Search results for: laminated plates and shells
-
Natural convective heat transfer from isothermal horizontal, vertical and inclined plates - a review
PublicationW artykule przedstawiono przegląd otrzymanych przez różnych badaczy korelacji eksperymentalych, teoretycznych i numerycznych, opisujących wymianę ciepła od izotermicznych płyt o różnym kącie pochylenia. Przedstawiono model matematyczny zjawiska. Opisano stosowane metody badawcze i wskazano przyczyny rozbieżności pomiędzy przedstawionymi przez wielu autorów wynikami.
-
Analysis of magnetic field distribution inside ferromagnetic thin shells during degaussing process
PublicationAnalysis of the demagnetization of a large ferromagnetic object like a ship, was conducted. The approximate mathematical model in the form of a long cylindrical shell of constant magnetic permeability was applied. The discrete degaussing winding was assumed and the current density and magnetic flux density distribution in the ferromagnetic shell wall were determined. Based on the frequential and temporal analysis the recommended...
-
Modelling of wave propagation in composite plates using the time domain spectral element method
PublicationW pracy przedstawiono wyniki obliczeń propagacji fali sprężystej w płycie kompozytowej modelowanej z wykorzystaniem czasowego sformułowania metody elementów spektralnych
-
Application of continuous wavelet transform in vibration based damage detection method for beams and plates
Publication -
Application of continuous wavelet transform in vibration based damage detection method for beams and plates
PublicationW artykule zaprezentowano metodę lokalizacji uszkodzeń w konstrukcjach belkowych i płytowych bazującą na analizie falkowej. Wyznaczono postacie drgań badanych konstrukcji. Postacie drgań konstrukcji belkowej zostały przeanalizowane jednowymiarową transfrormatą falkową. Sformułowano dwuwymiarową transformatę falkową, którą zastosowano do postaci drgań konstrukcji płytowej.
-
Dynamic fracture of brittle shells in a space-time adaptive isogeometric phase field framework
PublicationPhase field models for fracture prediction gained popularity as the formulation does not require the specification of ad-hoc criteria and no discontinuities are inserted in the body. This work focuses on dynamic crack evolution of brittle shell structures considering large deformations. The energy contributions from in-plane and out-of-plane deformations are separately split into tensile and compressive components and the resulting...
-
Free convective heat transfer structures as a function of the width of isothermal horizontal rectangular plates
PublicationZaprezentowano rezultaty badań eksperymentalnych konwekcyjnej wymiany ciepła od izotermicznych płyt prostokątnych skierowanych ku górze. Na podstawie przeprowadzonych wizualizacji zaproponowano dwa modele struktur przepływu. Rozwiązania analityczne dla tych modeli przedstawiono w postaci zależności liczb Nusselta Rayleigh'a. Stwierdzono, że przepływ koncentryczny występuje dla małych wartości liczb Ra, szczególnie w przypadku płyt...
-
Damage detection in 3D printed plates using ultrasonic wave propagation supported with weighted root mean square calculation and wavefield curvature imaging
Publication3D printing (additive manufacturing, AM) is a promising approach to producing light and strong structures with many successful applications, e.g., in dentistry and orthopaedics. Many types of filaments differing in mechanical properties can be used to produce 3D printed structures, including polymers, metals or ceramics. Due to the simplicity of the manufacturing process, biodegradable polymers are widely used, e.g., polylactide (polylactide...
-
Susceptibility to biofilm formation on 3D-printed titanium fixation plates used in the mandible: a preliminary study
Publication -
Review the Ultimate Strength According to Welding Deformation Criteria of Thin Plates Under In-plane Compression
Publication -
Bacterial Inactivation on Concrete Plates Loaded with Modified TiO2 Photocatalysts under Visible Light Irradiation
Publication -
Nonlocal elasticity analysis of moderately thick porous functionally graded plates in a hygro-thermal environment
PublicationThis work performs a novel quasi three-dimensional (3D) bending analysis for a moderately thick functionally graded material (FGM) made of nanoceramics and metal powders, in presence of porosities due to some incorrect manufacturing processes. Such porosities can appear within the plate in two forms, namely, even and uneven distributions. The modeled system assumes a polymer matrix where both shear and transverse factors coexist....
