JOURNAL OF THEORETICAL AND APPLIED MECHANICS

JOURNAL OF THEORETICAL AND APPLIED MECHANICS

 

 

No. 2, Vol  44, 2006

 

Zmitrowicz A. - Wear patterns and laws of wear - a review (219-253) azmit@imp.gda.pl

 

Abstract. Wear is a process of gradual removal of a material from surfaces of solids subject to contact and sliding. Damages of contact surfaces are results of wear. They can have various patterns (abrasion, fatigue, ploughing, corrugation, erosion and cavitation). The results of abrasive wear are identified as irreversible changes in body contours and as evolutions of gaps between contacting solids. The wear depth profile of a surface is a useful measure of the removed material. The definition of the gap between contacting bodies takes into account deformations of bodies and evolutions of wear profiles. The wear depth can be estimated with the aid of wear laws. Derived in this study, constitutive equations of anisotropic wear are extensions of the Archard law of wear. The equations describe abrasion of materials with microstructures. The illustrative example demonstrates calculations of the abraded mass and temperatures in pin-on-disc test rig.

Key words: contact mechanics, wear, friction, constitutive equations

 

 

Żardecki D. - Piecewise linear modeling of friction and stick-slip phenomenon in discrete dynamical systems (255-277) zardecki@pimot.org.pl

 

Abstract. The paper presents an idea and application of a new method of the modeling of mechanical systems with friction. This method is based on the piecewise linear luz(...) and tar(...) projections and their original mathematical apparatus. The presented models of systems with friction describe the stick-slip phenomenon in detail.

Key words: piecewise linear projections, mathematical modeling, friction, stick-slip

 

 

Tomski L., Szmidla J. - Free vibrations of a column loaded by a stretched element (279-298) szmidla@imipkm.pcz.pl

 

Abstract. The problem of free vibrations of a two-member column loaded by a sretched element is considered in the paper. The influence of rigidity asymmetry on the bending between the stretched element and column rods, and the influence of the rigid mounting of the loading element and its length on the course of natural frequency in relation to the external load are analysed. The regions, for which the tested systems appear to be of divergence or divergence-pseudo-flutter type, are determined for presented physical and geometrical parameters of the column and systems for border values of the coefficient of bending asymmetry. Numerical computations are supported by appropriate results of experimental investigations.

Key words: elastic column, divergence instability, pseudo flutter systems, natural frequency

 

 

Pawlus D. - Solution to the static stability problem of three-layered annular plates with a soft core (299-322) doro@ath.bielsko.pl

 

Abstract. The solutions to the static stability problem of a three-layered annular plate with a soft core and a symmetric cross-section structure are presented in this paper. The basic element of the solution is the formulation of a system of differential equations describing plate deflections and the use of the finite difference method in calculation of critical loads of buckling forms solving the eigen-value problem. The solution indicates the minimal values of static critical loads as well as the buckling forms of plates compressed on a selected edge. The obtained results have been compared with those obtained for plate models built by means of the finite element method. The final remarks concerning the forms of the loss of static stability of analysed plates with the sandwich structure have been formulated. This paper is a complement of the work by Pawlus (2005), which concerned calculations of the dynamic stability of plates, and it is an extension to cases of wave forms of the plate buckling problem earlier presented only for regular, axially-symmetrical forms of deformation in, eg., Pawlus (2002).

Key words: sandwich, annular plate; static stability; buckling form; finite differences method; FEM

 

 

Bojczuk D., Szteleblak W. - Application of finite variations to topology and shape optimization of 2D structures (323-349) mecdb@eden.tu.kielce.pl; szteleblak@go2.pl

 

Abstract. The method of simultaneous topology and shape optimization of 2D structures by finite topology modification is presented in the paper. Both, structures in a plane state of stress and bending Kirchhoff's plates are analyzed here. Conditions for the introduction of finite topology modification based on the topological derivative are specified. When the respective condition is satisfied, finite holes and finite variations of existing boundaries are introduced into the structure. Next, standard shape optimization of new holes and variable boundaries is performed. Two basic types of modification are considered here, namely the introduction of holes of a prescribed size and shape and the introduction of holes of an unknown size and shape together with the introduction of finite changes of other boundaries. A heuristic algorithm for optimal design of topology and shape is proposed in the paper. Illustrative examples confirm applicability of the proposed approach.

Key words: 2D structures, optimal topology and shape, topological derivative, finite modification, structure evolution

 

 

Burczyński T., Długosz A., Kuœ W. - Parallel evolutionary algorithms in shape optimization of heat radiators (351-366) Tadeusz.Burczynski@polsl.pl;

Adam.Dlugosz@polsl.pl; Waclaw.Kus@polsl.p

Abstract. The paper deals with the application of Parallel Evolutionary Algorithms (PEA) and the Finite Element Method (FEM) in shape optimization of heat radiators. The fitness function is computed with the use of the coupled thermoelsticity modelled by MARC/MENTAT software. The geometry, mesh and boundary conditions are created on the basis of a script language implemented in MENTAT. In order to reduce the number of design parameters in evolutionary algorithms, the shape of the structure is modelled by Bezier curves. Numerical examples for some shape optimization are included.

