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1
Content available remote System doboru mocowań zabudów samochodów ciężarowych
PL
W pracy przedstawiono program mający na celu dobór typu, liczby oraz rozmieszczenia mocowań zabudów na samochody ciężarowe. Na podstawie dokumentacji producenta zabudów opracowano katalog mocowań, które poddano następnie analizie wytrzymałościowej. Zastosowane metody optymalizacji jednowymiarowej pozwoliły na wyznaczenie sił dla każdego modelu mocowania, które powodują naprężenia zbliżone do granicy plastyczności materiału. Opracowany program dobiera mocowania na podstawie wytycznych producenta podwozi i obliczonych sił: hamowania, wiatru, odśrodkowej oraz siły wynikającej z jazdy po wzniesieniach.
EN
The paper presents computer application for selecting type, number and location of truck body mountings. Based on manufacturer’s technical documentation, a body mounting catalogue has been made. Each mounting model has been verifed by FEM software. Forces, which cause tension close to yield strength, for each model has been designated using one dimensional optimization methods. The application selects body mounting based on car manufacturer guidelines and calculated forces: bracking force, wind power, centrifugal force and force that is result of slopes driving.
EN
This paper deals with the identification of material parameters at a microscale on the basis of measurements at a macroscale. Inhomogeneous materials such as composites and porous media are considered. Numerical homogenization with the use of a representative volume element is performed to obtain a macroscopically homogenized equivalent material. The evolutionary algorithm is applied as the global optimization method to solve the identification task. Modal analysis is performed to collect data necessary for the identification. Different ranges of measurement errors are considered. A finite element method is employed to solve a boundary-value problem for both scales.
3
Content available remote Global identification of the laminates’ material parameters
EN
The paper is devoted to the global identification of material parameters of the single layer of the laminate. The measurement data for identification are derived from the laminate strength tests in the form of the three-point flexure test and the tensile test with a video extensometer. The evolutionary algorithm is applied to perform the identification procedure. Finite element method commercial software is employed to solve a boundary-value problem for laminates. Examples presenting effectiveness of the proposed method are included.
PL
Artykuł jest poświęcony globalnej identyfikacji parametrów materiałowych pojedynczej warstwy laminatu. Dane pomiarowe dla identyfikacji pochodzą z prób wytrzymałościowych w postaci próby trójpunktowego zginania oraz próby rozciągania z zastosowaniem wideoekstensometru. Algorytm ewolucyjny został zastosowany jako metoda optymalizacji. Komercyjne oprogramowanie metody elementów skończonych zostało użyte w celu rozwiązania zadania brzegowego dla laminatów. Zamieszczono przykłady prezentujące skuteczność proponowanego podejścia.
EN
The paper deals with the multiobjective and multiscale optimization of heterogeneous structures by means of computational intelligence methods. The aim of the paper is to find optimal properties of composite structures in a macro scale modifying their microstructure. At least two contradictory optimization criteria are considered simultaneously. A numerical homogenization concept with a representative volume element is applied to obtain equivalent macro-scale elastic constants. An in-house multiobjective evolutionary algorithm MOOPTIM is applied to solve the considered optimization tasks. The finite element method is used to solve the boundary-value problem in both scales. A numerical example is attached.
5
Content available remote Modelowanie wieloskalowe gradientowych kompozytów włóknistych
PL
W pracy przedstawiono metodę modelowania wieloskalowego materiałów gradientowych na przykładzie kompozytu włóknistego o zmiennej średnicy włókna. Celem modelowania było wyznaczenie makroskopowych własności materiałowych określających zmiany w materiale gradientowym. Obliczenia wykonano w oparciu o analizę naprężeń z wykorzystaniem metody elementów skończonych (MES) oraz homogenizacji numerycznej.
EN
The paper presents a method for multiscale modelling of graded materials, on the example of fiber composite with varying fiber diameter. The aim of modelling was to determine the macroscopic material properties, which define changes in graded material. Calculations were based on stress analysis by means finite element method and numerical homogenization.