-
Robust four-node elements based on Hu–Washizu principle for nonlinear analysis of Cosserat shells
PublicationMixed 4-node shell elements with the drilling rotation and Cosserat-type strain measures based onthe three-field Hu–Washizu principle are proposed. In the formulation, apart from displacement and rotationfields, both strain and stress resultant fields are treated as independent. The elements are derived in the frame-work of a general nonlinear 6-parameter shell theory dedicated to the analysis of multifold irregular shells.The...
-
The spectral finite element model for analysis of flexural-shear coupled wave propagation. Part 1, Laminated multilayer composite beam
PublicationW pracy przedstawiono model spectralnego elementu skończonego umożliwiającego symulację propagacji fali giętno-ścinającej w materiałąch kompozytowych.
-
Progressive failure analysis of laminates in the framework of 6-field nonlinear shell theory
PublicationThe paper presents the model of progressive failure analysis of laminates incorporated into the 6-field non-linear shell theory with non-symmetrical strain measures of Cosserat type. Such a theory is specially recommended in the analysis of shells with intersections due to its specific kinematics including the so-called drilling rotation. As a consequence of asymmetry of strain measures, modified laminates failure criteria must...
-
Nonlinear FEM 2D failure onset prediction of composite shells based on 6-parameter shell theory
PublicationWithin the framework of the nonlinear 6-parameter shell theory with the drilling rotation and asymmetric stress measures, the modifications of Tsai-Wu and Hashin laminate failure initiation criteria are proposed. These improvements enable to perform first ply failure estimations taking into account the non-symmetric stress measures. In order to check the validity of the proposed criteria, finite element analyses are performed with...
-
Two- and three-dimensional elastic networks with rigid junctions: modeling within the theory of micropolar shells and solids
PublicationFor two- and three-dimensional elastic structures made of families of flexible elastic fibers undergoing finite deformations, we propose homogenized models within the micropolar elasticity. Here we restrict ourselves to networks with rigid connections between fibers. In other words, we assume that the fibers keep their orthogonality during deformation. Starting from a fiber as the basic structured element modeled by the Cosserat...
-
Application of 3D digital image correlation for development and validation of FEM model of self-supporting metal plates structures
Publication -
Study of the chromatographic behavior of selected steroid hormones on aluminum oxide plates based on quantitative structure-retention relationships
Publication -
Nitrogen/Oxygen Enriched Hierarchical Porous Carbons Derived from Waste Peanut Shells Boosting Performance of Supercapacitors
Publication -
Geometrically nonlinear FEM analysis of FGM shells based on neutral physical surface approach in 6-parameter shell theory
PublicationThe paper presents the formulation of the elastic constitutive law for functionally graded materials (FGM) on the grounds of nonlinear 6-parameter shell theory with the 6th parameter being the drilling degree of freedom. The material law is derived by through-the-thickness integration of the Cosserat plane stress equations. The constitutive equations are formulated with respect to the neutral physical surface. The influence of...
-
Corrosion degradation monitoring of ship stiffened plates using guided wave phase velocity and constrained convex optimization method
PublicationThe study presents an experimental investigation on the corrosion degradation level assessment using nondestructive wave-based methods. The degradation level of ship structural elements has been assessed in two different ways. The first one is based on the spectral decomposition and zero-crossing incorporated reconstruction of the dispersion curve approach of the antisymmetric Lamb wave mode and the best matching of the theoretical...
-
The Use of Titanium 3D Mini-Plates in the Surgical Treatment of Fractures of the Mandibular Condyle: A Systematic Review and Meta-Analysis of Clinical Trials
Publication -
Analysis of EN 1993-1-6 guidelines about determining amplitudes of equivalent imperfections of steel cylindrical shells subjected to uniform external pressure
PublicationCivil engineering structures should be designed with reference to relevant standards. One of them is a Eurocode 3 standard EN 1993-1-6:2007: Design of steel structures Part 1-6: Strength and Stability of Shell Structures. According to this standard, the value of buckling load can be determined using different approaches: classical hand calculations (stress design) and geometrical and material non-linear analysis of an imperfect...
