<abstract xmlns="http://www.w3.org/1999/xhtml"> In this contribution a new phenomenological model for pressure loaded foam materials is proposed. The presented relationship between compressive stresses and compressive strains is derived by using simple rheological models. The proposed model contains several parameters. The procedure of their identification and the influence of parameters on a curve shape are also explained. The accuracy of our model is tested and compared with other phenomenological models. These tests have been applied on aluminium and polyurethane foams.</abstract>

Faculty of Electrical Engineering and Information Technology, Slovak University of Technology in Bratislava, Department of Mechanics, Ilkovičova 3, 812 19 Bratislava, Slovakia

Faculty of Mechanical Engineering, Slovak University of Technology in Bratislava,Institute of Applied Mechanics and Mechatronics, Nám. Slobody 17,812 31 Bratislava, Slovakia

Phenomenological Material Model of Foam Solids

VŠB-Technical University of Ostrava, Department of Applied Mechanics, Faculty of Mechanical Engineering, Centre of Excellence IT4Innovations, 17.listopadu 15, Ostrava, Czech Republic

VŠB-Technical University of Ostrava, Department of Applied Mechanics, Faculty of Mechanical Engineering, Centre of Excellence IT4Innovations, 17.listopadu 15, Ostrava, Czech Republic;

VŠB-Technical University of Ostrava, Department of Applied Mechanics, Faculty of Mechanical Engineering, 17.listopadu 15, Ostrava, Czech Republic;

Bonatrans Group, Bohumín, Revoluční 1234, 735 94, Czech Republic;

Cyclic Plastic Properties of Class C Steel Emphasizing on Ratcheting: Testing and Modelling

<abstract xmlns="http://www.w3.org/1999/xhtml"> In this contribution, results of elastostatic analysis of spatial composite beam structures are presented using our new beam finite element of double symmetric cross-section made of a Functionally Graded Material (FGM). Material properties of the real beams vary continuously in the longitudinal direction while variation with respect to the transversal and lateral directions is assumed to be symmetric in a continuous or discontinuous manner. Continuously longitudinal varying spatial Winkler elastic foundations (except the torsional foundation) and the effect of axial and shear forces are considered as well. Homogenization of spatially varying material properties to effective quantities with a longitudinal variation is done by the multilayer method (MLM). For the homogenized beam finite element the local stiffness matrix is established by means of the transfer matrix method. By the conventional finite element procedure, the global element stiffness matrix and the global system of equation for the beam structure are established for calculation of the global displacement vector. The secondary variables (internal forces and moments) are then calculated by means of the transfer relations on the real beams. Further, the mechanical stress in the real beams are calculated. Finally, the numerical experiments are carried out concerning the elastic-static analysis of the single FGM beams and beam structures in order to show the possibilities of our approach.</abstract>

Slovak University of Technology in Bratislava, Faculty of Electrical Engineering and Information Technology, Ilkovicova 3, 812 19 Bratislava, Slovakia

Institute for Mechanics of Materials and Structures, Karlsplatz 13, A-1040 Vienna, Austria

Elastostatic Analysis of the Spatial FGM Structures

<abstract xmlns="http://www.w3.org/1999/xhtml"> The finite element method (FEM) is developed for coupled thermoelastic crack problems if material properties are continuously varying. The weak form is utilized to derive the FEM equations. In conventional fracture theories the state of stress and strain at the crack tip vicinity is characterized by a single fracture parameter, namely the stress intensity factor or its equivalent, J-integral. In the present paper it is considered also the second fracture parameter called as the T-stress. For evaluation of both fracture parameters the quarter-point crack tip element is developed. Simple formulas for both fracture parameters are derived comparing the variation of displacements in the quarter-point element with asymptotic expression of displacement at the crack tip vicinity. The leading terms of the asymptotic expansions of fields in the crack-tip vicinity in a functionally graded material (FGM) are the same as in a homogeneous one with material coefficients taken at the crack tip.</abstract>

Institute of Construction and Architecture, Slovak Academy of Sciences, 845 03 Bratislava, Slovakia,

Institute of Construction and Architecture, Slovak Academy of Sciences, 845 03 Bratislava, Slovakia

Evaluation of Fracture Parameters for Cracks in Coupled Thermoelasticity for Functionally Graded Materials

<abstract xmlns="http://www.w3.org/1999/xhtml"> In this paper, a meshless local Petrov-Galerkin (MLPG) method is proposed to calculate mechanical and electrical responses of three-dimensional piezoelectric semiconductors under static load. The analyzed solid is discretized by a set of generally distributed nodal points distributed over 3D geometry. Local integral equations (LIEs) are derived from the weak form of governing equations over small local subdomains. The subdomains have a spherical shape with a nodal point located in its centre. A unit step function is used as the test functions in the local weak-form. The moving least-squares (MLS) method is adopted for the approximation of the physical quantities in the LIEs. The proposed MLPG method is verified by using the corresponding results obtained with the finite element method. Numerical examples are presented and discussed for various boundary conditions and loading scenarios to show the performance of the developed MLPG method for analysis piezoelectric semiconducting solids.</abstract>

Institute of Construction and Architecture, Slovak Academy of Sciences, Dúbravská cesta 9, 845 03 Bratislava, Slovak Republic

Institute of Construction and Architecture, Slovak Academy of Sciences, Dúbravská cesta 9, 845 03 Bratislava, Slovak Republic;

Analysis of Piezoelectric Semiconducting Solids by Meshless Method

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Strojnícky časopis - Journal of Mechanical Engineering

 The Strojnícky časopis – Journal of Mechanical Engineering publishesoriginal scientific and application oriented papers, dealing withproblems of modern technologies in the fields of mechanicalengineering including:   structural and solid mechanics,  fluid mechanics,  mechatronics,  multi-physical problems,  biomedical engineering,  advanced micro and nano materials,  structural and machine design,  virtual and rapid protyping,  power and process engineering,  strength of materials, creep, plasticity,  fracture mechanics and fatigue,  durability and reliability of engineering structures,  production engineering, etc.   This considers the following activities in mechanical engineering andcross-linked branches as modelling, simulations, experiment,construction, testing, measuring, operation, production, environmentalaspects, quality, etc.  The Strojnícky časopis – Journal of Mechanical Engineering publishesthe following types of papers:   Regular Articles should describe original research of highquality or new application in the field of Mechanical Engineering.  Review Articles will generally be specially commissioned,however, suggestions for topics and authors are welcomed by theEditor-in-Chief.  Technical Notes provide rapid publication of important newcontributions.   Please see our Guide for Authors for information on articlesubmission. If you require any further information or help, please donot hesitate to contact us.  The submitted papers are peer-reviewed and tested against plagiarism.  The journal does not have article processing charges (APCs) norarticle submission charges.  Archiving  Sciendo archives the contents of this journal in Portico - digital long-term preservation service of scholarly books, journals and collections.  Plagiarism Policy  The editorial board is participating in a growing community of Similarity Check System's users in order to ensure that the content published is original and trustworthy. Similarity Check is a medium that allows for comprehensive manuscripts screening, aimed to eliminate plagiarism and provide a high standard and quality peer-review process. 