TY - JOUR AU - HUSSEIN, ARDALAN AU - Papp, Ferenc TI - Axial strength of back to back cold formed steel short channel sections with unstiffened and stiffened web holes JF - SCIENTIFIC REPORTS J2 - SCI REP VL - 15 PY - 2025 IS - 1 PG - 18 SN - 2045-2322 DO - 10.1038/s41598-025-15992-9 UR - https://m2.mtmt.hu/api/publication/36297283 ID - 36297283 AB - The increasing adoption of back-to-back built-up cold-formed steel (CFS) channel columns in construction is attributed to their lightweight nature, versatility in shape fabrication, ease of transportation, cost efficiency, and enhanced load-bearing capacity. Additionally, the incorporation of web openings facilitates the integration of electrical, plumbing, and heating systems. These built-up sections are widely utilized in wall studs, truss elements, and floor joists, with intermediate screw fasteners strategically positioned at regular intervals to prevent the independent buckling of channels. Based on 18 experimental tests, this study demonstrates an excellent correlation between finite element analysis and the experimental results, confirming the accuracy of geometrically and materially nonlinear finite element modeling in predicting the axial buckling strength of built-up short columns. Furthermore, the design standards of the American Iron and Steel Institute and Australian/New Zealand Standards were found to underestimate the axial load capacity by approximately 12.5%. The primary objective of this research is to investigate the influence of various hole configurations, both with and without stiffeners, on the axial performance of built-up short CFS channel columns. A total of 180 finite element models were developed, examining four different unstiffened and edge-stiffened hole configurations, validated against experimental results from plain webs. The findings reveal that web holes and edge stiffeners significantly impact axial load-bearing capacity, while the specific shape of the openings has a negligible effect. Specifically, introducing a hole at the centroid of each web results in an approximate 8.5% reduction in axial load capacity in the absence of edge stiffening. However, the incorporation of stiffeners around the perforations mitigates this reduction and enhances both structural efficiency and load-bearing capacity. These results highlight the critical role of edge stiffening in optimizing the structural performance of perforated built-up CFS columns. LA - English DB - MTMT ER - TY - JOUR AU - HUSSEIN, ARDALAN AU - Papp, Ferenc TI - Structural behavior of built-up I-shaped cold-formed steel beams with edge-stiffened holes, unstiffened holes, plain webs, and batten reinforcement JF - RESULTS IN ENGINEERING J2 - RESULT ENGIN VL - 28 PY - 2025 PG - 15 SN - 2590-1230 DO - 10.1016/j.rineng.2025.107545 UR - https://m2.mtmt.hu/api/publication/36370999 ID - 36370999 AB - Perforated cold-formed steel (PCFS) back-to-back channel beams are increasingly gaining popularity in the building sector due to their numerous advantages and economic benefits. Notably, their lightweight nature allows for easier handling and installation, while the holes in PCFS beams facilitate the accommodation of utilities such as electrical and plumbing installations. In this study, a geometrically and materially nonlinear finite element model (FEM) was developed and validated using experimental data from existing literature. The validation results indicated a strong correlation, with the ratios of FEM and Direct Strength Method (DSM) predictions to experimental outcomes being 1.007 and 0.945, respectively. This demonstrates a significant agreement among experimental data, FEM analysis, and moment capacity estimations based on American Iron and Steel Institute (AISI) Standards, although AISI predictions were found to underestimate moment capacities by approximately 5.5 %. Following model validation, an extensive parametric study involving 192 FEM simulations was conducted to evaluate the influence of hole size, hole geometry, edge stiffeners, and batten reinforcements on the moment-carrying capacity of built-up I-shaped CFS beams. The findings indicate that, in comparison with beams having plain webs, the presence of web openings leads to a reduction in moment capacity of approximately 10 %, 9 %, 9 %, and 6 % for circular, slotted, square, and rectangular holes, respectively. Furthermore, the results demonstrate that the inclusion of stiffeners around web openings, together with batten reinforcement, markedly improves the structural performance of PCFS built-up beams. In particular, the maximum enhancement in moment capacity of beams with batten reinforcement and edge-stiffened holes, relative to those with unstiffened holes, is about 9 %, 10 %, 13 %, and 14 % for circular, rectangular, square, and slotted holes, respectively. Overall, the findings offer valuable insights into the structural behavior of perforated built-up CFS beams and emphasize the effectiveness of web hole stiffening and batten reinforcement strategies in mitigating strength reductions caused by web perforations. LA - English DB - MTMT ER - TY - JOUR AU - Vaszilievits-Somjén, Bálint AU - Papp, Ferenc TI - New Buckling Curve for a Compressed Member with Cold-Formed Channel Cross-Section