Key words: coupled thermoelasticity, radiation, finite element method, parallel evolutionary algorithm, evolutionary optimization, shape optimization

 

Mochnacki B., Suchy J.S. - Simplified models of macrosegregation (367-379)

moch@imi.pcz.pl; jsuchy@agh.edu.pl

 

Abstract. The macrosegregation process takes place during typical solidification of alloys. Fractions of alloy components in a liquid and solid sub-domains are time-dependent and determined by the course of border lines on the equilibrium diagram. From the mathematical point of view, the process is described by a system of partial differential equations (diffusion equations) and boundary-initial conditions. The process is coupled with the solidification one. In this paper, simplified models of macrosegregation are discussed. The volumetric solidification and the 'sharp' solid-liquid interface are considered. Examples of computations are also shown. It seems that for practical applications, the methods proposed are sufficiently exact. Additionally, they are very simple for numerical realization.

Key words: macrosegregation, solidification, numerical simulation

 

 

Majchrzak E., Kałuża G. - Sensitivity analysis of biological tissue freezing process with respect to the radius of spherical cryoprobe (381-392) ewa.majchrzak@polsl.pl; grazyna.kaluza@polsl.pl

 

Abstract. Application of the shape sensitivity analysis to the case of problems of the biological tissue freezing process is discussed. The freezing process described by a strongly non-linear bioheat transfer equation in which an additional term controlling the evolution of latent heat appears. Using the approach called 'the one domain method', one finally obtains a partial differential equation containing the substitute thermal capacity of tissue. The boundary and initial conditions determine the thermal interaction between the tissue and cryoprobe tip.

In the paper, we consider a spherical internal cryoprobe. In order to estimate the influence of cryoprobe geometry on the course of the process, the shape sensitivity analysis is applied. In particular, a direct approach is used (explicit differentiation method). The results of numerical modeling (the boundary element method is applied) allow one to formulate essential practical conclusions concerning the course of cryosurgery treatments.

Key words: freezing process, sensitivity analysis, boundary element method

 

 

Ciesielski M., Leszczynski J. - Numerical solutions to boundary value problem for anomalous diffusion equation with Riesz-Feller fractional operator (393-403)

mariusz@imi.pcz.pl; jale@imi.pcz.pl

Abstract. In this paper, we present a numerical solution to an ordinary differential equation of a fractional order in one-dimensional space. The solution to this equation can describe a steady state of the process of anomalous diffusion. The process arises from interactions within complex and non-homogeneous background. We present a numerical method which is based on the finite differences method. We consider a boundary value problem (Dirichlet conditions) for an equation with the Riesz-Feller fractional derivative. In the final part of this paper, some simulation results are shown. We present an example of non-linear temperature profiles in nanotubes which can be approximated by a solution to the fractional differential equation.

Key words: Riesz-Feller fractional derivative, boundary value problem, Dirichlet conditions, finite difference method

Tuliszka-Sznitko E., Zieliński A. - Numerical investigation of transitional flow in co- and counter-rotating annular cavity (405-420) sznitko@sol.put.poznan.pl

Abstract. A 3D direct numerical simulation is performed to study the transitional flow in co- and counter-rotating annular cavity of the aspect ratio~5. The identification and characterization of mechanisms related to the laminar-turbulent process in rotating cavities should improve the prediction methods and lead to new, more effective boundary layer control strategies. Numerical computations are based on the pseudo-spectral Chebyshev-Fourier method for solving the incompressible Navier-Stokes equation. The numerical computations allow one to describe the steady axisymmetric basic state and 3D instability structures which appear in the transitional flow. The DNS computations are interpreted in the light of our LSA results. Moreover, the absolute instability regions are theoretically identified and the critical Reynolds numbers of the convective/absolute transition in both layers are given.

Key words: laminar-turbulent transition, rotating cavity, direct method

 

 

Biuletyn Informacyjny PTMTS (421-447)

 

 

 

No. 1, Vol  44, 2006

 

Baron E. - On modelling of periodic plates with inhomogeneity period of an order of the plate thickness (3-18) eugeniusz.baron@polsl.pl

 

Gałkiewicz J., Graba M. - Algorithm for determination of , , , ,  functions in Hutchinson Rice Rosengren solution and its 3D generalization (19-30) jgalka@eden.tu.kielce.pl; mgraba@eden.tu.kielce.pl

 

Goszczyński J.A. - Practical aspects of identification of the aerodynamic characteristics (31-50) jaglot@poczta.onet.pl

Juraszek J. - The clamped joints  - survey and analysis of shapes and materials (51-73) juraszek@ath.bielsko.pl

 

Kubiak T. - Interactive buckling in thin-walled beam-columns with widthwise varying orthotropy (75-90) tomek@p.lodz.pl

Majkut L. - Identification of beam boundary conditions in ill-posed problem (91-105) majkut@agh.edu.pl

Piechnik S. - Algebra of systems of forces applied to the flat material line (107-125)

sp@limba.wil.pk.edu.pl

 

