Sprawozdanie z badań podczas próbnego obciążenia wiaduktu 0-1 przeprawy drogowej przez rzekę Wisłę w ciągu Północnej Obwodnicy Puław
Przedmiotem niniejszego opracowania jest obciążenie próbne wiaduktu 0-1 przeprawy drogowej przez rzekę Wisłę w ciągu Północnej Obwodnicy Puław. Opracowanie zawiera wyniki badań obiektu podczas próbnego obciążenia oraz analizę porównawczą i weryfikację wyników teoretycznych i wyników badań.
The paper includes a case study of modelling a real historic church using the finite element method (FEM) based on laser scans of its geometry. The main goal of the study was the analysis of the causes of cracking and crushing of masonry walls. An FEM model of the structure has been defined in ABAQUS. A non-linear dynamic explicit analysis with material model including damage plasticity has been performed. A homogenization procedure has been applied to obtain the material parameters used in the modelling of masonry. In the numerical analysis, the interactions between the church structure, the foundations and the ground were taken into account. The obtained results match well with the damaged area of the entire structure from the in-situ survey, and it should be highlighted that the proposed FEM model allows for a rather precise identification of the causes and effects of cracking walls in a qualitative sense. Also a brief research summary is presented.
Towards Understanding of Mechanics of Hernia Managed by Synthetic Mesh in Laparoscopic Operation: A Single Case Study
In this paper a research towards understanding of mechanics of ventral hernia operated with the use of Physiomesh Open image in new window implant and SecureStrap Open image in new window staples is described. Experimental and numerical studies are conducted for that purpose. Experimental works cover uni-axial tension tests of the implant samples and of the implant-staples-tissue system. Also experiments on implant-staples-tissue models, representing operated hernia, subjected to impulse pressure loading are performed. Based on that, constitutive model of the mesh has been identified and failure load of the staples has been determined. In the experiments on the operated hernia systems subjected to pressure loading safe loading level has been determined and failure modes connected to higher pressure values have been observed. Finally, in the numerical simulations of the operated hernia model, built according to FEM rules, it has been proved that failures observed experimentally result from exceeding of the load bearing capacity of the staples considered in this study.
The paper concerns flexural buckling and initial post-buckling of axially compressed columns made of aluminium alloy described by the Ramberg-Osgood relationship. The non-linear differential equation of the problem is derived using the stationary total energy principle and the assumptions of classical beam theory within a finite range. The approximate analytical solution of the equation leading to the buckling loads and initial post-buckling equilibrium path is determined by means of the perturbation approach. Numerical examples dealing with simply supported and clamped I-columns are presented, the effect of the material non-linearity on the critical loads and initial post-buckling behaviour in comparison to linear one is discussed too. The analytical results are compared with the FEM solutions to present a good agreement.
Mechanical properties of polyester reinforced PVC coated fabric subjected to biaxial loading of creep type
The goal of the current study is to analyze the basic mechanical properties of the architec-tural fabric VALMEX, which is a composite material built of reinforcing polyester thread families and both sides PVC coated. The material was firstly subjected to biaxial loading of creep type for about 48 hours. The stress levels of the creep loading in two main or-thogonal directions of the fabric (commonly called the warp and fill directions) were in-troduced as follows: 4.6 kN/m, 10.4 kN/m, 16.4 kN/m, 22.4 kN/m, 28.4 kN/m, 34.4 kN/m. After creep loading the specimens were left unloaded for six months and then were subjected to the biaxial tension till rupture. For all the specimens the basic mechanical properties of the material were determined, for the warp and weft directions separately. The change of the obtained parameters shows the influence of biaxial prestress on the me-chanical performance of the VALMEX fabric.
Yago Moreno Jacomini