The structural strength requirements for timber buildings have been significantly tightened in the second generation of Eurocodes (EN 1990:2023, EN 1991-1-7), which poses a particular challenge for solid timber frames with a beam-and-column structure, where the transfer of tensile forces via dowel connections is inherently limited. Existing multiscale frameworks for timber post-and-beam robustness lack operational detail at each scale, and no validated workflow currently bridges joint-level continuum damage mechanics and frame-level progressive failure analysis in compliance with the second-generation Eurocodes. This paper addresses this gap by proposing an effective two-scale finite element method (FEM) modelling framework for assessing the strength of such frames during column removal. Existing multiscale models describing the strength of timber structures with beam-and-column systems lack the operational details necessary to integrate failure mechanics at the joint level and progressive failure modelling at the frame level within a single, validated workflow. In this paper, this gap is addressed through three specific contributions: a physically modified quadratic Hashin-type failure criterion for timber, which eliminates the non-physical increase in shear strength under combined stress states perpendicular to the grain; a two-scale structure based on the finite element method (FEM), in which the results of continuous damage mechanics at the joint level directly parameterise non-linear joint elements with six degrees of freedom at the frame level, taking into account coupled directional wear and erosion of the elements; and quantitative validation of both scales against experimental data and the conversion factors for characteristic values of the second generation of Eurocode 5 (prEN 1995-1-1:2023). At the connection level, the simulated strength and stiffness values agree with the experiments to within an error of no more than 5%. At the frame level, the model correctly reproduces the non-linear ‘load–displacement’ relationship, the sequence of joint failure, and the axial forces in the chain line for vertical displacements up to 390 mm, which corresponds to experimental observations.

The present study investigates the shear behaviour of screw-glued and mechanical flange-to-web connections intended for cross-laminated timber (CLT) ribbed panels, with the aim of improving composite behaviour and enhancing the structural performance of long-span timber floor and roof systems. Fifteen CLT-glue laminated timber (GLT) specimens were divided into five groups. One group incorporated SHARP501200 (SHARP) serrated steel plates, while four groups used screw-glued connections manufactured with LOCTITE HB (HB) or LOCTITE HB XE (HB XE) polyurethane (PUR) adhesive used in CLT manufacturing. For the adhesive groups, the screws were installed either from the CLT-flange side or from the GLT-web side to evaluate the influence of the assembly configuration. The specimens were subjected to monotonic quasi-static loading, and the resulting load–slip and load–displacement relationships were evaluated in terms of peak resistance, initial stiffness, post-peak response, and failure mode. The mechanically connected specimens achieved an average maximum load of 39.57 kN, whereas the screw-glued groups ranged from 141.20 kN to 198.90 kN. Installing the screws from the GLT-web side increased the average load-bearing capacity. The screw-glued connections exhibited high initial stiffness and predominantly timber-related failure, while the mechanical connection showed lower resistance and a more gradual post-peak response. Nonlinear finite element models were developed in Verisim4D (V2026), in which the CLT–GLT interfaces were represented by cohesive-zone contact elements governed by a tri-linear shear stress–slip law, consistent with the shear-dominated (Mode II) failure mode observed experimentally for both joint types. The results obtained provide design-relevant parameters and modelling strategies for optimising CLT ribbed panel joints in ultimate and serviceability states, thereby contributing to the development of efficient and environmentally sustainable multi-storey timber structures.

Historical slender steel towers designed before modern fatigue provisions require evidence-based procedures to assess their remaining fatigue life under wind action. This study presents a time-domain fatigue life estimation procedure and applies it to the 368.5 m Riga TV tower, the tallest structure in the Baltic states, completed in 1989. Because the tower’s materials and construction predate current European standards and its height-varying cross-section and closely spaced modes are not well represented by the simplified structural factor of EN 1991-1-4, synthetic wind load histories were generated according to EN 1991-1-4 and the Kaimal turbulence spectrum, including across-wind vortex shedding represented by a simplified lock-in model, and applied to a parametric global finite element model and refined local models of the critical details. The natural frequencies of the global model agree with those identified from geophone and fiber-optic strain measurements, and the computed bending-stress ranges follow the measured trend over the 2–14 m/s range of recorded mean wind velocities. Fatigue damage was evaluated from rainflow-counted stress ranges with the Palmgren–Miner rule and the S–N curve of EN 1993-1-9. For the assessed weld detail the damage is D = 0.081 for a 50-year reference period and 0.060 over the 37 years of service to date, dominated by across-wind oscillations in the second-mode lock-in range at 7–9 m/s. The main limitations are the simplified treatment of lock-in without aerodynamic damping, the assumed structural damping and weld detail category, and the single meteorological record used for the wind exposure; their influence on the result is discussed. The procedure provides a practical, measurement-supported basis for the fatigue assessment of historical steel towers.