Department of Structural Mechanics and Computer Aided Engineering
XXIII R-S-P Seminar, Theoretical Foundation of Civil Engineering (23RSP) (TFoCE 2014) PDF Print E-mail
tfoce 2014XXIII R-S-P Seminar, Theoretical Foundation of Civil Engineering (23RSP) (TFoCE 2014)
Edited by Marian Drusa, Ruzica R. Nikolic and Marian Marschalko, Procedia Engineering, Volume 91, Pages 1-492 (2014)

Isogeometric Analysis as a New FEM Formulation - Simple Problems of Steady State Thermal Analysis, Zbigniew Kacprzyk, Katarzyna Ostapska-Łuczkowska, Pages 87-92, doi:10.1016/j.proeng.2014.12.018
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Abstract: The subject of this article concerns Isogeometric Analysis as a new formulation within Finite Element Method. Motivation for this new approach was presented together with theoretical foundations of the method. The main subject of the paper is numerical implementation of the method in the Matlab environment. Special focus was put on the new concept of element and new geometry data interpretation in terms of analysis. Object oriented programming was utilized to produce more universal tool for future investigations. Several examples for Poisson's partial differential equation solution were presented. The h-refinement was utilized to show method convergence. Steady state thermal analysis was performed with temperatures and heat flux as boundary conditions. Quick geometry data transfer and mesh refinement from Rhino software with Grasshopper plug-in was also prepared and described in the paper. Finally, authors' conclusions concerning new method were presented and comparison between FEM and IGA was made on the basis of the studied examples.
Keywords: Isogeometric Analysis (IGA); Finite Element Method (FEM); B-spline; NURBS; T-spline; CAD; Computer Aided Engineering ;

Dynamics of Multi-body Mechanical Systems with Unilateral Constraints and Impacts, Artur Zbiciak, Zofia Kozyra, Pages 112-117, doi:10.1016/j.proeng.2014.12.024
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Abstract: The paper deals with mathematical description and computer simulation of multi-body dynamical systems with constraints imposed on displacements and velocities. Such mechanical systems contain a finite number of material points, whose motion is limited by unilateral constraints. The mathematical description of the problem, concerning the interaction between material points and unilateral constraints, is presented. The dynamic problem was defined in order to evaluate accelerations of elements and reactions of constraints. Moreover, the impact problem was formulated. The solution of the impact problem determines non-continuous change in velocities of elements and impulses of constraints' reactions.
Keywords: dynamics; non-smooth mechanics; multi-body systems; unilateral constraints; impact; contact; non-linear vibrations ;

Traditional Design versus BIM Based Design, Ireneusz Czmoch, Adam Pękala, Pages 210-215, doi:10.1016/j.proeng.2014.12.048
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Abstract:The paper shortly presents the history and development of the traditional design in civil engineering. Next, the idea of Building Information Modelling (BIM) and its practical benefits are described. Main part of the paper is devoted to discussion about what kind of difficulties we may encounter during the implementation of the BIM technology and how they are related to the potential benefits. Case study presents the existing design prepared in BIM technology.
Keywords: traditional design; civil engineering; CAD; BIM

Building Information Modelling – 4D Modelling Technology on the Example of the Reconstruction Stairwell, Zbigniew Kacprzyk, Tomasz Kępa, Pages 226-231, doi:10.1016/j.proeng.2014.12.051
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Abstract: Building Information Modelling (BIM) is a process that involves creating, generating, managing and using a digital representations of physical and functional characteristics of building. The use of the term 4D is intended to refer to the fourth dimension: time, i.e. 4D is 3D + schedule (time). The role of 4D BIM is to add a new dimension to 3D CAD or solid modelling—that is, 4D BIM adds a fourth dimension of Time to the 3D Space of CAD solid modelling on computer. In the paper show the project entirely made using 4D BIM
Keywords: Building Information Modelling (BIM); 3D design; CAD; architectural engineering and construction (AEC) software
Złota Kreda PDF Print E-mail

