displaying 1000 best results Help
Search results for: LINEAR/NON-LINEAR ELASTIC MATERIAL
-
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...
-
Weakly non-local theories of damage and plasticity based on balance of dissipative material forces
PublicationWykazano, że założenie o siłach materialnych oraz odpowiadających im równaniach równowagi w połączeniu z klasycznymi prawami dynamiki w przestrzeni fizycznej, pozwoliło na sformułowanie teoretycznych podstaw w zakresie słabo-nielokalnych gradientowych modeli zniszczenia i plastyczności. Odpowiednie równania równowagi w przestrzeni fizycznej i materialnej oraz pierwsze i drugie prawo termodynamiki zapisano w postaci całkowej. Następnie...
-
Catalytic conversion of linear low density polyethylene into carbon nanomaterials under the combined catalysis of Ni2O3 and poly(vinyl chloride)
Publication -
SU-FF-T-284: Linear Energy Transfer (LET) Dependence of BANG® Polymer Gel Dosimeters in Proton Beams
Publication -
Acute effects of unilateral and bilateral conditioning activity on countermovement jump, linear speed, and muscle stiffness: A randomized crossover study
Publication -
Evaluation the environmental fate of pharmaceuticals using a level III model based on poly-parameter linear free energy relationships
PublicationOpisano możliwości zastosowania modelu ''Level III Model'' do opisu losu środowiskowego pozostałości farmaceutyków w środowisku. Zastosowany model umożliwia oszacowanie trwałości, stężeń oraz transportu poszczególnych zanieczyszczeń pomiędzy poszczególnymi elementami składowymi środowiska (powietrze, woda, gleba i osady denne).
-
Sensitivity analysis of critical forces of trusses with side bracing
PublicationThe present research is devoted to the study of out-of-plane buckling of trusses with elastic side bracing. Inthis paper, a sensitivity analysis of critical buckling loads of a truss due to bracing stiffness is carried out. A method based on the sensitivity analysis for the determination of the threshold bracing stiffness conditionfor full bracing of a truss is proposed. The influence lines of the unit change of the bracing stiffness...
-
Influence of Wood Moisture on Strength and Elastic Modulus for Pine and Fir Wood Subjected to 4-point Bending Tests
PublicationThe main purpose of this research paper was to determine the influence of the wood moisture on the strength and elastic modulus of pine and fir wood specimens subjected to the 4-point bending tests. Six bending tests for each wood species and for two different moisture level have been performed. Then, the advanced statistical analysis of the results has been carried out. On the basis of the obtained results, it has been noted that...
-
Anti-plane surface waves in media with surface structure: Discrete vs. continuum model
PublicationWe present a comparison of the dispersion relations derived for anti-plane surface waves using the two distinct approaches of the surface elasticity vis-a-vis the lattice dynamics. We consider an elastic half-space with surface stresses described within the Gurtin–Murdoch model, and present a formulation of its discrete counterpart that is a square lattice half-plane with surface row of particles having mass and elastic bonds different...
-
Analiza trwałości zmęczeniowej asfaltów drogowych i modyfikowanych z wykorzystaniem testu liniowego zwiększania amplitudy / Analysis of the fatigue life of neat and modified bitumens using linear amplitude sweep test
PublicationThe paper presents an evaluation of the fatigue resistance of selected Polish bituminous binders: neat bitumen 50/70, polymer modified bitumen PMB 45/80-55 and polymer highly modified bitumen PMB 45/80-80. The linear amplitude sweep (LAS) test, which is a new bitumen performance grading test developed in the USA, and was used to assess the fatigue life of the bitumens. Highly modified bitumen 45/80-80 showed 10-20 times higher...
-
Cross sections calculations for electron scattering from dimethylamine, NH(CH3)2, molecule
PublicationThe total cross section for single electron-impact ionization and the integral elastic cross section for electron scattering from dimethylamine have been calculated using the binary-encounter-Bethe model and the independent atom method, respectively.
