Andrzej Wróbel

Study of mechanical properties and computer simulation of composite materials reinforced by metal

In the article, two methods for testing of composite materials reinforced by sheet metal were presented. The first method is based on computer simulation of stresses in the investigated objects. It was carried out in the graphical programme NX. The second method consists in measuring deformations using strain gauge bridges and comparative analysis was carried out. The obtained results show that both methods were applied correctly and the error reaches a few percent.

Computer-aided strength analysis of the modernized freight wagon

In the paper results of computer-aided strength analysis of the modernized freight wagon based on Finite Element Method are presented. CAD model of the considered freight wagon was created and its strength was analysed in agreement with norms described the way of such kind of freight wagons testing. Then, the model of the analysed freight wagon was modernized by adding composite panels covering the inner surface of the vehicle body. Strength analysis was carried out once again and obtained results were juxtaposed. This work was carried out in order to verify the influence of composite panels on the strength of the freight car body and to estimate the possibility of reducing the steel shell thickness of the box in order to reduce weight of the freight wagon.

Designing of robotic production lines using CAx software

Present market conditions causes that modern control systems of robotized manufacturing cells should be characterized by the much greater degree of flexibility, selforganization and, above all, adaptability to emerging outer excitations. The phenomenon of information distribution is one of the most important features of modern control systems. In the paper is presented the approach, based on application of multi-agent systems, for supporting the operation of robotized manufacturing cells. The aim of this approach is to obtain the flexible response to outer excitations and preventing situations that might cause the delay of the production process. The presented paper includes description of the concept of an informatics system designed for controlling the work of production systems, including work cells. Such systems could operate independently if it would be equipped with the selforganization mechanism. It is possible in the case of the proposed multi-agent system. The implementation of the presented concept will follow the present analysis of the described concept. The advantage of the proposed concept is its hierarchical depiction that allows integrating different utilized informatics tools in one complex system. It allows preparing the final computer program.

Analysis of possibility of applying the PVDF foil in industrial vibration sensors

There are many machines using the piezoelectric effects. Systems with smart materials are often used because they have high potential applications for example transducers can be applied to receive required characteristic of projected system. Every engineer and designer know how important it is properly mathematical model and method of the analysis. Also it is important to consider all parameters of analyzed system for example glue layer between elements. Geometrical and material parameters has a significant impact on the characteristics of the all systems components because the omission of the influence of one of them results in inaccuracy in the analysis of the system. In article the modeling and testing of vibrating systems with piezoelectric ceramic materials transducers used as actuators and vibration dampers. The method of analysis of the vibrating sensor systems will be presented, mathematical model, and characteristics, to determine the influence of the systems properties on these characteristics. Main scientific point of the project is to analyze and demonstrate possibility of applying new construction with the PVDF foil or any other belonging to a group of smart materials in industrial sensors. Currently, the vibration level sensors are used by practically all manufacturers of piezoelectric ceramic plates to generate and detect the vibration of the fork.

An Endurance Test of Composite Panels

In this paper possibilities of freight wagons modernization using new composite materials was presented. This work was carried out under the project number PBS2/A6/17/2013 agreement implemented under the Applied Research Program, founded by the National Centre for Research and Development. All of this activities are done as consortium consists of the scientific entity – the Institute of Engineering Processes Automation and Integrated Manufacturing Systems of the Silesian University of Technology and DB Schenker Rail Poland SA and Germaz. The purpose of this article is analyse the work strength of the connection sheet metal and composite glass-epoxy with multi-point pressure. To estimate the strength of strain-gauge methods were used. The study was conducted on a stand equipped with 4 pneumatic actuators and the PLC. During the tests the same steal plate, then on a plate with mounted rivets and connection steal and composite panel were checked. Some aspects have already been presented in previous publications of the authors. This article is an extension of the previous publications with new knowledge. To determine the changes in the samples strain gauges was used. In the article original program written to the PLC in order to automatically generate pressure on the tested composites was presented. A composite material is a material having a heterogeneous structure composed of two or more components with different properties. structural components most commonly used are fibers such as glass fibers, carbon fibers and Kevlar. Currently, composites are widely used, among others, in construction, aviation, in transprcie, automotive and machinery manufacturing. In this paper research methods for detection of laminate panels damage were presented. Aspect of continuous monitoring of the technical state of the laminate is very important. As part of the work method of endurance test panels made of composite by strain gauge will be presented. In paper machine designed to periodically generate extortion will be also presented. At the Faculty of Mechanical Engineering Technical University of Silesia are conducted research on the analysis and synthesis of mechanical systems and mechatronics concern both theoretical considerations [10,11] how practical industrial tasks Recent works undertaken relate to research the properties of composite materials [1-4, 12-17] as components and assemblies railway wagons [5,8,11]. Some of the work is conducted in collaboration with other research centers [5-9].

Structural Tests of Freight Wagons on the Basis of Signals Generated By Piezoelectric Macro Fiber Composites

Abstract Paper presents a report of a research work that concerns possibilities of freight wagons modernization using new composite materials. The main aim of presented work was to verify the possibility of inference from the dynamic response of the wagon about the changes in its technical condition. During the presented works tests on real objects were carried out using Macro Fiber Composite (MFC) piezoelectric transducers glued to the freight wagon’s frame. The dynamical response of the wagon was measured while the object was driving. On the next stage the measured signal was generated on a laboratory stand using electrodynamic modal shaker and vibrations of the laboratory model were measured. Measured signals were juxtaposed on charts and analysed. The aim of this work was to verify if it is possible to detect the change in the system using measurements of vibrations that are being generated during exploitation of the freight wagon.