Złota Kreda
A note on optimal design of multiphase elastic structures PDF Print E-mail
structural optimizationA note on optimal design of multiphase elastic structures
N. Briggs, A. Cherkaev, G. Dzierżanowski
Structural and Multidisciplinary Optimization: Volume 51, Issue 3 (2015), Page 749-755,
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The paper describes the first exact results in optimal design of three-phase elastic structures. Two isotropic materials, the "strong" and the "weak" one, are laid out with void in a given two-dimensional domain so that the compliance plus weight of a structure is minimized. As in the classical two-phase problem, the optimal layout of three phases is also determined on two levels: macro- and microscopic. On the macrolevel, the design domain is divided into several subdomains. Some are filled with pure phases, and others with their mixtures (composites). The main aim of the paper is to discuss the non-uniqueness of the optimal macroscopic multiphase distribution. This phenomenon does not occur in the two-phase problem, and in the three-phase design it arises only when the moduli of material isotropy of "strong" and "weak" phases are in certain relation.
Optymalizacja topologiczna konstrukcji inżynierskich. PDF Print E-mail
Projekt badawczy Narodowego Centrum Nauki pt.:
Optymalizacja topologiczna konstrukcji inżynierskich. Ujęcie syntetyzujące metody: projektowania anizotropii z wolnego wyboru, projektowania materiałów niejednorodnych oraz metodę siatek typu Michella,
Kierownik: prof. dr hab. inż. Tomasz Lewiński,
Politechnika Warszawska; Wydział Inżynierii Lądowej,
środki przyznane: 772 040 zł,
zajął 5. miejsce spośród 188 projektów złożonych w ramach konkursu: OPUS, Panel ST 8 (data ogłoszenia: 16 IX 2013 r.). Do drugiego etapu zakwalifikowano 47 wniosków; do finansowania skierowano 32 wnioski.

Projekt ten będzie wykonywany w ramach umowy:
zawartej w dniu 15 lipca 2014 r. pomiędzy
NCN a Politechniką Warszawską.
Nr projektu: 2013/11/B/ST8/04436
Okres realizacji: 15.07.2014-14.07. 2017, przedłużony aneksem do 14.12.2017.
Informatyzacja projektowania budowlanego PDF Print E-mail
budmika2014 zk-mInformatyzacja projektowania budowlanego, Zbigniew Kacprzyk, Konferencja Budmika 2014, Poznań, 23-25 kwietnia 2014 roku

Wykład „Informatyzacja projektowania budowlanego" ma na celu przybliżenie współczesnych narzędzi pracy projektanta budowlanego na tle przełomowych odkryć w informatyce , w mechanice obliczeniowej i modelowaniu geometrycznym.
Z całego obszaru „informatyzacji projektowania" dokładniej omówię informatyzację obliczeń inżynierskich oraz informatyzację modelowania geometrycznego. Na końcu zajmę się problemami integracji oprogramowania – czyli problemami wymiany danych.

Prezentacja>>pdf10.56 MB
A stress-based formulation of the free material design problem with the trace constraint and multiple load conditions PDF Print E-mail
 A stress-based formulation of the free material design problem with the trace constraint and multiple load conditions. structurak o f
S. Czarnecki, T.Lewiński,
Structural and Multidisciplinary Optimization, 2014 in press
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The paper deals with minimization of the weighted sum of compliances related to the load cases applied non-simultaneously. The design variables are all components of the Hooke tensor, subject to the isoperimetric condition bounding the integral of the sum of the Kelvin moduli. This free material design problem is reduced to an equilibrium problem – in two formulations – of an effective body with locking. The stress-based formulation reduces to minimization of an integral of a certain norm of stress fields over the stress fields which equilibrate the given loads. The equivalent displacement-based formulation involves a locking locus defined by using a norm being dual to the previous one. The optimal Hooke tensor is determined by using the stress fields solving the auxiliary locking problem. To make the optimal Hooke tensor positive definite one should consider at least 3 load conditions in the 2D case and not less than 6 load conditions in the 3D case.
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