Rozumek D., Macha E., Lazzarin P., Meneghetti G. - Influence of notch (TIP) radius on fatigue crack growth rate (127-137) drozumek@po.opole.pl; emac@po.opole.pl; plazzarin@gest.unipd.it; meneghetti@unipd.it

Wojnarowski J., Kopeć J., Zawiœlak S. - Gears and graphs (139-162)

szawislak@ath.bielsko.pl

Żardecki D. - Piecewise linear luz(...) and tar(...) projections. Part~1 - Theoretical background (163-184) zardecki@pimot.org.pl

Żardecki D. - Piecewise linear luz(...) and tar(...) projections. Part~2 - Application in modelling of dynamic systems with freeplay and friction (185-202) zardecki@pimot.org.pl

Biuletyn Informacyjny PTMTS (203-213)

No. 4, Vol  43, 2005

 

 

Rozumek D. - Fatigue crack growth rate in aluminium alloy including Mixed Mode I and III (731-743) drozumek@po.opole.pl

 

Dyka E., Rogowski B. - On the contact problem for a smooth punch in piezoelectroelasticity (745-761) edyka@p.lodz.pl, brogowsk@p.lodz.pl

 

Domoradzki M., Jaroszewicz J., Zoryj L. - Analysis of the influence of elasticity constants and material density on the base frequency of axi-symmetrical vibrations with variable thickness plates (763-775) jerzyj@pb.bialystok.pl

 

Major M. - Velocity of acceleration wave propagating in hyperelastic Zahorski and Mooney-Rivlin materials (777-787) admin@major.strefa.pl

 

Matysiak S.J. - On homogenized model of periodic stratified micropolar elastic composites (789-804) s.j.matysiak@uw.edu.pl

 

Wojnar R. - Structural control in tissue development (805-812) rwojnar@ippt.gov.pl

 

Blajer W., Czaplicki A. - An alternative scheme for determination of joint reaction forces in human multibody models (813-824) wblajer@poczta.onet.pl, czaplicki@poczta.onet.pl

 

Rudnicki M. - On the material and spatial description of rigid fields (825-840) marr@siwy.il.pw.edu.pl

 

Garus J. - A method of determination of feasible propeller forces and moments for an underwater robot (841-853) j.garus@amw.gdynia.pl

 

Żyluk A. - Experimental validation of mathematical model describing external stores separation (855-873) andrzej.zyluk@itwl.pl

 

Skup Z. - Damping of vibrations in a power transmission system containing a friction clutch (875-892) zskup@ipbm.simr.pw.edu.pl

 

Juraszek J. - Strength analysis of a multi-clip joint (893-907) jjuraszek@ath.bielsko.pl

 

Biuletyn Informacyjny PTMTS (909-922)

 

 

 

No. 3, Vol  43, 2005

 

Gabbert U., Nestorović-Trajkov T., Köppe H. - Controller design and implementation for active vibration suppression of a piezoelectric smart shell structure (487-500)

 ulrich.gabbert@mb.uni-magdeburg.de; tamara.nestorovic@mb.uni-magdeburg.de;

 heinz.koeppe@mb.uni-magdeburg.de

 

Giergiel M., Giergiel J. - Advanced modelling of vibratory machines (501-509) giergiel@agh.edu.pl

 

Giergiel J., żylski W. - Description of motion of a mobile robot by Maggie's equations (511-521) jgiergiel@chello.pl; wzylski@prz.edu.pl

 

Hołobut P. - Time-optimal control of hydraulic manipulators with path constraints (523-538) pholob@ippt.gov.pl

 

Klamka J. - Approximate constrained controllability of mechanical system (539-554)

jklamka@ia.polsl.gliwice.pl

 

Lekszycki T. - Functional adaptation of bone as an optimal control problem (555-574)

tlekszyc@ippt.gov.pl

 

Lückel J., Münch E., Vöcking H., Hestermeyer T. - Online optimization of a preview controller - - structure and algorithms (575-591) Joachim.Lueckel@mlap.de;

muench@mlap.de; Henner.Voecking@mlap.de; Thorsten.Hestermeyer@mlap.de

 

Müller P.C. - Modelling and control of mechatronic systems by the descriptor approach (593-607) mueller@srm.uni-wuppertal.de

 

Przybyłowicz P.M. - Stability of actively controlled rotating shaft made of functionally graded material (609-630) piotrp@ipbm.simr.pw.edu.pl

 

Sapiński B. - Real-time control for a magnetorheological shock absorber in a driver seat (631-653) deep@agh.edu.pl

 

Sapiński B., Martynowicz P. - Vibration control in a pitch-plane suspension model with MR shock absorbers (655-674) deep@agh.edu.pl; pmartyn@agh.edu.pl

 

Socha L. - Application of poli-criterial linearization for control problem of stochastic dynamic systems (675-693) leslawsocha@poczta.onet.pl

 

Tylikowski A. - Stabilization of plate parametric vibration via distributed control (695-706) aty@simr.pw.edu.pl

 

Biuletyn Informacyjny PTMTS (707-726)