Testing of composite panels used as components of a freight wagon by thermovision

Abstract In this paper research methods for detection of laminate panels damage were presented. The most common damage is: matrix cracking laminate interlayer damage to joints, connecting cracks, delamination and fiber breakage. The tested laminates will be used as assemblies and sub-assemblies of freight wagon. Other methods of modeling of machines by means of transducers are shown in Płaczek (2012, 2015) and Białas (2010). As part of the project authors were collaborated with specialists from other research centers and scientific research (Bocian and Kulisiewicz, 2013). As a part of future work the places where we will be able to replace the standard materials by parts made of laminate will be shown. Layered composites despite many advantages have also disadvantages. From last mentioned it is a relatively low resistance to transverse impact. When the laminate is used as a decorative element, its small damage is not a problem. The problems start when the composite satisfies more responsible tasks such as: is a part of the technical means for example of a railway wagon. Aspect of continuous monitoring of the technical state of the laminate is very important. Current technology provides numerous opportunities for non-destructive methods of technical inspections. In this paper method for testing of large areas, completely non-contact, based on the methods of thermography, was presented. It consists heating by using the composite tubes and examining it through a thermal imaging camera. Length of heating, and consequently the temperature to which the laminate is heated mostly were chosen experimentally. During the measurements, the camera measures the intensity of radiation, not temperature. Received thermogram is not always a precise representation of the actual temperature, because the camera does not reach only the radiation from tested object, but also reaches the radiation coming from the environment and reflected objects etc. As part of the research authors also we undertook other work related to Mechanical Engineering (Wróbel et al., 2008, 2010, 2012, 2013, 2015; Płaczek et al., 2014). Cooperation with other national and European centers has contributed to many publications of authors for example Tuma et al. (2013, 2014) and Jamroziak and Kosobudzki (2014).

Application of Piezoelectric Films for Measuring Dynamical Response of Freight Wagons During Exploitation

This paper contains a report on the research of possibilities of the use of piezoelectric transducers in the form of composite films Macro Fiber Composite (MFC) to measure the dynamic response of freight wagons type EAOS during operation. The aim of the study is to verify the possibility to develop a system of supervision of the technical condition of freight wagons, based on measurements of their dynamic response to the standard forces generated during their operation. It was assumed that the MFC piezoelectric films, due to a number of advantages can be used as sensors in the proposed measurement system and to verify the effectiveness of their operation the sequence of tests on real objects during observed rides were carried out. The repeatability of received waveforms of electric voltage, generated by the piezoelectric transducers glued on selected items of wagon stand was verified. In addition, a preliminary analysis of the received signals was done in order to determine their usefulness in the system of supervision of the technical condition of freight cars.

Determining the Response of Piezoelectric Sensors Working as Sensors of Freight Wagon Construction

The presented work is a part of project carried out by the consortium that consists of the scientific entity—the Institute of Engineering Processes Automation and Integrated Manufacturing Systems from the Silesian University of Technology and enterprises—DB Schenker Rail Poland. The aim of this research project is to modernize the analysed wagon during its renovation using new materials (Baier A et al, Experimental synthesis and analysis of geometric and structural properties of chosen elements of railway wagons, 2012, [1]; Placzek M et al, Computer-aided strength analysis of the modernized freight wagon, 2015 [11]; Wrobel A et al, Int J Mater Prod Technol, 50/3–4 (2015) 259–275 [14]). The main objective of project is modernize of the wagon during its renovation using new innovative composites in order to protect sheathing of the wagon against corrosion. This paper contains a report on the research of piezoelectric sensor system. The assumption of the study was to prove that it is possible to continuously monitoring the state of the shell of a freight wagon during driving. All project was divided into several stages: the execution of composite panels as plating freight wagon, installation of piezoelectric sensors in the panels and in the supporting structure of the wagon, design telemetric system which allows the location of the car and collects information from the sensors and the analysis of the received data.

The Mathematical Algorithm for Analysis of Piezoelectric Stacks with Structural Damping

The work presents a proposal of mathematical algorithm developed for analysis of piezoelectric stacks that consist of classical PZT piezoelectric transducers. The considered systems vibrate longitudinally. Piezoelectric plates are combined in order to obtain multiplied displacement of the system and ensure more effective operation. Using constitutive equations of piezoelectric materials and an equation of the single plate’s motion, a matrix of characteristics of the system was obtained. The matrix of characteristics consists of relations between mechanical and electrical parameters (forces, displacements, electric current and voltage) that describe behaviour of the system. A structural damping of the plate’s material was being taken into consideration using Kelvin-Voigt model of material and its influence on the plate’s dynamic flexibility was analyzed [1, 2]. A dynamic flexibility – relation between the plate’s deformation and a force applied to the system is considered. Using the obtained dependences and non-classical methods, characteristics of piezoelectric stacks were designated and presented on charts. The obtained results were juxtaposed with characteristics of the system without structural damping.