Mechanics and Control
Loading...
ISSN 2083-6759
e-ISSN: 2300-7079
Issue Date
2013
Volume
Vol. 32
Number
No. 4
Description
Journal Volume
Mechanics and Control
Vol. 32 (2013)
Projects
Pages
Articles
Numerical simulation and co-simulation in analysis of manipulators’ dynamics
(2013) Baran, Dariusz; Lisowski, Wojciech
Application of general purpose computing environments to analysis of manipulators’ dynamics gives ability to select elastically the model structure and analysis algorithms, as well as full access to the intermediate results, however, it often requires introduction of various simplifications of the model under consideration. The alternative approach consists in application of the specialized software packages that allow the use of more sophisticated models, but at the cost of restricted access to the intermediate results as well as the limited range of possible modifications of models and solution algorithms. The authors focused on application of the co-simulation technique in analysis of manipulators’ dynamics. Co-simulation consists in application of specialized software packages to formulation of the dynamic model. Next, the model is simulated with use of a general purpose computing environment and co-operating specialized software package. The authors used Matlab/Simulink computing environment and MD ADAMS software package. The paper presents comparison of results, problems of application, as well as remarks on educational applicability of manipulator dynamics analysis with use of the simulation and the co-simulation techniques. Two examples of a manipulator dynamics modelling were considered. One example with a considerably simplified mass spatial distribution, and another one with a mass distribution corresponding to a real commercial manipulator. The achieved analysis results confirmed that application of the co-simulation technique eases the use of complex models in analysis of manipulator dynamics with use of the general purpose computing environments.
Coupled problems of interaction of deformable bodies and liquid of high pressure
(2013) Šumel'čik, Kseniâ; Kuz'menko, Vasil' Ìvanovič
Nowadays the problems of interaction between solids and liquid under high and extremely high pressure are fairly relevant. So the main aim of presented research work is: creating the mathematical models and methods to investigate the interaction of bodies that include cracks filled with a compressible liquid or gas. The coupled problem of interaction of nonlinear elastic bodies and liquid of high pressure was considered. The pressure exerted by a liquid or gas present in the cavities of solids depends on the deformation of the body. In turn the deformation is caused by the pressure inside the cavity. The interaction between a deformable body and liquid is presented as a variational problem. The iterative splitting process of the coupled problem was proposed as well as the algorithm of numerical solution based on variational approach and finite element method. The software which allows calculating the stress state of an elastic body for some classes of problems was developed basing on the algorithm of splitting. The plane problem with cavity and solid stamp which imposes pressure on the boundary was considered and the numerical solution was computed using created software.
Enhancing mesh adaptation capabilities of GetFEM++ “FEM engine” with MAdLib library
(2013) Perduta, Anna
This paper describes enhancing mesh adaptation capabilities of GetFEM++ library. GetFEM++ is a versetile software package in C++ for implementing FEM based solvers for partial differential equations. Although GetFEM++ offers a wide range of mathematic tools for model descripion and discretization, it does only provide basic mesh refinement facilities. To enhance GetFEM++ capabilities, a mesh adaptation package MAdLib is used. The paper discusses basic requirements for mesh adaptation packages and presents MAdLib basic usage. The paper discusses implementation issues related to integration of both libraries. Examples illustrate capabilities of mesh adapation package and FEM framework extended by mesh adaptation facilities.
Finite element implementation of nonlinear thermo-elasticity as typical coupling of diffusion and momentum balance
(2013) Putanowicz, Roman; Jaśkowiec, Jan; Pluciński, Piotr; Stankiewicz, Anna
The formulation and algorithmic aspects of nonlinear thermo-elasticity are reviewed in the paper. The attention is focused on coupling due to thermal expansion and temperature dependence of elastic model parameters, and on the consistent linearization of the ensuing nonlinear set of equations for two-field finite elements. Non-stationary heat flow, static loading and small strains are assumed. The solutions of some benchmark examples, obtained using the developed finite element environment FEMDK, are presented. The formulation has a more general application domain in the context of arbitrary coupling of a nonstationary diffusion proces and momentum balance.
Mathematical modelling of utilization waste gases from industrial furnaces
(2013) Rusinowski, Henryk; Milejski, Adam; Buliński, Zbigniew
Combustible waste gases are by-products of many technological processes. They vary in their calorific value and are used to decrease the usage of gases whose calorific value is higher. Coke oven gas from the coking process and process gases from an electric furnace in a copper plant are examples of such gases. Composition and calorific value of coke oven gas depend on coking parameters as well as on the type and quality of coal. The most common process where the coke oven gas is used is the process of heating combustion air in a heat regenerator. The gases from the electric furnace (due to low calorific value) require post combustion at the beginning of their disposal process. The paper addresses mathematical modelling of a coke oven battery regenerator as well as mathematical modelling of post combustion and cooling the electric furnace process gases. The regenerator mathematical model was elaborated for the simplified geometry of a real object making the assumptions for the heat transfer equations. The post combustion and cooling processes of the electric furnace gases are modelled with the aid of the Ansys software. This software was used for both elaborate simplified geometry of the analysed object and carry out the simulations. Mathematical description of occurring processes includes in this case combustion, turbulence and heat transfer.