with the atypical ground plan shape of slab - the annulus. These anomalies were detected by the authors of the article based on the analytical solution of annular slabs, specifically for slabs of an inter-circular (ring) shape. For some types of support and dimensions of the ring slab, unusual courses of bending moments arise, which differ from the expected courses. The mentioned anomalies, or unexpected courses of internal forces must be properly taken into account when designing and assessing structures so that these structures are still safe, reliable and usable.