Applied Mechanics and Materials Vol. 611

Abstract: Failure of pipeline system can endanger human lives and cause serious damage; therefore it is necessary to check it in terms of strength and life reliability. Inspection was performed on compressor station pipeline, where in terms of resistance to brittle failure it was discovered, that the weakest point of the pipeline is the weld. At lower temperatures danger of brittle failure of weld joint can arise. To assess the strength of the pipeline in investigated cross-section, with respect to state of plane stress, strength theories were applied. Values of reduced stresses were assigned based on main normal stresses resulting from experimentally set components of state of plane stress. Fatigue assessment was done, based on currently valid standards.

Abstract: The paper deals with optimization of the production process in a selected company. The proposal of elimination of bottlenecks that were revealed in the analysis of the production process is described here in this paper. For clarity and zooming of the production process models were processed in a simulation software module from Siemens PLM Software - Tecnomatix Plant Simulation. Improvement suggestions will help to reduce the time of production operations, to improve product quality, to facilitate the work of the staff and to increase economic efficiency of production. The application of PLM software enables companies to analyze and easily develop manufacturing processes in the future, or to build new processing lines and departments [4]. It will help to optimize the current state of workplace and will allow easier data management throughout the life cycle, not just within this particular company, but throughout the corporation to which the enterprise belongs.

Abstract: The paper deals with the use of optimization methods in the design of electromechanical actuators. A brief introduction gives a theoretical basis for optimization methods. The following parts are aimed at specific opportunities and methods of the use of optimization techniques in the design of electromechanical actuators selected.

Abstract: This paper describes in the introduction part basic information concerning selection of device of technological line for the aggregates production. It is mostly focused on crushers, which during the crushing have main influence on the outer characteristics of aggregate. Correct functionality of crushers in the process of production of aggregate is crucial and relies on the selection of right mechanical influence on pieces of aggregate during crushing while respecting characteristics of crushed rocks and parameters of chosen crusher. Because of this there are written basic principles of mechanical influence on crushed material of pressure influence (jaw crusher) and with dynamic influence (impact crusher). Later are listed basic requirements for connection of each device within technological line on which follows description of an application for designing of technological line. This application allows designing the technological line with optimization of selection of devices which are using databases of available devices while still respecting listed basic rules of connection to the technological line. This way is ensured requirement of continuous material flow in production of aggregate on technological line.

Abstract: The paper provides a description of production structure reconfiguration by means of cluster analysis. The production segmentation was based on input information on the production of a valve which consists of individual parts and runs through production machines and devices integrated into given layout plan. The result of this segmentation is a proposal of a new layout plan of valve production.

Abstract: The article discusses the application of differential equations to solve large deformations of the designed slender structural elements. The structural element under design has a variable circular cross-section in longitudinal direction. It is made of a composite material based on carbon fiber and is capable of large deformations. In the solution it was necessary to consider the nonlinear deformation theory, which led to the solution of a nonlinear differential equation of second order. The creation of the differential equation describing the line of elastic deformation of a significantly curved structural element required the formulation of input equations and boundary conditions for its solution. The results obtained by means of a differential equation were compared with the numerical solution applying the finite element method. The solution presented and methodology can be used for practical application in the engineering design of fishing rods.

Abstract: The presented article is dedicated to stress state development while assessing the concentration of stresses in samples with continuously changing notches. These samples represent connecting elements of structural parts. The stress states of selected samples were determined experimentally by means of reflection photoelasticity. This method is suitable mainly for determination of stress state in the whole area in question, predominantly though for the analysis of stress concentration and its gradient in the notched area. Within the method of reflection photoelasticity, a layer was used to analyse the stress field. When loaded, this layer exhibits the ability of temporal birefringence. One of the statistical methods was selected in order to predict the stress state of other samples with bigger notches.

Abstract: This article deals about structural, mechanical and fatigue properties of an aluminium alloy EN AW 6061 (AlMg1SiCu) reinforced with SiC particles, in the initial state and in the state after intensive plastic deformation acquired by the process ECAP (Equal Channel Angular Pressing). In both states microstructures were evaluated with metallographic procedures, mechanical properties (yield strength, ultimate tensile strength, elongation) and fatigue curve at cyclic load in torsion. The main goal of this article was to study the influence of the intensive plastic deformation on an aluminium alloy reinforced with SiC particles prepared by powder metallurgy technique.

Abstract: Decision support systems mean interactive computer systems, which assist to decision making subjects to utilize both data and models to solve non-structured issues. These systems were established mainly on the basis of a risk analysis, utilizing the experience/skills, conclusion making and intuition, enabling very fast and flexible analysis with a good response, enabling the application of manager intuition and judgment this way. However, such decisions are often based on uncertain information. This fact requires the establishment of other decision support models.

Abstract: The article proposes possible increase of durability of tool steel X210Cr12 as regards working conditions under consideration of abrasive wear. From such steel tools are made for pressing wooden briquettes and saw dust waste. In practical environment a condition is held that if a material should work in abrasive wear conditions, it should have high hardness and should contain carbides in the structure. The proposed paper deals with the heat and chemical-heat treatment (nitriding) of tool steel which is working in hard abrasive wear conditions. From the obtained results it is not easy to conclude a definitive conclusion or to set the boundaries between the factors that are responsible for wear resistance. It is shown that the chemical-heat treatment can in the last step of the heat treatment lead to an increase or even to a decrease in the abrasive wear resistance of the material. The aim of the paper is to set a proper heat treatment of materials used for pressing in abrasion wear conditions.