Wyniki 1-2 spośród 2 dla zapytania: authorDesc:"Mateusz Konieczny"

Analysis of the impact of slot geometry on the stresses distribution in a plate of S235JR steel subjected at biaxial load DOI:10.15199/28.2018.6.5

  1. INTRODUCTION One of the causes of the formation and development of fatigue cracks is the occurrence of local stress concentration, arising around openings, crevices, undercuts, angular recesses in the material and flanges. A number of analytical methods [1], experimental [2], numerical [3, 4] are known to address the problem of stress state analysis in plates or discs containing holes and slots. Mathematical analysis, experimental measurement and numerical analysis show that in a loaded structural member or machine element, near changes in the section, distributions of stress occur in which the peak stress reaches much larger magnitudes than does the average stress over the section. This increase in peak stress near holes, grooves, notches, sharp corners, cracks, and other changes in section is called stress concentration. The section variation that causes the stress concentration is referred to as a stress raiser. An isotropic plate with central located hole (circular hole, elliptical slot, flat slot) under longitudinal loading, have found widespread applications in various fields of engineering such as aerospace, marine, automobile and mechanical. For design of plates with hole, accurate knowledge of deflection, stresses and stress concentration are required. Stress concentration arises from any abrupt change in geometry of plate under loading. As a result, stress distribution is not uniform throughout the cross section. Failures such as fatigue cracking and plastic deformation frequently occur at points of stress concentration [5]. There are many issues in the literature regarding the analysis of stress concentration, deflections, stress concentration factor and stress intensity factor in plates or discs weakened with holes of various shapes. The studies were submitted homogeneous isotropic plates made of elastic material [6], orthotropic [7], composite [8÷10] and made of steel [11, 12]. As can be seen from the literatur[...]

Research of maximum stresses zones in circular perforated plates made of S235JR steel loaded with concentrated force DOI:10.15199/28.2019.2.4

  1. INTRODUCTION Present engineering constructions are characterized by a decrease in terms of the safety factor, that is why calculations of strength, stiffness and stability of thin-walled construction elements are becoming some of the important aspects in all branches of technology, especially such as chemical engineering. There are many applications of perforated plates, e.g. in pressure vessels, chemical equipment (heat exchanger tube screens) [1÷3], oil refineries, aircraft and spacecraft parts, aircraft, robots, transport containers, box conveyors or as elements of loose material screens, which can be subjected to a load that varies over time. This type of girders (perforated plates) can also act as mounting boards in which holes are made for various operational reasons [4]. In practical problems of design, it is often necessary to determine stresses and deflections in such plates, which are loaded with static forces acting perpendicular to their surface. Due to the wide application of perforated elements in many branches of industry, it is advisable to undertake studies involving the analysis of the state of stress such elements subjected to a normal load. Knowledge of the state of stress will offer optimal design; and thus, safe operation of devices in which these types of components are used has been made more feasible [5÷7]. In the literature many attempts were made to analyse stress concentration, deflections, strains, stress concentration factor and stress intensity factor in perforated plates weakened because of openings comprised in them. The analytical method [8÷10], the experimental method [11÷14] and the numerical method [15÷21] were used to evaluate the parameters of perforated plates. During the analysis of perforated plates, various design parameters were varied, which have a significant impact on the nature of the correct operation of these plates, i.e.: type of material (isotropic, orthotropic, composite [...]

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