-
Numeryczne modelowanie prędkości płynięcia warstw blachy bimetalowej w procesie walcowania = The numerical modelling of the layers flow velocity in bimetal plates rolling proces
PublicationW pracy przedstawiono wyniki obliczeń numerycznych dotyczących procesu asymetrycznego walcowania blach bimetalowych 18G2A+1H13.
-
In Vitro Effect of 3D Plates Used for Surgical Treatment of Condylar Fractures on Prostaglandin E2 (PGE2) and Thromboxane B2 (TXB2) Concentration in THP-1 Macrophages
Publication -
TEM, EDS and optical microscope images of pristine and silica-coated bismuth oxide (Bi2O3) and gadolinium oxide (Gd2O3) structures.
Open Research DataData consists of raw TEM/EDS and optical microscope images of pristine and silica-coated bismuth oxide (Bi2O3) and gadolinium oxide (Gd2O3) structures. Additional TEM images and optical microscope images of silica shells were included.
-
Architectural and Urban Planning Solutions for the Protection of Heritage Buildings in the Context of Terrorist Attacks: Following the Example of Passive Protection Systems
PublicationEvents in recent years showing numerous terrorist attacks raise awareness regarding the neces-sity of considering the safety of heritage buildings. The analysis of available data allows us to conclude that it is not possible to fully prevent terrorist attacks. On the other hand, it is possible to minimize the impact of such incidents through proper design of Passive Protection System (PPS) components. One possible architectural...
-
EMISJA AKUSTYCZNA JAKO SYGNAŁ DIAGNOSTYCZNY ODWZOROWUJĄCY ZMĘCZENIOWE ZUŻYCIE WARSTW ŚLIZGOWYCH PANWI ŁOŻYSK GŁÓWNYCH I KORBOWYCH SILNIKÓW O ZAPŁONIE SAMOCZYNNYM
PublicationW artykule przedstawiono wyniki badań laboratoryjnych, z których wynika, że emisja akustyczna (EA) może być uznana za sygnał diagnostyczny, przydatny do identyfikacji stanu technicznego łożysk głównych i korbowych okrętowych silników o zapłonie samoczynnym. Wykazano w nim bowiem, że parametry emisji akustycznej takie jak: czas rejestracji, energia sygnału, amplituda sygnału, ilość przekroczeń poziomu dyskryminacji, czas narastania,...
-
Measurements of ultrasonic bulk and guided wave propagation in additively manufactured cubes and plates obtained by ultrasonic pulse velocity analyzer and scanning laser vibrometry
Open Research DataThe DataSet contains the results of measurements of ultrasonic wave propagation in additively manufactured samples made of polylactic acid (PLA). Three types of raster angles in two consecutive layers were assumed: 0°/90° (#1), 45°/-45° (#2) and 90°/90° (#3) with respect to the x-axis. For each printing variants a cubic sample (#C1-3) with dimensions...
-
PRE-FAILURE CONDITION AND THE METHOD OF REPAIRING GLUED TIMBER ROOF BEARS
PublicationDesign documentation of glued-laminated timber roof girders is in many cases very general, does not contain details and design solutions, and the contractors do not have experience in the implementation of this type of structure. Design and execution errors, including those related to glued laminated timber roof girders, not only affect the safety and durability of the structure of the facility in which they were built in, but...
-
A Nonlinear Model of a Mesh Shell
PublicationFor a certain class of elastic lattice shells experiencing finite deformations, a continual model using the equations of the so-called six-parameter shell theory has been proposed. Within this model, the kinematics of the shell is described using six kinematically independent scalar degrees of freedom — the field of displacements and turns, as in the case of the Cosserat continuum, which gives reason to call the model under consideration...