-
The luminescence study of Sc2(1–x)Ga2xO3:Cr3+/4+ coumpounds
Open Research DataThe growing interest in the use of near-infrared (NIR) radiation for spectroscopy, optical communication, and medical applications spanning both NIR-I (700–900 nm) and NIR-II (900–1700 nm) has driven the need for new NIR light sources. NIR phosphor-converted light-emitting diodes (pc-LEDs) are expected to replace traditional lamps mainly due to their...
-
DYNAMIC MECHANICAL BEHAVIOUR OF GFRP COMPOSITES WITH SiO2 NANO PARTICLES REINFORCED EPOXY MATRIX
PublicationDynamic mechanic (DMA) tests were performed to compare the mechanical behaviour of glass fibre reinforced epoxy laminate composites with SiO2 nanoparticle reinforced matrix. The selection of the most promising nanoparticle concentrations was considered in terms of elastic modulus and glass transition temperature. The reference specimens (0% nanoparticles) did not contain diluent accordingly the results do not allow the exact comparison...
-
Adhesive compliance effect in mode I separation:Profilometry approach
PublicationThe effect of adhesive compliance on the deflection of a loaded, bonded beam was studied using laser profilometry. Experimental data obtained were compared with both Euler-Bernoulli (encastré) and Winkler (one parameter elastic foundation) models. A third, analytical, 2D model, based on shear within the adhesive layer (two parameter elastic foundation), was introduced. Finite element analysis (FEA) was also used to study the effect...
-
Damage detection in plates based on Lamb wavefront shape reconstruction
PublicationMany of the current studies in the area of damage detection using elastic wave propagation are based on deploying sensor networks with a large number of piezoelectric transducers to detect small-size cracks. A major limitation of these studies is that cracks are usually larger and have different shapes in real cases. Moreover, using a large number of sensing nodes for damage detection is both costly and computationally intensive....
-
Low-energy positron collisions with water: elastic and rotationally inelastic scattering
PublicationDifferential, integral and momentum transfer cross sections for the vibrationally elastic and rotationally inelastic scattering of positrons from water at low collision energy (E ≤ 10 eV) are reported. Several models within the R-matrix method are used to compute the body-fixed T-matrices, while the scattering calculations are performed within the fixed-nuclei approximation corrected with the standard Born-closure formula. These...
-
Prediction of skin color, tanning and freckling from DNA in Polish population: linear regression, random forest and neural network approaches
Publication -
Application of the MSPD Technique for the HPLC Analysis of Rutin in Sambucus nigra L.: The Linear Correlation of the Matrix Solid-Phase Dispersion Process
Publication -
Softly switched robustly feasible mpc for constrained linear systems under set bounded uncertainty- LQ-MPC with IC action
PublicationNie jest możliwe efektywne sterowanie procesem w szerokim zakresie zmian warunków operacyjnych przy użyciu jednego uniwersalnego regulatora. W pracy zaproponowano koncepcję sposobu regulacji polegającego na przełączaniu wielu regulatorów uzależnionego od stanu operacyjnego systemu. Często twarde przełączanie regulatorów nie jest pożądane lub wręcz możliwe, alternatywą jest ich miękkie przełączanie. W pracy rozważany jest problem...
-
Ground anchors diagnostic process based on elastic wave propagation method
PublicationThe paper is focused on analysis of elastic wave propagation in the context of diagnostics of ground anchors. Numerical simulations were performed to assess the possibility of evaluation of the anchorage quality. It was assumed that the quality and the load capacity of the anchor system directly depend on the length, on which mortar and steel cooperate.
-
Solution of coupled integral equations for quantum scattering in the presence of complex potentials
PublicationIn this paper, we present a method to compute solutions of coupled integral equations for quantum scattering problems in the presence of a complex potential. We show how the elastic and absorption cross sections can be obtained from the numerical solution of these equations in the asymptotic region at large radial distances.
-
Dynamic unattended measurement based routing algorithm for diffServ architecture
PublicationDynamic routing is very important in terms of assuring QoS in today's packet networks especially for streaming and elastic services. Existing solutions dedicated to dynamic routing are often too complicated and seem to be not usable in real time traffic scenarios where transferred traffic may vary significantly. This was the main reason for research and new routing mechanism proposal which should apply to today's packet networks....