JF - BUILDINGS J2 - BUILDINGS-BASEL VL - 14 PY - 2024 IS - 10 SN - 2075-5309 DO - 10.3390/buildings14103258 UR - https://m2.mtmt.hu/api/publication/35482863 ID - 35482863 N1 - Export Date: 09 January 2025; Cited By: 0; Correspondence Address: B. Vaszilievits-Sömjén; Doctoral School of Multidisciplinary Engineering Sciences, Széchenyi István University, Győr, 9026, Hungary; email: balint.vaszilievits@consteelsoftware.com AB - The verification of a column made from a lipped cold-formed channel section, subjected to pure axial compression relative to the gross cross-section, often results in a combined verification of bending and compression due to the appearance of a shift of the centroid of its effective cross-section. Following Eurocode 3 rules, this requires the determination of two distinct effective cross-sections and various interaction factors. This paper, based on an analytic approach, offers a modification to the actual buckling curve, based on Ayrton–Perry formulation, to include the second-order effects raised by the eventual shift of the effective centroid due to local buckling of the compressed web plate. This eliminates the need to use an interaction formula. The modified buckling curve is verified based on a GMNIA analysis performed on a numerical parametric model, which was previously validated by laboratory tests. In addition, the results are compared with strength results provided by appropriate Eurocode 3 formulas and AISI Direct Strength Method for global-local interaction and with classic experimental results. LA - English DB - MTMT ER - TY - CHAP AU - Vaszilievits-Somjén, Bálint AU - Papp, Ferenc ED - Yancheng, Cai ED - Qiu-Yun, Li ED - Ben, Young TI - FLEXURAL BUCKLING RESISTANCE OF UNIFORM MEMBERS WITH MONOSYMMETRIC C SECTION T2 - PROCEEDINGS OF THE 13TH INTERNATIONAL CONFERENCE ON ADVANCES IN STEEL-CONCRETE COMPOSITE STRUCTURES (ASCCS 2024) SN - 9789887030515 PY - 2024 SP - 1 EP - 4 PG - 4 UR - https://m2.mtmt.hu/api/publication/35787010 ID - 35787010 LA - English DB - MTMT ER - TY - JOUR AU - Nemer, Samer AU - Szalai, József A. AU - Papp, Ferenc TI - The overall imperfection method for fire design situation JF - ENGINEERING STRUCTURES J2 - ENG STRUCT VL - 283 PY - 2023 SN - 0141-0296 DO - 10.1016/j.engstruct.2023.115884 UR - https://m2.mtmt.hu/api/publication/33678493 ID - 33678493 LA - English DB - MTMT ER - TY - JOUR AU - Movahedi Rad, Majid AU - Papp, Ferenc AU - Ibrahim, Sarah Khaleel AU - Szép, János AU - Gosztola, Dániel AU - Harrach, Dániel TI - Elasto-plastic analysis and optimal design of composite integral abutment bridge extended with limited residual plastic deformation JF - SCIENTIFIC REPORTS J2 - SCI REP VL - 13 PY - 2023 IS - 1 SN - 2045-2322 DO - 10.1038/s41598-023-32787-y UR - https://m2.mtmt.hu/api/publication/33756040 ID - 33756040 N1 - Funding Agency and Grant Number: Szechenyi Istvan University (SZE) Funding text: Open access funding provided by Szechenyi Istvan University (SZE). AB - Due to the growing significance of structural theories concerning the composite structure analysed and designed plastically, this paper introduces a new optimisation method for controlling the plastic behaviour of a full-scale composite integral abutment bridge by employing complementary strain energy of residual forces that existed within the reinforcing rebars. Composite bridges are structures made of components such as steel and concrete, which are frequent and cost-effective building methods. Thus, various objective functions were used in this work when applying optimum elasto-plastic analysing and designing the composite integrated bridge structure that was tested experimentally in the laboratory. In contrast, the plastic deformations were constrained by restricting the complementary strain energy of the residual internal forces aiming to find the maximum applied load and the minimum number of steel bars used to reinforce the concrete column part of the structure. The numerical model employed in this paper was validated and calibrated using experimental results, which were considered inside ABAQUS to produce the validated numerical model, using concrete damage plasticity (CDP) constitutive model and concrete data from laboratory testing to solve the nonlinear programming code provided by the authors. This paper presents a novel optimization method using complementary strain energy to control the plastic behaviour of a full-scale composite integral abutment bridge, with the original contribution being the incorporation of residual forces within reinforcing rebars to limit plastic deformations. Following that, a parametric investigation of the various optimisation problems revealed how models performed variously under different complementary strain energy values, which influenced the general behaviour of the structure as it transitioned from elastic to elasto-plastic to plastic; also results showed how the complementary strain energy value is connected with the amount of damaged accrued in both concrete and steel. LA - English DB - MTMT ER - TY - JOUR AU - Hajdú, Gábor AU - Pasternak, Hartmut AU - Papp, Ferenc TI - Lateral-torsional buckling assessment of I-beams with sinusoidally corrugated web JF - JOURNAL OF CONSTRUCTIONAL STEEL RESEARCH J2 - J CONSTR STEEL RES VL - 207 PY - 2023 SN - 0143-974X DO - 10.1016/j.jcsr.2023.107916 UR - https://m2.mtmt.hu/api/publication/33767614 ID - 33767614 N1 - Funding Agency and Grant Number: Hungarian new national excellence program of the ministry for culture and innovations from the National Research, Development and Innovation Fund [UNKP-22-4-II-SZE-10] Funding text: This work was supported by the Hungarian UNKP-22-4-II-SZE-10 new national excellence program of the ministry for culture and innovations from the source of the National Research, Development and Innovation Fund. LA - English DB - MTMT ER - TY - JOUR AU - Hajdú, Gábor AU - Papp, Ferenc TI - Novel formula for the elastic critical moment of beams with corrugated web JF - CE/PAPERS J2 - CE/PAPERS VL - 6 PY - 2023 IS - 3-4 SP - 1705 EP - 1710 PG - 6 SN - 2509-7075 DO - 10.1002/cepa.2614 UR - https://m2.mtmt.hu/api/publication/34139857 ID - 34139857 AB - This paper presents a novel analytical expression to determine the elastic lateraltorsional buckling resistance of I‐beams with corrugated web. The corrugated web beams have higher torsional stiffness than the flat web beams; therefore, the self‐weight of the beam can be reduced. The appropriate hand calculation methods to determine the elastic critical moment of corrugated web beams are based on the modification of warping constant of the cross‐section. In this paper, instead of modifying the warping constant the approximate expression is derived from the total potential strain energy of the beam using an energy method. During the solution, the beam is separated into three parts. The flanges are modelled as thin‐walled beams and the corrugated web is modelled as a thin equivalent orthotropic plate with uniform thickness. To assess the accuracy of the proposed analytical formula full shell finite element models were created in Abaqus software. The accuracy of the proposed expression is examined for sinusoidal and trapezoidal corrugation also. The results of the parametric study showed that the derived formula is accurate and applicable for elastic lateral‐torsional buckling analysis of I‐beams with web corrugation. LA - English DB - MTMT ER - TY - JOUR AU - HUSSEIN, ARDALAN AU - Papp, Ferenc TI - State-of-the-Art: Integrating Fastener Technology and Design Guidelines for Enhanced Performance of Cold-Formed Steel Sections JF - BUILDINGS J2 - BUILDINGS-BASEL VL - 13 PY - 2023 IS - 9 PG - 46 SN - 2075-5309 DO - 10.3390/buildings13092338 UR - https://m2.mtmt.hu/api/publication/34142201 ID - 34142201 AB - Cold-formed steel (CFS) elements have gained significant attention in the field of structural engineering due to their numerous advantages, including high strength-to-weight ratio, cost-effectiveness, and ease of assembly and prefabrication. This review paper presents a comprehensive state-of-the-art analysis of the design and analysis of CFS structures, with a specific focus on columns and beams. The primary objectives and aims of this review paper are to provide a detailed assessment of the factors influencing the behavior and performance of CFS elements, including partial composite action, fastener spacing, bolt arrangement, web aperture, stiffeners, and connection spacing, to propose and present various formulas and methodologies that accurately estimate critical buckling loads, strength, and moment resistance for CFS members, and to emphasize the significance of proper screw and bolt placement in preventing premature failure and enhancing the overall load-carrying capacity of CFS structures. Additionally, the impact of temperature on the mechanical properties and performance of CFS members is discussed. The review paper proposes different formulas and methodologies to accurately estimate critical buckling loads, strength, and moment resistance for CFS members. Moreover, the paper highlights the importance of proper screw and bolt placement to prevent early failure and improve the overall load-carrying capacity of CFS structures. The discussion also emphasizes the need for revisions in existing standards and codes to provide more practical guidelines for designers and engineers. Overall, this state-of-the-art review paper provides valuable insights and recommendations for researchers and practitioners involved in the design and analysis of CFS elements. LA - English DB - MTMT ER - TY - JOUR AU - Vaszilievits-Somjén, Bálint AU - Papp, Ferenc TI - Novel method for the prediction of load bearing capacity of compressed C channels considering interaction of buckling modes JF - CE/PAPERS J2 - CE/PAPERS VL - 6 PY - 2023 IS - 3-4 SP - 1930 EP - 1934 PG - 5 SN - 2509-7075 DO - 10.1002/cepa.2544 UR - https://m2.mtmt.hu/api/publication/34878046 ID - 34878046 AB - The proposed method focuses on the interaction of global and local buckling. A modified Ayrton‐Perry type buckling curve is proposed to calculate the ultimate compression force resistance of centrically compressed cold‐formed C channel. The new buckling curve incorporates both the effects of global imperfections and shift of the center of gravity caused by local buckling of slender web plate of the considered sections. Distortional buckling usually does not play any role for this configuration. LA - English DB - MTMT ER -