-
Local and global response of sandwich beams made of GFRP facings and PET foam core in three point bending test
PublicationIn the paper behaviour of laminated sandwich beams (FRP face sheet – PET foam core – FRP face sheet) subjected to three point bending is studied. The paper aim is to find practical descriptions enabling effective and accurate estimation of the elastic response, damage and failure of the beams, basing on experiments and static calculations. Therefore a number of tests are described, that were done on laminated coupons and foam specimens...
-
The Influence of Global Corrosion Degradation on Localized Damage Detection Using Guided Waves
PublicationThis paper presents the results of a numerical analysis of the influence of corrosion degradation of metal plates on the wave propagation phenomenon. There are several different corrosion types, but general and pitting corrosion are the most common. General corrosion is more or less uniformly distributed over the entire exposed surface of the metal while pitting corrosion takes the form of localized cracks. Because the general...
-
Imaging polarimeter with high-accuracy measuring principles in crystal optics
PublicationAn imaging polarimeter based on the principles of high-accuracy polarimetry well known in crystal optics is proposed. The application of scientific digital cameras for performance light measurements leads to precise data on polarizers quality, i.e., maps of extinction ratio and transmission axis. Processing of numerous images, acquired at various settings in the polarizer-sample-analyser system, allows to determine the two-dimensional...
-
Implementacja pomierzonych imperfekcji geometrycznych powłokicylindrycznej do modelu obliczeniowego
PublicationThis paper presents the method of implementation of the geometrical imperfections used by the author during the experimental and numerical research into the load-carrying capacity of cylindrical steel shells subjected to uniform circumferential compression.
-
Nieliniowa statyka 6-parametrowych powłok sprężysto plastycznych. Efektywne obliczenia MES
PublicationGłównym zagadnieniem omawianym w monografii jest sformułowanie sprężysto-plastycznego prawa konstytutywnego w nieliniowej 6-parametrowej teorii powłok. Wyróżnikiem tej teorii jest występujący w niej w naturalny sposób tzw. stopień 6 swobody, czyli owinięcie (drilling rotation). Podstawowe założenie pracy to przyjęcie płaskiego stanu naprężenia uogólnionego na ośrodek typu Cosseratów. Takie podejście stanowi oryginalny aspekt opracowania....
-
Ethylene decomposition on TiO2 under UV
Open Research DataData contain chromatograms recorded during decomposition of ethylene over TiO2 in a flow reactor under UV irradiation. Semilac UV lamp with total power of 72 W was used as a source of UV light. Chromatograms were recorded in Trace GC Ultra chromatograph equipped in FID detector. Sampling was realised via the dosing sample loop. TiO2 was coated on the...
-
Metodyka badań rozwojowych nowego typu silników i pomp satelitowych
PublicationResearch and development of new type satellite motors and satellite pumps SM with small geometrical displacement, from 5 to 73 cm3/rev, has been conducted in cooperation with Stosowanie Maszyn company from Katowice (manufacturer of motors and pump SM). The improvement of construction of those machines, especially construction of axial compensation and construction of fluid distribution channels have been the main problem of research...
-
FE analysis of support-specimen interaction of compressive experimental test
PublicationThe objective of this work is to investigate the support-specimen interaction during the compressive experimental testing of stiffened plates. The interaction is analyzed employing the nonlinear Finite Element Method using the commercial software ANSYS. The connection between the stiffened plate and testing supports is modelled with the use of contact elements, where several possible interaction scenarios are investigated, and...
-
Nondestructive corrosion degradation assessment based on asymmetry of guided wave propagation field
PublicationThe article presents the results of numerical and experimental investigation of guided wave propagation in steel plates subjected to corrosion degradation. The development of novel procedures allowing for the assessment of the corrosion degradation level is crucial in the effective diagnostics of offshore and ship structures that are especially subjected to aggressive environments. The study’s main aim is to investigate the influence...