-
A hyperelastic model for soils with stress-induced and inherent anisotropy
PublicationIn this paper, modelling of the superposition of stress-induced and inherent anisotropy of soil small strain stiffness is8presented in the framework of hyperelasticity. A simple hyperelastic model, capable of reproducing variable stress-induced9anisotropy of stiffness, is extended by replacement of the stress invariant with mixed stress–microstructure invariant to10introduce constant inherent cross-anisotropic component. A convenient...
-
A study on microcrack monitoring in concrete: discrete element method simulations of acoustic emission for non-destructive diagnostics
PublicationThe research is focused on the monitoring of fracture evolution in concrete beams under three-point bending using the acoustic emission technique and the discrete element method. The main objective of the study was to numerically and experimentally investigate the mechanism behind the generation of elastic waves during acoustic emission events and their interaction with micro- and macro-cracking in concrete beams under monotonic...
-
Linear impedance of 35P2O5-30Fe2O3-35Nb2O5
Open Research DataThe electrical properties of phosphate-iron glasses containing niobium were investigated. Glass samples of the composition of 35P2O5-30Fe2O3-35Nb2O5 (in %mol) were prepared by the conventional melt quenching technique. Appropriate amounts of reagents ((NH4)2HPO4 (≥99.9%, POCH), Fe2O3 (≥99.9%, POCH), Nb2O5 (≥99.9%, PLUKA AG) and TiO2 (≥99.9%, anatase...
-
Bending of a Three-Layered Plate with Surface Stresses
PublicationWe discuss here the bending deformations of a three-layered plate taking into account surface and interfacial stresses. The first-order shear deformation plate theory and the Gurtin-Murdoch model of surface stresses will be considered and the formulae for stiffness parameters of the plate are derived. Their dependence on surface elastic moduli will be analyzed.
-
<title>Cavity digital control testing system by Simulink step operation method for TESLA linear accelerator and free electron laser</title>
Publication -
Fixed final time and free final state optimal control problem for fractional dynamic systems – linear quadratic discrete-time case
Publication -
Visualizing the Dose Distribution and Linear Energy Transfer by 1D and 2D ESR Imaging: A Potassium Dithionate Dosimeter Irradiated with C6+ and N7+ Ions
Publication -
Modal Adjustment of Rayleigh Based Structural Damping and Coordinate-Partitioning Algorithm Dedicated to Frictionless Contact Constraints between Multibody System and Structure Modelled with Finite Elements
PublicationThe paper presents a dedicated numerical algorithm. The algorithm is advantageous during investigations of the dynamics of a hybrid multibody / finite-elements system. We focus our attention on interactions resulting from mechanical contact. Pointwise contact connects a vertex of the multibody structure and a surface of the elastic reference body. Instead of a positive value of the relative penetration factor, constraint equations...
-
Simulations of spacing of localized zones in reinforced concrete beams using elastic-plasticity and damage mechanics with non-local softening
PublicationArtykuł omawia obliczanie belek żelbetowych z uwzględnieniem lokalizacji odkształceń. Obliczenia wykonano przy zastosowaniu MES na bazie sprężysto-plastycznego prawa konstytutywnego i modelu zniszczeniowego uwzględniającego degradację sztywności rozszerzonego o długość charakterystyczną mikrostruktury za pomocą teorii nielokalnej.
-
Spectral Finite Element Method in Condition Monitoring and Damage Detection
PublicationIt is well known that the dynamic behaviour of engineering structures may carry very important and crucial information that can be further used for the assessment of their condition as well as detection of any damage induced. The current interest in monitoring techniques based on the propagation of guided elastic waves requires that numerical techniques used for modelling the phenomena associated must shift into the realm of high...
