Aug 2026· International Journal of Concrete Structures and Materials· Vol 20· 0 citations· 28 references
Abstract
In the rapid process of urban development, prefabricated segmental lining structures have become one of the primary lining forms for super-large section tunnels due to their advantages such as fast construction speed and ease of quality control. This study employs a combination of similar material model tests and numerical simulations to compare and analyze the effects of the" upper prefabrication + cast-in-place back-arch" segmented design and the "three-part blocks" segmented design on the bearing performance of the lining. The results indicate that the failure modes observed in numerical simulations are highly consistent with those in model tests, with significant damage zones appearing at the crown and springing in both cases, thereby validating the accuracy of the numerical model. During the loading process, the crown and springing, as vulnerable points, were the first to crack when the load reached 0.6 Fu. The vertical displacement response curves of the crown obtained from scaled model tests and numerical simulations were highly consistent, with final values stabilizing at 18 mm. The study reveals that when the flexural rigidity of the joints is less than 40 MN·m/rad, the axial forces and bending moments on the lining in the “three-part blocks” design are significantly reduced, while the lateral displacement in the “upper prefabrication + cast-in-place back-arch” design is smaller. This provides important theoretical support and an experimental foundation for subsequent research on the segmented design of full-scale super-large section tunnels.
This study conducts a preliminary FE simulation of screw piercing and screw rolling processes for producing bimetallic pipes with variable inner and outer positioning and thickness of the corrosion-resistant steel CL (13Cr and 18Cr10Ni grades) as a rational first step before experimental testing. The results demonstrate that a favorable stress–strain state is formed in both processes under the selected deformation parameters (there are no high tensile stresses in the area of high strains and low temperatures). Shape change analysis confirmed that the pipe geometric dimensions according to simulation are sufficiently close to the target values, with only minor deviations in wall thickness and ovality. The change in CL thickness during piercing ranges from 34% to 51% and increases with the elongation ratio. In the rolling process, it reaches approximately 55–56%. The CL position, its thickness and the material choice significantly influence the deformation heating intensity within the bonding of base and clad materials, as well as the magnitude of the forces acting on the tool in contact with the CL. The obtained results can serve as a methodology that lays the groundwork for experimental verification and the further technology implementation, while minimizing risks and costs.
T. Kin, A. Budnikov, Yu. V. Gamin et al.· Modelling· 0 citations
Statement of the problem. Modern construction actively uses prefabricated monolithic and composite structures made of various concretes. In this regard, when assessing the parameters of stiffness and crack resistance, it is necessary to take into account the features of their deformation and cracking at various stages of loading, in particular, the compliance between layers of composite concrete during the formation of not only traditional normal and inclined cracks, but also longitudinal cracks in the intermediate contact zone. Results. A new constructive solution of a prefabricated monolithic frame for residential and public buildings made of industrial П- and L-shaped panel elements, which are combined into a prefabricated monolithic structural system during installation, is presented. The results of numerical studies obtained using the finite element method and special techniques for "grouting" finite elements to account for cracks, the effect of shear and the formation of a longitudinal crack in the inter-mediated contact zone between the prefabricated and monolithic parts of the crossbars of the frame structures under consideration, as well as the effect of the deformation effect in cracks formed in the stretched zone of the composite structure of the crossbar on the parameters of limiting states of the second group. Conclusions. It is established that the values of the opening width of normal cracks in the composite structure of a prefabricated monolithic bolt depend not only on the stresses in the stretched reinforcement caused by bending of the bolt, but also on shear deformations in the inter-mediated contact zone of the prefabricated and monolithic elements of the bolt and the presence of a longitudinal crack between these elements. The values of the opening width of normal cracks obtained taking into account these factors are confirmed by comparing the calculation data with the test results of reinforced concrete frames with prefabricated monolithic crossbars of composite cross section.
V. Moskovtseva, S. Fedorov· Russian Journal of Building...· 0 citations
Pre-Engineered Buildings (PEBs) have emerged as an efficient alternative to conventional steel structures due to their optimized material usage, reduced self-weight, and faster construction. This study presents a comparative analysis and design of tapered sections used in PEB portal frames to evaluate the influence of rafter break point location on structural behaviour. Five different structural models were developed using STAAD.Pro with identical geometry, loading conditions, and design criteria in accordance with ARE 800:2007, IS 875, and ARE 1893:2016. Among the five models, Model I was designed strictly based on bending moment requirements, while the remaining models were configured with varying rafter break points without strict adherence to moment-based design. The analysis includes evaluation of key parameters such as frame weight, bending moment, and support reactions under dead, live, wind, and seismic loads. The results indicate that Model I achieves the minimum structural weight, demonstrating efficient material utilization, whereas Model IV provides improved overall structural performance with better force distribution. It is observed that variation in rafter break point significantly affects bending moment distribution and structural efficiency, while support reactions remain nearly constant across all models. The study concludes that bending moment-based design is essential for achieving economical and optimized PEB structures, while intermediate tapering configurations can enhance overall performance.