-
Modal properties identification of a novel sandwich footbridge – Comparison of measured dynamic response and FEA
PublicationA modern sandwich composite footbridge made of high-tech materials, being an example of practical application of laminated composites in civil engineering, is presented. The in situ non-destructive testing of the footbridge, aiming to identify modal properties and pedestrian comfort, is described. The measured eigenmodes and eigenfrequencies are compared with numerically estimated values. Finite element analyses of the footbridge...
-
FEM simulation of laminate failure in the three point bending
PublicationThe paper presents a FEM simulation of failure of laminate subjected to the three point bending. The numeri-cal model is based on the equivalent single layer approach with 6-paramater non-linear shell theory kinematics. It is implemented in the non-commercial FEM code. The failure initiation is detected with the use of Tsai-Wu criterion. After the failure onset the progressive failure process is modelled through the appropriate...
-
A comprehensive assessment of environmental pollution by means of heavy metal analysis for oysters' reefs at Hab River Delta, Balochistan, Pakistan
PublicationThe heavy metal pollution status of oyster reefs has been assessed with respect to ten metals pollutants in seawater, sediments, and tissues of above two oysters (soft tissues and shells) for assessing the pollution status in a short food chain in Hab River Delta. The results showed that heavy metals accumulated in M. bilineata were higher than those in M. cuttackensis. Simultaneously, the population of M. bilineata species has...
-
Effect of ectoine on hydration spheres of peptides–spectroscopic studies
PublicationIn this paper, we use FTIR spectroscopy to characterize the hydration water of ectoine, its interactions with two peptides–diglycine and NAGMA, and the properties of water molecules in the hydration spheres of both peptides changed by the presence of the osmolyte. We found that the interaction of ectoine with the peptide hydration shells had no effect on its own hydration sphere. However, the enhanced hydration layer of the osmolyte...
-
Mechanical Properties of Aluminium Bracket Strengthening
PublicationThe aim of the research is laboratory investigation of aluminium brackets employed to fasten lightweight curtain walls to building facilities. Tensile loads perpendicular to end plates (vertical) were applied here. The author focused on the solutions intended to increase the load-carrying capacity of aluminium brackets applying the plain washer form A (DIN 125; ISO 7089), plain washer with an outer diameter about 3d (DIN 9021;...
-
Experimental and numerical investigations of ultimate strength of degradated structures
PublicationThe presented work investigates the corrosion influence on the structural behaviour of structural elements. Nine welded large-scale stiffened plates, and 30 standard small specimens have been subjected to the accelerated marine immersed conditions. After corrosion testing, the specimens have been accurately measured in terms of surface characteristics. The coupon specimens were furtherly subjected to tensile loading to develop...
-
Zagadnienia tribologiczne w hamulcu silnika hydraulicznego
PublicationPrzedmiotem badań był prototypowy hamulec cierny wielopłytkowy do silnika satelitowego SM-0,6 o teoretycznej objętości roboczej 16,7 cm3/obr. Hamulec ten zbudowany był z 27 tarcz ciernych wykonanych z materiału TOLOX oraz z pakietu sprężyn talerzowych zamontowanych w układzie X. Zablokowanie hamulca następuje w skutek siły docisku pakietu sprężyn talerzowych płytek ciernych co następuje w chwili spadku ciśnienia w komorze tłoka...
-
Influence of the notch rounding radius on estimating the elastic notch stress concentration factor in a laser welded tee joint
PublicationIn recent years an increased interest of industry in sandwich-type metal structures can be observed. These structures consist of thin plates of 2.5 mm in thickness separated by stiffeners of different shapes and forms. Welds joining the plates and stiffeners are made on the outer side of the plates using laser welding technique. A locally focused source of heat causes the plate to melt creating a very narrow and elongated joint....
-
Indoor accelerated controlled corrosion degradation test of small- and large-scale specimens
PublicationThe work presented here is a part of a long-term project analysing the structural behaviour of ageing marine structures. An accelerated corrosion degradation set-up was developed to reproduce corroded marine structural specimens of different degrees of degradation, controlling various natural factors, i.e., temperature, oxygen content, salinity, and flow velocity. The nine stiffened plates of 1.2 m length and 30 small scale specimens...