6
Content available remote Komputerowy system wspomagający projektowanie zabudów wywrotek
PL
W pracy przedstawiono opracowany system wspomagający projektowanie, analizę wytrzymałościową i optymalizacje wariantową zabudów wywrotek na samochody ciężarowe. System napisano w języku PHP z wykorzystaniem bazy danych MySQL oraz serwera witryn internetowych Apache i jest on dostępny dla użytkownika jako strona internetowa. Zadaniem systemu jest dobór rodzaju, liczby i wymiarów elementów konstrukcyjnych, jak również tworzenie dokumentacji technologicznej produktu. System umożliwia użytkownikowi edycję otrzymanych wyników w celu dopasowania projektu do konkretnych wymagań. Opracowany model konstrukcji jest weryfikowany wytrzymałościowo przy wykorzystaniu oprogramowania MES. Możliwa jest również optymalizacja konstrukcji ze względu na wybrane kryteria.
EN
The paper presents an developed computer aid system for design, strength analysis and variant optimization of dump body for trucks. The system is written in PHP using MySQL database and Apache server web sites and it is available to the user as a web page. The purpose of the system is the choice of the type, number and dimensions of structural elements, as well as creating technological documentation of the product. The system allows the user to edit the results in order to design for specific requirements. The model is verified using FEM software. It is also possible to optimize the structure due to the selected criteria.
EN
The paper deals with the two-scale approach to the identification of material constants in composite materials. Structures made of unidirectionally fibre-reinforced composites are examined. Composite constituents’ elastic constants in a micro scale are identified on the basis of measurements performed in a macro scale. Numerical homogenization methods using a representative volume element are employed. Static (displacements in sensor points) and dynamic (eigenfrequencies) data are considered as measurements. Ideal and disturbed measurements are taken into account. Computational intelligence methods in the form of evolutionary algorithms and artificial immune systems are used to perform the identification procedure. Finite element method is used to solve the boundary-value problem for composites in both scales. Numerical examples presenting the effectiveness of the proposed approach are attached. Statistical data are considered to compare the efficiency of the identification procedure for both algorithms and different measurement data.
8
Content available remote Evolutionary identification of laminates' granular parameters
EN
The paper deals with the identification of material constants in simple and hybrid laminates. It is assumed that identified constants are non-deterministic and can be described by means of different forms of the information granularity represented by interval numbers, fuzzy numbers or random variables. The Two-Stage Granular Strategy combining global (Evolutionary Algorithm) and local (gradient method supported by an Artificial Neural Network) optimization techniques is used to solve the identification problems. Finite Element Method in the granular form is used to solve the direct problem for laminates. Modal analysismethods are employed to collect measurement data for the identification process. Numerical examples presenting effectiveness of the strategy are enclosed.
EN
The paper deals with the application of the global optimization methods to the multi-objective optimization of laminates. A multi-layered, fibre-reinforced and hybrid laminates are considered. Different optimization criteria connected with the laminates' cost, modal properties and stiffness are taken into account. As the optimization criteria usually cannot be satisfied simultaneously, the multi-objective optimization methods are employed. The multi-objective evolutionary algorithm with the Pareto approach is used as the global optimization method. The Finite Element Method is used to solve a boundary-value problem for the laminates. The stacking sequence and the number or plies made of different materials are design variables. The discrete as well as continuous fibre orientation angles in particular plies are considered. Numerical example presenting non-dominated solutions for two contradictory optimization criteria is attached.
EN
The paper deals with the identification of material constants in multi-layered composites. Simple and hybrid (with laminas made of different materials) laminates are considered. Material constants are presented in a stochastic form to model their uncertainty. The Evolutionary Algorithm based on such representation of the data is used as the global optimization method. Chromosomes are represented by multidimensional random vectors consisting of random genes in the form of independent random variables with the Gaussian density probability functions. The Stochastic optimization problem is replaced by a deterministic one by evolutionary computing of chromosomes having genes consisting of mean values and standard deviations. Modal analysis methods are employed to collect measurement data necessary for the identification. The Finite Element Method in Stochastic version is used to solve the boundary-value problem for laminates. Numerical examples showing efficiency of the method are presented.
EN
The paper deals with identification of material constans in fibre-reinforced laminates. The Evolutionary Algorithm is used as the global optimization method. The grandiet method supported by the Artificial Neutral Network is used as the local optimization method. Material constans are presented in the form of fuzzy numbers to model their uncertainty. Two types of laminates are considered: simple and hybrid ones. Modal analysis methods are used to collect data necessary for the identification process. The Finite Element Method in fuzzy version is used to solve the direct problem for the laminates. Numerical examples are attached.
