Justín Murín

3D-beam element with continuous variation of the cross-sectional area

Abstract This paper presents the exact stiffness matrix of 3D-beam element with a class of continuously varying cross-sectional properties, which is derived using direct stiffness method and transfer functions of the beam. A nodal load vector for continuously distributed beam loading is also described using transfer functions. All the transfer functions, which occur in the stiffness matrix and nodal load vector, are evaluated numerically. Results of numerical experiments show that this new element satisfies all the relevant equations.

Computational modelling and advanced simulations

Introduction 1. Nonlinear Dynamic Analysis of Partially Supported Beam-Columns on Nonlinear Elastic Foundation Including Shear Deformation Effect, by E.J. Sapountzakis, A.E. Kampitsis 2. Mechanics of viscoelastic plates made of FGMs, by H. Altenbach, V.A. Eremeyev 3. Indirect Trefftz method for solving Cauchy problem of linear piezoelectricity, by G. Dziatkiewicz, P. Fedelinski 4. New Phenomenological Model for Solid Foams, by V. Goga 5. The Effect of an Interphase on Micro-Crack Behaviour in Polymer Composites, by P. Hutar, L. Nahlik, Z. Majer, Z. Knesl 6. Temperature Fields in Short Fibre Composites, by V. Kompis, Z. Murcinkova, M. Ockay 7. Simulation of Distributed Detection of Ammonia Gas, by O. Sykora, J. Aubrecht, R. Klepacek, L. Kalvoda 8. Exact Solution of Bending Free Vibration Problem of the FGM Beams with Effect of Axial Force, by J. Murin, M. Aminbaghai, V. Kutis 9. Wavelet Analysis of the Shear Stress in Soil Layer Caused by Dynamic Excitation A. Borowiec 10. Strength of Composites with Short Fibres, by E. Kormanikova, D. Riecky, M. zmindak 11. A direct boundary element formulation for the first plane problem in the dual system of micropolar elasticity, by Gy. Szeidl, J. Dudra 12. Implementation of meshless method for a problem of a plate large deflection, by A. Uscilowska 13. Modelling and Spatial Discretization in Depletion Calculations of the Fast Reactor Cell with HELIOS 1.10, by R. Zajac, P. Darilek, V. Necas 14. Linear Algebra Issues in a Family of Advanced Hybrid Finite Elements, by N.A. Dumont, C.A. Aguilar Maron 15. On Drilling Degrees of Freedom, by S. Kugler, P.A. Fotiu, Justin Murin 16. Hybrid System for Optimal Design of Mechanical Properties of Composites, by J. Wisniewski, K. Dems 17. Analysis of Representative Volume Elements with Random Microcracks, by P. Fedelinski 18. Application of general boundary element method for numerical solution of bioheat transfer equation, by E. Majchrzak.

The formulation of a new non-linear stiffness matrix of a finite element

This paper presents a new nonlinear stiffness matrix of a finite element without making any simplifications. This matrix inserts the quadratic and cubic dependences of the unknown increments of generalized displacements of nodes into the initially linearized system of equations. For a bar element, the exact form of the matrix is defined and for illustrative one-dimensional problems of pure tension the full system of non-linear equations is given, which is solved by the method described in [M. J. D. Powel, Hybrid Method for Non-linear Equations. McGraw-Hill (1970)]. The calculation is evaluated as far as its convergence is concerned, and the results are compared with those of a classical approach to geometrically non-linear problems represented by the method of finite elements. Thanks to the development of numerical methods of solving the systems of non-linear equations, the new non-linear stiffness matrix can contribute significantly to a more efficient solution of non-linear problems in the mechanics of elastic bodies.

Advances in Quadrilateral Shell Elements with Drilling Degrees of Freedom

A unique derivation of quadrilateral shell elements with six degrees of freedom at each node is presented. The theoretical and numerical formulation is based on the combination of a membrane element with drilling degrees of freedom and a shear deformable plate element. The predictive quality and the computational efficiency is improved by applying multifield variational principles in connection with suitable assumed strain fields. The resulting element formulation does not require any Gaussian quadrature since all parts of the stiffness matrix can be integrated analytically. Furthermore, the derivation is generalized to geometrical and physical nonlinearities according to a corotational updated Lagrangian description.

Road slope introduction in vehicle route modelling

This paper deals with composite vehicle route model and its impact on energy consumption of given vehicle. Introduction of road slope in vehicle route profile may have, in most cases, significant impact on status prediction of its energy accumulation units. Presented analysis explains how ascending and descending road slopes influence energy management in hybrid electric vehicle power-train. Composite route model may provide a more realistic input data for hybrid electric vehicle simulation, therefore more realistic results.

Incremental equations for the large displacements analysis in the finite element method

Abstract Incremental equations for large displacements analysis are derived without using invalid simplifications. These equations are derived from the principle of virtual work for finite displacements. The form of the incremental equations is suited to the application of iterative solving procedures for non-linear problems, using the Newton method instead of the Newton-Raphson method. This general trend is determined by the difficulties of the formers processes and by the resulting development of iterative procedures.

Numerical Calculation of Overhead Power Lines Dynamics

Abstract This paper contains results of transient analysis of airflow around the ACSR power line cross-section in unsymmetric multi-span. The forces applied to the power line are obtained from CFD simulations, where the wind induced vibration is studied. Effect of these forces to the maximal displacement of the power line and the maximal mechanical forces in the points of attachment are studied and evaluated.

Dynamic Analysis of Overhead Power Lines after Ice–Shedding Using Finite Element Method

Abstract In this paper, the analysis of ice-shedding from ACSR conductors to its swing up height and vibration using Finite Element Method (FEM) is presented. For the numerical simulations the effective material properties of the ACSR conductor are calculated using the homogenisation method. Numerical analysis concerning vibration of one and triple-bundle conductors with icing for a whole range or on their certain parts are performed. The impact of ice-shedding to the mechanical tension in the conductors at the points of attachment is investigated and evaluated. Identification of the impact of ice-shedding from the ACSR conductors on its mechanical state may contribute to increasing the safety and quality of an electrical transmission system.

Effect of Non-Uniform Torsion on Elastostatics of a Frame of Hollow Rectangular Cross-Section

Abstract In this paper, results of numerical simulations and measurements are presented concerning the non-uniform torsion and bending of an angled members of hollow cross-section. In numerical simulation, our linear-elastic 3D Timoshenko warping beam finite element is used, which allows consideration of non-uniform torsion. The finite element is suitable for analysis of spatial structures consisting of beams with constant open and closed cross-sections. The effect of the secondary torsional moment and of the shear forces on the deformation is included in the local finite beam element stiffness matrix. The warping part of the first derivative of the twist angle due to bimoment is considered as an additional degree of freedom at the nodes of the finite elements. Standard beam, shell and solid finite elements are also used in the comparative stress and deformation simulations. Results of the numerical experiments are discussed, compared, and evaluated. Measurements are performed for confirmation of the calculated results.

Modeling of Ice-Shedding from ACSR Power Line

Abstract In this contribution, the analysis of ice-shedding from Aluminium Conductor Steel Reinforced (ACSR) power lines is presented. The impact of the icing position on the overhead power lines, the resulting jump height, and impact on attachment tension points after ice-shedding is examined. In the numerical simulations the effective material properties of the ACSR conductor is calculated using the homogenisation method. Numerical analysis of one power line and double-bundle power lines with icing over the whole range or only on certain sections of single and double-bundle power lines are performed