Trupti Nandanwar, Mahendra Umare, Pritam Kandikurwar et al.· Journal of Structural Techno...· 0 citations
Perforated and castellated steel beams are widely used due to their high structural efficiency; however, the presence of web openings introduces complex failure modes, such as Vierendeel bending and web-post buckling, which are not observed in solid-web sections. In this study, the influence of geometric parameters on the load-bearing behavior and failure mechanisms of perforated beams with hexagonal openings was systematically investigated. Nonlinear finite element analyses were performed on eleven models, including ten perforated beams with varying opening angles (ranging from 40° to 63°) and numbers of openings, as well as a solid-web reference beam. The numerical modeling approach was validated against experimental data from the literature to ensure the reliability of the results. All models were designed with a constant overall depth, allowing the effects of opening geometry to be isolated from those associated with increased section depth in conventional fabrication methods. The analysis results indicate a direct correlation between beam geometry and failure mode. The primary parameter controlling the transition from ductile, high-capacity flexural failure to brittle, low-capacity shear failure (Vierendeel bending or web-post buckling) is the dimensionless ratio 2dt/dg, where dt is the net section depth and dg is the total beam depth. Models with higher 2dt/dg ratios (such as 0.50 and 0.42) reached 86–92% of the capacity of the solid-web beam by developing a ductile flexural mechanism. In contrast, models with a lower 2dt/dg ratio (0.33) exhibited early brittle failure through the Vierendeel mechanism at 72–79% of the reference capacity, independent of opening angle. The opening angle (θ) was determined to be a secondary parameter. It is concluded that optimizing the 2dt/dg ratio is essential for achieving ductile failure in perforated steel beams and avoiding premature Vierendeel failure.
Orkun Yılmaz, Yusuf Emir Özbal· Dicle Üniversitesi Mühendisl...· 0 citations
The steel-reinforced concrete stiffened transfer system in the Beijing-Hangzhou Grand Canal Museum features a complex annular vierendeel truss and cantilever wall-columns supporting a 9–15 story mountain-shaped frame. To validate its structural performance, static monotonic loading tests were conducted on 1:8 and 1:7 scale models. Results demonstrate that the annular truss exhibits exceptional load redistribution capacity, with internal force ratios varying from 0.4 to 2.4 under uniform loading. The cantilever transfer wall-columns sustained vertical loads up to 2.0 times the design load (2F) without shear failure, displaying a ductile flexural failure mode. Crucially, the maximum mid-span deflection at the factored load (1.35F) was 8.55mm, accounting for only 71.25% of the 12mm serviceability limit. A high-fidelity finite element (FE) model was developed and validated against experimental data, with discrepancies predominantly below 10%. The findings confirm that the proposed system provides high static robustness, effective deformation control, and superior crack resistance, offering a reliable solution for complex high-rise transfers with stringent architectural and functional demands.
Zhicheng Bai, Xiaoxia Zhao, Xuelin Yang et al.· Journal of engineering and a...· 0 citations
Numerical approaches based on the Discrete Element Method (DEM) have proven effective in reproducing complex cracking and failure mechanisms of masonry structures. However, when intending to use them for virtual testing, an important constraint is that their predictive capability strongly depends on the appropriate calibration of material and contact parameters. This study presents the calibration of three-dimensional DEM models developed in 3DEC to simulate in-plane response of full-scale masonry wall with opening, subjected to quasi-static monotonic lateral loading. The experimental results, including the lateral force–displacement relationship, crack patterns and damage mechanisms, are used as benchmark data for the numerical model with exact geometry, boundary condition and loading scenario. Two models were calibrated, composed of rigid blocks and elastic deformable blocks. In both cases the blocks were connected through contact interfaces governed by Mohr–Coulomb joint model. To capture results of the experimental test, a tailored joint-displacement-based softening model is introduced on subcontact scale, representing main novelty of the study. Calibration using the proposed joint model successfully captures the main features of experimental behavior, including initial elastic part, stiffness degradation, peak lateral load, and post-peak softening (including an abrupt decrease in lateral load bearing of the wall at proper displacement), together with experimentally found damage mechanisms. The results demonstrate the capability of DEM-based simulations to reproduce nonlinear in-plane behavior of masonry wall without need for fracture energy parameters and highlight the importance of accurate joint softening models for reliable structural assessment of masonry structures.
Habibollah Katouli, Katalin Bagi· Meccanica (Milano. Print)· 0 citations
We use cookies to run the site and, with your consent, for analytics and to show ads.
See our Cookie Policy.