12
Content available remote Evolutionary multi-objective optimization of hybrid laminates
EN
The aim of the paper is to prepare an efficient method of the optimization of the hybrid fibre-reinforced laminates. Since the several optimization criteria which cannot be satisfied simultaneously are proposed, the multi-objective optimization methods have been employed. Different optimization criteria connected with the laminates' cost, the modal properties and the stiffness are considered. The multi-objective evolutionary algorithm which uses the Pareto approach has been used as the optimization method. To solve the boundary-value problem the finite element method commercial software has been employed. Numerical examples presenting the effectiveness of the proposed method are attached.
EN
The paper deals with the optimization and identification of hybrid fibre-reinforced laminates. Two tasks are considered: i) the ply orientations optimization, ii) the material constants identification. Different optimization and identification criteria connected with the modal analysis are considered. The evolutionary algorithm is used as the optimization and identification method. In order to accelerate the calculations, the distributed version of the evolutionary algorithm is employed. Finite element method software is used to solve the direct problem for the laminates. Numerical examples of optimization and identification are attached.
14
Content available remote Intelligent computing in inverse problems
EN
This paper presents a review of intelligent computing techniques in solving inverse mechanics problems. These techniques are based on Evolutionary Algorithms (EAs) and the coupling of Evolutionary Algorithms (EAs) and Artificial Neural Networks (ANNs) in the form of Computational Intelligence Systems (CISs). The main attention was focused on the identification of the defects such as voids or cracks in structures on the basis of the knowledge about displacements, temperature and eigenfrequencies. The identification of the unknown number, position, size and kind of defects in the elastic structures is shown. The paper contains a lot of tests and numerical examples.
15
Content available remote Evolutionary shape optimization in fracture problems
EN
The aim to the paper is to optimize 2-dimensional elastic structures subjected to cyclic load. The loading can result in crack forming, so the aim of the optimization is to reduce the possibility of crack growth. The number of loading cycles necessary to crack growth is maximized. To solve the optimization task the evolutionary algorithm is used. The boundary element method is applied to solve the crack problem. In order to reduce the number of design variables the parametrical NURSB curves are used to model the geometry of parts of the structural element boundary.
PL
W artykule przedstawiono ewolucyjną metodę optymalnego projektowania konstrukcji mechanicznych. Metoda ta oparta jest na połączeniu algorytmów ewolucyjnych (AE) oraz metody elementów skończonych (MES). Metoda ewolucyjnego optymalnego projektowania umożliwia optymalizację kształtu, topologii oraz parametrów materiału ciał sprężystych i niesprężystych, a także identyfikację parametrów materiału i defektów. Zastosowanie algorytmów ewolucyjnych w optymalizacji pozwala z dużym prawdopodobieństwem na znalezienie optymalnego rozwiązania globalnego tylko przy znajomości funkcji przystosowania, bez konieczności obliczaniajej gradientu. Do obliczenia wartości funkcji przystosowania wykorzystano wyniki analizy MES za pomocą oprogramowania MSC/Nastran i MSC/Marc.
EN
The evolutionary method for optimal design of mechanica] structures is presented in the article. The method is based on coupling of evolutionary algorithms (EA) and the finite element method (FEM). The presented method enables optimization of the shape and topology and the identification of material parameters and defects. The application of the evolutionary algorithms in optimization allows finding the glob al optimum with great probability and only the fitness function must be computed, there is no need to evaluate its gradients. The FEM programs MSC/Nastran and MSC/Marc were used to solve the direet problem and evaluate the fitness function value.
EN
This chapter deals with applications of evolutionary algorithms to the topology optimization of elastic structures, shape optimization of elasto-plastic structures, the identification of voids and cracks in structures under dynamical loading and the identification and optimization of boundary conditions in cracked structures.
18
Content available remote Evolitionary computation in optimization and identification
EN
The aim of the paper is to present the application of the evolutionary algorithms to selected optimization and identification problems of mechanical systems. The coupling of evolutionary algorithms with the finite element method and the boundary element method creates a new artificial intelligence technique that is very suitable in computer aided optimal design and defect detection. Several numerical examples for optimization and identification are presented.
EN
This paper deals with an application of adjoint variable method and the dual boundary element method to sensitivity analysis of an arbitrary boundary functional with respect to shape transformation of the external boundary and translation, rotation atul scale change of the crack.
PL
Niniejsza praca przedstawia zastosowanie metody zmiennych sprzężonych oraz dualnej metody elementów brzegowych do analizy wrażliwości dowolnego funkcjonału brzegowego względom transformacji brzegu zewnętrznego oraz translacji, rotacji i ekspansji szczeliny.
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