Weakened Zones in Wood – Based Composite Beams and Their Strengthening by CFRP: Experimental, Theoretical, and Numerical AnalysisKrzysztof KULA, Tomasz SOCHA & Arkadiusz DENISIEWICZ
This paper looks at the mechanical behaviour of wood-based beams. Laboratory tests of an I-beam show a considerable decrease of capacity in the weakened zones, e.g., at the connection between two pieces of pine wood used as a flange. We propose strengthening of the zones using fibre composite tapes based on CFRP. This article demonstrates the way for protection of the I-beam with defects in the bottom flange against the loss of load-carrying capacity. The...
The paper deals with a proposition of obtaining an analytical solution for a beam on elastic foundation. The main objective of presented work was stability analysis of the axially compressed beam. The analytical model was proposed. Shape function for inhomogeneous properties of the foundation was assumed. The Galerkin method was used to calculate the values of critical forces. Main conditions have been defined. The critical loads as a function of geometric and mechanical properties of...
Study of the Distribution of Normal Contact Pressure Between Parts Joined in a Multi-Bolted System under Operational LoadsRafał GRZEJDA
Modelling and calculations of unsymmetrical multi-bolted connections treated as a system for different bolt models and contact layer models between the joined parts are presented. The modelling refers to preloaded and externally loaded connections. The systemic models of the connection for two substitute models of bolts are shown. Between the joined parts two types of the Winkler model of a contact layer are taken into consideration. Calculations were made for an exemplary unsymmetrical connection. Its...
Three-phase parabolic inhomogeneities with internal uniform stresses in plane and anti-plane elasticityX. Wang & P. Schiavone
We examine the in-plane and anti-plane stress states inside a parabolic inhomogeneity which is bonded to an infinite matrix through an intermediate coating. The interfaces of the three-phase parabolic inhomogeneity are two confocal parabolas. The corresponding boundary value problems are studied in the physical plane rather than in the image plane. A simple condition is found that ensures that the internal stress state inside the parabolic inhomogeneity is uniform and hydrostatic. Furthermore, this condition is...
Use of the higher-order plate theory of I. N. Vekua type in problems of dynamics of heterogeneous plane waveguidesO.V. Egorova, L.N. Rabinskiy & S.I. Zhavoronok
The dynamics of elastic plane waveguides is studied on the basis of the extended formulation of the plate theory of N^th order. The plate model is based on the Lagrangian formalism of analytical dynamics combined with the dimensional reduction approach and the biorthogonal expansion of the spatial distribution of the displacement. The boundary conditions shifted from the faces onto the base plane are interpreted as constraints for the variational formulation of two-dimensional plate models. The...
This paper has the goal of defining a class of uncertain structural systems for which it is possible to consider an approach able to give the exact response in terms of the probability density function (PDF). The uncertain structures have been identified in the discretized statically determined ones and the approach has been identified in the coupling of the approximated principal deformation modes method (APDM) and of the probability transformation method (PTM). The first one...
A mixed finite element formulation is developed for the general 2D plane strain, linear isotropic gradient elasticity problem. Form II of the dipolar strain gradient theory for micro-structured solids is considered. The main variables are the double stress tensor μ and the displacement field vector u. Standard C0−continuous, high polynomial order hierarchical basis functions are employed for the finite element solution spaces (p-extension). The formulation is numerically validated against the standard axial tension patch test...
Thermal buckling and free vibration of Euler–Bernoulli FG nanobeams based on the higher-order nonlocal straingradient theoryG. JANEVSKI, N. DESPENIĆ & I. PAVLOVIĆ
A size-dependent Euler–Bernoulli beam modelis derived within the framework of the higher-order nonlocal strain gradient theory. Nonlocal equations of motion are derived by applying Hamilton’s principle and solved withan analytical solution. The solution is obtained using the Navier solution procedure. In the case of simply supported boundary conditions, the analytical solutions of natural frequencies and critical buckling temperature for free vibration problems are obtained. The paper investigates the thermal effects on buckling and free vibrational...
Fast GPU simulation of reinforced concrete at the scale of reinforcement ribs by the discrete element methodB. Berisha, S. Hirsiger, H. Hippke, P. Hora, A. Mariaux, D. Leyvraz & C. Bezençon
Modeling of anisotropic behavior as well as hardening behavior based on micromechanical quantities in combination with a spectral solver is the focus of this study. A deep drawing steel as well as two different aluminum alloys are investigated. Prediction capabilities of the proposed modeling strategy are discussed and the benefits of the micromechanical model are highlighted. Further, a comparison of the crystal plasticity (CP) results with the well established macroscopic model YLD2000-2d underlines the importance...
Nanofluid flow and heat transfer of carbon nanotube and graphene platelette nanofluids in entrance region of microchannelsM.E. Fuller & J.T.C. Liu
Suspensions of nano-scale particles in liquids, dubbed nanofluids, are of great interest for heat transfer applications. Nanofluids potentially offer superior thermal conductivity to alternative, pure fluids and are of particular interest in applications where active cooling of power-dense systems is required. In this work, the thermophysical properties of carbon nanotube nanofluids (CNTNf) and those of graphene nanoplatelette nanofluids (GNPNf) as functions of particle volume fraction are deduced from published experiments. These properties are applied to...
This paper presents a methodology for the mechanical characterization of agarose millimetric spheres using resonant principles. Detection of the modes of vibration was conducted using a low-cost experimental setup based on an electret microphone adapted with a thin latex elastic membrane for the sensing stage and a piezoelectric actuator driven by a conventional transformer for the excitation stage. The identification of vibration modes is supported through an ANSYS Finite Element model of the experimental setup....
Multi-Scale Numerical Analysis of the Effect of Microstructural Features on the Mechanical Behavior of Polycrystalline Ti-6Al-4V AlloyFatna BENMESSAOUD, Vincent VELAY, Mohammed CHEIKH, Vanessa VIDAL, Christine BOHER & Farhad RÉZAÏ-ARIA
The present work aims to model the influence of microstructural features of Ti-6Al-4V titanium alloy on its mechanical behavior. A multi-scale approach based on crystal plasticity is considered. The elasto-viscoplastic constitutive equations of Meric-Cailletaud are modified to take into consideration the effect of the grain size by introducing the Hall-Petch relationship at the local scale. This modified model is coupled with finite element calculations under small strain assumption to simulate the monotonic mechanical behavior of...
Analytical and Numerical Studies of an Unsymmetrical Sandwich Beam – Bending, Buckling and Free VibrationKrzysztof MAGNUCKI, Ewa MAGNUCKA-BLANDZI, Jerzy LEWIŃSKI & Szymon MILECKI
The subject of the paper is an unsymmetrical sandwich beam. The thicknesses and mechanical properties of the beam faces are different. Mathematical model of the beam is formulated based on the classical broken-line hypothesis. The equations of motions of the beam is derived on the ground of the Hamilton’s principle. Bending, buckling and free-vibration are studied in detail for exemplary unsymmetrical structure of the beam. The values of deflection, critical force and natural frequency are...
Poznań University of Technology6
Phetchabun Rajabhat University2
AGH University of Science and Technology2
Cracow University of Technology2
Vellore Institute of Technology University2
Silesian University of Technology2
An-Najah National University1
Gdańsk University of Technology1