-
Time-of-flight electron scattering from molecular hydrogen: Benchmark cross sections for excitation of the X1Σ+g→b3Σ+u transition
PublicationThe electron impact X1Σ+g to b3Σ+u transition in molecular hydrogen is one of the most important dissociation pathways to forming atomic hydrogen atoms, and is of great importance in modeling astrophysical and industrial plasmas where molecular hydrogen is a substantial constituent. Recently it has been found that the convergent close-coupling (CCC) cross sections of Zammit et al. [Phys. Rev. A 95, 022708 (2017)] are up to a factor...
-
SZACOWANIE ZAWARTOŚCI BENZO(a)PIRENU W PYLE ZAWIESZONYM PM10 W AGLOMERACJI TRÓJMIEJSKIEJ ZA POMOCĄ WIELOWYMIAROWEJ REGRESJI LINIOWEJ=ESTIMATION OF BENZO(A)PYRENE CONTENT IN SUSPENDED DUST PM10 IN TRI-CITY AGGLOMERATION USING MULTIDIMENSIONAL LINEAR REGRESSION
PublicationW pracy przedstawiono próbę oszacowania przy pomocy wielowymiarowej regresji liniowej modelu empirycznego opisującego czynniki wpływające na zawartość B(a)P w pyle zawieszonym PM10 w Aglomeracji Trójmiejskiej w latach 2008-2011. Na przestrzeni tych lat średnioroczne stężenie B(a)P w PM10 wzrosło ponad dwukrotnie i ponad trzykrotnie przewyższa poziom docelowy. Z przeprowadzonych analiz wynika, że główną przyczyną wzrostu stężenia...
-
Modelling of shear localization during granular flow within non-local hypoplasticity using material point method
PublicationArtykuł omawia wyniki numeryczne dotyczące powstawania lokalizacji odkształceń stycznych w materiałach granulowanych Obliczenia wykonano dla ściskania dwuosiowego i przypływu silosowego stosując hipoplastyczny model konstytutywny rozszerzony o długość charakterystyczną w ramach nielokalnej teorii. Zastosowano podejście punktów materialnych w celu uniknięcia nadmiernej deformacji elementów skończonych.
-
An in situ technique for the assessment of adhesive properties of a joint under load
PublicationSlow crack propagation in adhesive bonded joints has been characterised using an asymmetric wedge test. Crack position was evaluated from strain gauge measurements, both in the debonded partof the joint and in the bonded zone. Test temperature was changed during loading, giving insight into bond evolution. The technique allows accurate, and virtually continuous, determination of crack position to be made, and therefore the evaluation...
-
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...
-
Anti-plane shear waves in an elastic strip rigidly attached to an elastic half-space
PublicationWe consider the anti-plane shear waves in a domain consisting of an infinite layer with a thin coating lying on an elastic half-space. The elastic properties of the coating, layer, and half-space are assumed to be different. On the free upper surface we assume the compatibility condition within the Gurtin–Murdoch surface elasticity, whereas at the plane interface we consider perfect contact. For this problem there exist two possible...
-
The effective elastic properties of human trabecular bone may be approximated using micro-finite element analyses of embedded volume elements.
PublicationBoundary conditions (BCs) and sample size affect the measured elastic properties of cancellous bone. Samples too small to be representative appear stiffer under kinematic uniform BCs (KUBCs) than under periodicity-compatible mixed uniform BCs (PMUBCs). To avoid those effects, we propose to determine the effective properties of trabecular bone using an embedded configuration. Cubic samples of various sizes (2.63, 5.29, 7.96, 10.58...
-
Bifurcation of equilibrium forms of an elastic rod on a two-parameter Winkler foundation
PublicationWe consider two-parameter bifurcation of equilibrium states of an elastic rod on a deformable foundation. Our main theorem shows that bifurcation occurs if and only if the linearization of our problem has nontrivial solutions. In fact our proof, based on the concept of the Brouwer degree, gives more, namely that from each bifurcation point there branches off a continuum of solutions.
-
Transverse surface waves on a cylindrical surface with coating
PublicationWe discuss the propagation of transverse surface waves that are so-called whispering-gallery waves along a surface of an elastic cylinder with coating. The coating is modelled in the framework of linearized Gurtin–Murdoch surface elasticity. Other interpretations of the surface shear modulus are given and relations to so-called stiff interface and stiff skin model are discussed. The dispersion relations are obtained and analyzed.
