Methodology for repeated load analysis of composite structures with embedded magnetic microwires

The article processes issue of strength of cyclically loaded composite structures with the possibility of contactless stress measuring inside a material. For this purpose a contactless tensile stress sensor using improved induction principle based on the magnetic microwires embedded in the composite structure has been developed. The methodology based on the E-N approach was applied for the analysis of the repeated load of the wing hinge connection, including finite element method (FEM) fatigue strength analysis. The results proved that composites in comparison with the metal structures offer significant weight reduction of the small aircraft construction, whereas the required strength, stability and lifetime of the components are remained

Methodology for repeated load analysis of composite structures with embedded magnetic microwires

The article processes issue of strength of cyclically loaded composite structures with the possibility of contactless stress measuring inside a material. For this purpose a contactless tensile stress sensor using improved induction principle based on the magnetic microwires embedded in the composite structure has been developed. The methodology based on the E-N approach was applied for the analysis of the repeated load of the wing hinge connection, including finite element method (FEM) fatigue strength analysis. The results proved that composites in comparison with the metal structures offer significant weight reduction of the small aircraft construction, whereas the required strength, stability and lifetime of the components are remained

Modification of the 3D printer for the processing of the high-performance thermoplastic polymers in the production process of transport system components

Nowadays, the ability to process the high-performance thermoplastic polymers has been still the domain of the industrial 3D printers. This article describes the possibilities of the commercial 3D printer modification to achieve the required boundary conditions for the processing of the high-performance thermoplastics with adequate mechanical properties. These materials have a very high melting point, and it is inevitable to ensure this increased temperature in the entire print volume. Therefore, it was necessary to perform the numerical simulations focused mainly on the thermal load of the 3D printer construction. Consequently, the simulation results were experimentally verified, and the optimal material in terms of its density and mechanical properties was selected

Application and mechanical properties of thermoplastic polymers for the additive manufacturing of transportation systems

The gradual integration of the additive manufacturing into the common practice involves more complex requirements for the used materials. Although the additive manufacturing was mainly used for the rapid-prototyping purposes, with the development of the high-performance thermoplastic materials, the produced components can be applied not only in the laboratory conditions, but also in the real operation. Therefore, it is necessary to consider also the environmental influences that can significantly shorten the component lifetime. This article presents the 3D printing process for the selected thermoplastic polymers and the experimental verification of the strength analysis of the universal sensor holder together with the quantitative and qualitative comparison of their mechanical properties

Modification of the 3D printer for the processing of the high-performance thermoplastic polymers in the production process of transport system components

Nowadays, the ability to process the high-performance thermoplastic polymers has been still the domain of the industrial 3D printers. This article describes the possibilities of the commercial 3D printer modification to achieve the required boundary conditions for the processing of the high-performance thermoplastics with adequate mechanical properties. These materials have a very high melting point, and it is inevitable to ensure this increased temperature in the entire print volume. Therefore, it was necessary to perform the numerical simulations focused mainly on the thermal load of the 3D printer construction. Consequently, the simulation results were experimentally verified, and the optimal material in terms of its density and mechanical properties was selected

Application and mechanical properties of thermoplastic polymers for the additive manufacturing of transportation systems

The gradual integration of the additive manufacturing into the common practice involves more complex requirements for the used materials. Although the additive manufacturing was mainly used for the rapid-prototyping purposes, with the development of the high-performance thermoplastic materials, the produced components can be applied not only in the laboratory conditions, but also in the real operation. Therefore, it is necessary to consider also the environmental influences that can significantly shorten the component lifetime. This article presents the 3D printing process for the selected thermoplastic polymers and the experimental verification of the strength analysis of the universal sensor holder together with the quantitative and qualitative comparison of their mechanical properties

Methodology for structural analysis of hyperelastic materials with embedded magnetic microwires

The article deals with the mechanical tensile tests of the hyperelastic materials and its mechanical properties estimation using embedded magnetic microwires. Hyperelastic materials are specific because of the elasticity, which means that they return to their original shape after the forces have been removed. The article processes the issue of the structural analysis of the hyperelastic materials, where the methodology for hyperelastic materials laws together with its implementation in the Creo-Simulate software is described. After the comparison of the simulation results with the experimental results a very good compliance was achieved. The created methodology together with the application of the tensile stress sensors based on the magnetic microwires embedded directly in the conveyor belts mean a significant improvement of the manufacturing and operation of the conveyor belts

Riadenie komplexného elektro-mechanického systému

Elektro-mechanické servopohony sa používajú ako v klasickom letectve, tak aj pri riadení modelov lietadiel pri ovládaní riadiacich plôch, alebo ako pohony pre kamerové plošiny. Dopravné oneskorenie je nepriaznivý fakt, s ktorým je nutné počítať pri využití väčšiny pohonov v priemysle Pri návrhu regulačných obvodov, prítomné dopravné oneskorenie sťažuje regulačný proces a mnohokrát ani neumožňuje využiť klasické PID regulátory navrhnuté bežnými metódami. Článok sa zaoberá a bližšie opisuje návrh otvoreného a spätno-väzobného regulačného obvodu pre kompenzáciu dopravného oneskorenia modelárskeho servopohonu použitého pre stabilizáciu kamerovej plošiny na bezposádkovom dopravnom prostriedku (UAV-Unmanned Aerial Vehicle).Electro-mechanical servoactuators are widely used not only in the classical aviation but also in the area of small unmanned aerial vehicles. They are commonly used for actuation of control surfaces or in stabilized camera gimbals. A transport delay is a negative effect present in most actuators, and it needs to be taken into account. In the process of control algorithm design, the transport delay makes regulation more complicated and many times makes it impossible to use PID controllers designed with basic methods. This article deals with the design of open-loop and closed-loop control algorithms intended for the modeler servoactuator’s transport delay compensation used for unmanned aerial vehicles’ (UAV) camera gimbal stabilization

Rolling Contact Fatigue Life Evaluation Using Weibull Distribution

International audienceSurfaces subjected to rolling and sliding contacts may suffer from contact fatigue. This text deals with solid mechanic aspects of contact fatigue including the description of experimental study on contact fatigue. This document describes the methodology used in MS Excel for evaluation of component survival probability by Weibull distribution in application for evaluation of contact fatigue survival probability. Introduction. Contact stresses and deformations are those that have their origin in the mutual contact of objects, realized by tiny contact areas. Principles of the contact mechanics can be applied for example for calculation of contact stresses between teeth of gear sets, within roller bearings, between the wheel and a rail of rail vehicles, etc. When two solid bodies are brought into a contact, the deformation occurs at or very close to the areas of the true contact, so we have to consider that the stress is three-dimensional. The Hertzian contact stresses (pressures) have a local character and that is the reason why their values, together with the distance from the contact area, decrease rapidly. Stresses that occur, when solving contact tasks, cannot be considered as the linear function of loads, because with the change of the load power, dimensions of the contact area are also different [1]. In the reliability engineering, failure analysis and survival analysis many statistical methodologies are used. In the article measured data were analysed using the Weibull distribution that is a continuous probability distribution, the gradients of which directly inform us about the shape and scale parameters corresponding to the characteristic life and failure rate of the specimen. Methodology for the Weibull distribution calculation in the commonly used MS Excel environment is also described