Anna Knitter-Piątkowska

This study examines how flute shape and geometric proportions govern the effective transverse shear stiffness of corrugated-board cores. Six profiles are compared at common nominal dimensions and material properties using a strain-energy estimate, the Timoshenko frame model for shear in the corrugation plane, and a membrane-path model for shear along the flute axis. Finite element solutions and mesh refinement provide numerical verification. For the reference configuration, the predicted core shear moduli span 1.52–106.36 MPa in the corrugation plane and 38.20–60.00 MPa along the flute axis. The directional rankings reflect different contributions from axial deformation, bending, and shear along the free flute path. The triangular profile combines the highest frame shear modulus with the lowest material consumption, whereas the rectangular profile gives the highest membrane shear modulus under full plateau bonding. Parametric analyses show that flute height, pitch, and wall thickness affect the two directions differently, with distinct trends for shear modulus and rigidity. The framework provides a reproducible basis for comparing flute geometries within small-strain linear elasticity under rigid face constraints and ideal bonding; predictive accuracy for manufactured board requires experimental validation.

Cyfryzacja sektora budownictwa w ostatnich latach znacząco nabiera tempa, a jednym z jej filarów jest wykorzystanie technologii BIM (Building Information Modeling) jako jednego z rozwiązań usprawniających proces inwestycyjno-budowlany pozwalających na kontrolę na wszystkich etapach realizacji. Kluczowym narzędziem organizacyjnym do zarządzania informacją w środowisku BIM jest dokument BIM Execution Plan (BEP), czyli Plan Realizacji BIM. Jego celem jest koordynacja działań i standaryzacja wymagań dotyczących modelowania informacji o budynku, co przekłada się na efektywniejsze prowadzenie procesu inwestycyjnego. W niniejszym artykule przedstawiono definicję BEP, jego typy, zawartość, podkreślono jego znaczenie praktyczne oraz odniesienia do międzynarodowych i krajowych standardów. Artykuł ma charakter przeglądowy i porządkujący, nie prezentuje wyników własnych badań empirycznych, lecz syntetyzuje aktualne standardy i praktyki stosowania BEP.

The paper presents the problem of damage detection in steel girders. Static displacements at the selected point of the structure play the role of measured variables. Structural response signal decomposition is performed according to the Mallat pyramid algorithm, which is used to perform the discrete wavelet transform (DWT). This procedure allows us to quite well determine the location of structural damage. The geometry and the placement of any defective part of the structure may have a random character. It can be assumed that the random processes occurring in the broadly understood structure mechanics are Gaussian in nature. The first four probabilistic moments are estimated using three approaches independent: semi-analytical (SAM), perturbative (SPT), and Monte-Carlo simulations (MCS). The semi-analytical random approach seems to be the most optimal due to the necessary computation time. The incorporation of the mathematical stochastic apparatus into the classical (deterministic) analysis of the statics of the structure makes it possible to estimate the reliability measures of the analyzed girder.

W artykule przedstawiono studium przypadku porównaniatradycyjnych i nowoczesnych metod inwentaryzacji.Do tego celu wykorzystano pomiary wykonane w budynku A2Politechniki Poznańskiej. W pracy zaprezentowano teoretycznepodstawy inwentaryzacji, rys historyczny budynku, opis porównywanychmetod oraz stosowane urządzenia. Przedstawiono przykładszkicu roboczego oraz problemów, które napotkano podczasobmiarów w metodzie tradycyjnej. Zawarto również skany3D oraz zdjęcia 360 stopni. Dokonano porównania metody tradycyjneji nowoczesnej pod względem dokładności, czasochłonności,kosztów, złożoności procedur oraz zastosowania w trudnychwarunkach. Podsumowanie porównania oraz perspektywyrozwoju zawarto we wnioskach. Skupiono się na możliwościachudoskonalenia dokładności pomiarów, integracji z technologiąBIM, czy zaimplementowania sztucznej inteligencji w inwentaryzacji.Artykuł powstał na bazie pracy inżynierskiej, obronionejna Wydziale Inżynierii Lądowej i Transportu Politechniki Poznańskiejw lutym 2025 roku.

The paper delves into the critical issue of damage detection within the guy cable of a truss steel mast, a pivotal component in structural integrity. It introduces a model wherein damage manifests as a localized cross-section reduction in a single element of the cable. Employing Discrete Wavelet Transform (DWT), a pioneering methodology, the study scrutinizes the behavior of the affected elements through static structural analyses. Signal decomposition via the Mallat pyramid algorithm facilitates comprehensive examination. Static displacements at the connection point between the cable and the truss mast serve as the measured variables. Through systematic investigation, the paper evaluates the impact of damage size and location, external loading force, and cable tension force on the efficacy of the proposed approach. Utilizing data derived from Finite Element Method (FEM) computations for wavelet analysis the authors substantiate the findings with numerical examples, thus offering valuable insights into damage detection strategies for structural health monitoring and engineering applications.