-
Linear impedance of 35P2O5-30Fe2O3-20Nb2O5-15TiO2
Open Research DataThe electrical properties of phosphate-iron glasses containing niobium and titanium were investigated. Glass samples of the composition of 35P2O5-30Fe2O3-20Nb2O5-15TiO2 (in %mol) were prepared by the conventional melt quenching technique. Appropriate amounts of reagents ((NH4)2HPO4 (≥99.9%, POCH), Fe2O3 (≥99.9%, POCH), Nb2O5 (≥99.9%, PLUKA AG) and TiO2...
-
Linear impedance of 35P2O5-30Fe2O3-27.5Nb2O5-7.5TiO2
Open Research DataThe electrical properties of phosphate-iron glasses containing niobium and titanium were investigated. Glass samples of the composition of 35P2O5-30Fe2O3-27.5Nb2O5-7.5TiO2 (in %mol) were prepared by the conventional melt quenching technique. Appropriate amounts of reagents ((NH4)2HPO4 (≥99.9%, POCH), Fe2O3 (≥99.9%, POCH), Nb2O5 (≥99.9%, PLUKA AG) and...
-
Elastic distortional buckling of thin-walled bars of closed quadratic cross-section
PublicationIn this study a tin-walled bar with closed quadratic cross-section is considered. The elastic stability of axially compressed bar related to the cross-section distortion is investigated. The governing differential equatio is derived with aid of the principle of stationary potential energy. The critical load for simply supported bar is found in an analytical form and it is copared with the FEM solution. Sufficient accuracy of the...
-
Elastic distortional buckling of thin-walled bars of closed quadratic cross-section
PublicationIn this study a thin-walled bar with closed quadratic cross-section is considered. The elastic stability of axially compressed bar related to the cross-section distortion is investigated. The governing differential equation is derived with aid of the principle of stationary total potential energy. The critical load for the simply supported bar is found in analytical form and it is compared with the FEM solution. Sufficient accuracy...
-
Generalized Taylor formula and shell structures for the analysis of the interaction between geosythetics and engineering structures of transportation lines
PublicationThe analysis of the interaction between geosynthetics and engineering structures (e.g. railroad bed, soil foundation, pipeline) assumes that the geosynthetic form elastic membranes or shell laid on different types of foundations. The mathematical description of that problems in continuous domain employs Laplace operator Δ or d’Alembert operator □. In this paper we demonstrate the analysis based on generalize Taylor formula, and...
-
Theoretical and experimental study on scattering of low-energy electrons by dimethyl and diethyl ethers
PublicationWe report a joint theoretical and experimental investigation on low-energy electron scattering by dimethyl and diethyl ethers. The experimental elastic differential cross sections were measured at impact energies from 1 eV up to 30 eV and scattering angle range of 10◦ to 130◦. Theoretical elastic differential, integral and momentum-transfer cross sections are calculated at impact energies up to 30 eV, employing the Schwinger multichannel...
-
Distortional buckling of thin-walled columns of closed quadratic cross-section
PublicationThe elastic stability of axially compressed column related to the cross-section distortion is investigated. Two kinds of closed quadratic cross-sections are taken into consideration with internal walls and without it. The governing differential equation is derived with aid of the principle of stationary total potential energy. The critical loads for the simply supported columns are found in an analytical form and compared with...
-
Jacek Chróścielewski prof. dr hab. inż.
People -
SIMULATION OF PROCEED® SURGICAL MESH APPLIED TO VENTRAL HERNIA REPAIR
PublicationIn the present research, Proceed® implant is considered. The system is subjected to short-time dynamic pressure load, similar to post-operative cough naturally occurring in human abdomen. The model refers to a clinical case of 5cm of hernia operated by Proceed implant fixed by 15 joints every 3cm around the orifice. The simulations of the implanted mesh are performed by means of the Finite Element Method. The implant is modelled...