Chosen Numerical Algorithms for Interval Finite Element Analysis

AbstractOur paper presents chosen computational algorithms for solution of finite element models with structural uncertainties. An application of the chosen approaches will be presented–the first one, a simple combination of only inf-values or only sup-values; the second one presents full combination of all inf-sup values; the third one uses the optimizing process as a tool for finding out an inf-sup solution and last one is the Monte Carlo method as a comparison tool

Numerical study of large scale truss construction with structural uncertainties

The paper deals with efficiency and usability problem for the chosen solution methods for mechanical systems with structural uncertainties. They are significantly influencing the analysis results and the analysis itself. An application of the chosen approaches will be presented – the first one, a simple combination of only inf-values or only sup-values; the second one presents full combination of all inf-sup values; the third one uses the optimizing process as a tool for finding out an inf-sup solution and last one is Monte Carlo method as a comparison tool.The paper deals with efficiency and usability problem for the chosen solution methods for mechanical systems with structural uncertainties. They are significantly influencing the analysis results and the analysis itself. An application of the chosen approaches will be presented – the first one, a simple combination of only inf-values or only sup-values; the second one presents full combination of all inf-sup values; the third one uses the optimizing process as a tool for finding out an inf-sup solution and last one is Monte Carlo method as a comparison tool

SYNTHESIS OF A PUMPING UNIT WITH CONSIDERATION OF A FLEXIBLE MEMBER IN THE SYSTEM

To achieve correct function and maximal effectiveness of a pumping unit, it is necessary to correctly design the input dynamic parameters. This paper will present sensitivity analysis, which aims to find appropriate input parameters needed to realize the prescribed work tasks from the point of view of consideration of flexible member in the system

Numerical methods for analysis of mechanical systems with uncertain parameters

The paper presents new and improved numerical methods designed for analysis of mechanical systems with uncertain parameters. Uncertain parameters in mechanical systems are described by means of possibility theory. The main representatives of this theory are fuzzy and interval numbers. Algorithms using interval and fuzzy numbers are incorporated into the analysis. The possibilities and efficiency of suggested methods and algorithms are tested by programs created in the environment of the software package MATLAB

Numerical methods for analysis of mechanical systems with uncertain parameters

The paper presents new and improved numerical methods designed for analysis of mechanical systems with uncertain parameters. Uncertain parameters in mechanical systems are described by means of possibility theory. The main representatives of this theory are fuzzy and interval numbers. Algorithms using interval and fuzzy numbers are incorporated into the analysis. The possibilities and efficiency of suggested methods and algorithms are tested by programs created in the environment of the software package MATLAB

Correlation between shape factor and mechanical properties of graphitic cast irons

The evaluation of shape factor (circularity) is a subject of interest in many fields of applications such as medicine and industrial processes. The shape factor plays an important role in materials science as a way to understand the relationship between microstructure and mechanical properties of technical materials. The paper deals with measurement of shape factor of graphitic particles with the aim to understand the influence of microstructure (especially shape of graphite) on mechanical properties of graphitic cast iron

Impact Toughness of FRTP Composites Produced by 3D Printing

The additive manufacturing represents a new production method of composites reinforced with a continuous fibre. In recent times, the material produced by this new manufacturing method constituted a replacement for conventional materials—e.g., steel in many technical areas. As the research on FRTP composites is currently under way, the purpose of this article is to add information to the mosaic of studies in this research area. The scientific articles published until now have focused especially on mechanical testing, such as tensile and bending mechanical testing and their assessment. Therefore, the authors decided to carry out and assess the impact test of the FRTP composites produced by 3D printing because this area offers a large extent of research activities. We observed the influence of the reinforcement in the form of the micro-fibre carbon in the thermoplastic (Onyx) or a continuous reinforcement fibre in the lamina on the specimen’s behaviour during the impact load processes. The results of the experimental measurements show that the presence of a continuous fibre in the structure significantly affects the strength of the printed specimens; however, the design process of the printed object has to take into account the importance of selecting a suitable fibre type. The selection of a suitable strategy for arranging the fibre in the lamina and the direction of the impact load against the position of the fibre seem to be very important parameters

Design of a computational model for multi-body contact of deformable bodies in the flowing fluid

The article deals with the design and testing of a computational model for multi-body contact of deformable bodies in the flowing fluid. The computational model will be designed to allow easy modify the impact area of deformable bodies and their shape. The computational model must allow the application of an endless cycle of bodies impact with the possibility of restarting and calculating the following time intervals for collision of bodies

Comparison study of the computational methods for eigenvalues IFE analysis

The goal of the paper is to present a non-traditional computational tool for structural analysis with uncertainties in material, geometric and load parameters. Uncertainties are introduced as bounded possible values— intervals. The main objective has been to propose algorithms for interval modal and spectral computations on FEM models suggested by authors and their comparison with Monte Carlo

Influence of Fiber Deposition and Orientation on Stress Distribution in Specimens Produced Using 3D Printing

Continuous fiber fabrication technology, developed by Markforged and used in MarkTwo printers, allows using of reinforcing fibers, which improve mechanical properties of produced parts. The technology enables choosing of two fiber deposition strategies: isotropic fiber fill and concentric fiber fill. With the isotropic fiber fill, there is an option to set up various fiber angles in each layer. The article is focused on stress distribution analysis using FEM in a matrix and individual reinforcing fibers of specimens loaded to uniaxial tension. Main observed parameters are stresses in matrix and fiber and usage of the reinforcing material