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

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

FEM modeling of magnetic microwire and its using for stress monitoring inside the composite beam

The proposed article is devoted to the stress evaluation inside the composite beam using the embedded magnetic microwire sensors. The interlaminar stresses with high values can occur inside the composite structures during the operation. It is essential to monitor the stresses and to increase the lifetime of the composite materials by prediction using the research results from the stress distribution estimation and also during the operation using the embedded magnetic microwire-based sensors. In the article the results of the mechanical stress distribution between the magnetic microwire coating and core and the discussion about the experimental application of the magnetic microwire inside the composite beam are presented

Numerical and experimental analysis of innovative support system of belt conveyor

The article processes an issue of the strength of a support system of a belt conveyor applying the numerical and experimental analysis approach. The support system of a belt conveyor is during the operation exposed to high impact forces due to the impact of the foreign objects. The methodology of the numerical analysis is based on the finite element modelling and according to the experimental analysis the boundary conditions are estimated. The results obtained using the numerical analyses are identical to the results from the experimental analysis. Maximal damage of the support system of a belt conveyor is estimated and according to the proposed methodology verified by the comparison of the experimental and numerical results, the design and optimization of the support system for the practical operation can be performed

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