This article presents an extended numerical approach for evaluating the dynamic response of corrugated cardboard transport packaging under simulated transport conditions. Building upon a simplified method previously introduced, this study integrates a more comprehensive Finite Element Analysis (FEA) framework to capture the non-linear behaviour of packaging subjected to vertical random vibrations. The proposed model employs dynamic, modal, and contact analyses to simulate the deformation of packaging and subsequent strength reduction over multiple impact cycles, reflecting real-world conditions more accurately. The developed approach gives detailed insights into the structural degradation of packaging due to repetitive transport loads and validates the findings through comparative compression tests. The results show that enhanced numerical methods improve the accuracy of load-bearing predictions, thereby supporting optimisation in packaging design for various geometries and transport scenarios. This method offers a valuable tool for evaluating the sustainability and cost-effectiveness of packaging solutions in logistics.

The paper presents the problem of damage detection in steel girders. Static displacements at the selected point of the structure play the role of measured variables. Structural response signal decomposition is performed according to the Mallat pyramid algorithm, which is used to perform the discrete wavelet transform (DWT). This procedure allows us to quite well determine the location of structural damage. The geometry and the placement of any defective part of the structure may have a random character. It can be assumed that the random processes occurring in the broadly understood structure mechanics are Gaussian in nature. The first four probabilistic moments are estimated using three approaches independent: semi-analytical (SAM), perturbative (SPT), and Monte-Carlo simulations (MCS). The semi-analytical random approach seems to be the most optimal due to the necessary computation time. The incorporation of the mathematical stochastic apparatus into the classical (deterministic) analysis of the statics of the structure makes it possible to estimate the reliability measures of the analyzed girder.

The paper delves into the critical issue of damage detection within the guy cable of a truss steel mast, a pivotal component in structural integrity. It introduces a model wherein damage manifests as a localized cross-section reduction in a single element of the cable. Employing Discrete Wavelet Transform (DWT), a pioneering methodology, the study scrutinizes the behavior of the affected elements through static structural analyses. Signal decomposition via the Mallat pyramid algorithm facilitates comprehensive examination. Static displacements at the connection point between the cable and the truss mast serve as the measured variables. Through systematic investigation, the paper evaluates the impact of damage size and location, external loading force, and cable tension force on the efficacy of the proposed approach. Utilizing data derived from Finite Element Method (FEM) computations for wavelet analysis the authors substantiate the findings with numerical examples, thus offering valuable insights into damage detection strategies for structural health monitoring and engineering applications.

Currently, the district heating (DH) in Poland is facing many challenges. The business model used hitherto was very simple—in most cities, heating plants produced heat, and centralized heating systems supplied the "product" at a price approved annually by the president of the Energy Regulatory Office (URE). However, recent years have brought significant changes on the market. EU regulations force the elimination of old coal-fired plants that were still built in the Polish People's Republic (PRL), moreover, high prices of CO₂ emission allowances aggravate the financial situation of companies. In addition, in the heating sector, the trend observed in the power sector is becoming increasingly visible—limiting the role of large sources in favor of energy generated locally, closer to the customer. One of the biggest challenges is achieving the targets set by the EU for the share of renewable energy sources (RES) in the heating sector. The present conflicts and problems with the supply of coal and gas are an additional impulse to turn to RES. Thus, the development of sustainable and innovative solutions for energy production and supply at the level of urban networks is currently one of the main technical challenges. The purpose of the paper is to present the current situation and perspectives of development of district heating systems in Poland with a view to the status of district heating in the world, and some deeper insight into European conditions. The review presents energy sources with particular emphasis on renewable energy sources (RES) and their cogeneration for heat production. The examples of existing heating network solutions using renewable energy sources, based on the selected published case studies, are also discussed.

Paper is a material whose mechanical properties are highly dependent on humidity and temperature. Which naturally also builds the relationship between the stiffness and strength of corrugated board and changing weather conditions. In this paper, attention is focused on the dependence of the physical properties of the cardboard on changes in humidity and temperature, which undergo dynamic fluctuations both during the production of corrugated board and during its storage. Two techniques were used to test this effect, namely numerical homogenization and global sensitivity analysis. Both methods were implemented to determine the theoretical relationships between the change in humidity and/or temperature in each layer of corrugated board and its global bending, compression and shear stiffness. The procedure was used to analyze different types of 5-ply and 3-ply cardboard. The obtained results allowed to build a complete map of the relationship between the change in humidity of selected layers and the strength characteristics of the full assembly.