Grzegorz Budzik

Experimental method of tooth contact analysis (TCA) with rapid prototyping (RP) use

Purpose – The purpose of this paper is to determine the instantaneous contact area in a gearbox using rapid prototyping.Design/methodology/approach – The determination of the contact area utilizes one of the RP techniques, i.e. stereolithography. Stereolithography enables the making of gears with complex profiles, which are difficult to obtain by means of other machining methods. A model of a bevel gearbox with Gleason spiral generated modify roll (Gleason SGM) gears with circular‐arc profiles of teeth is applied as an example for testing. A prototype of the gearbox was made using SLA 250 apparatus.Findings – Correct mating of gears and their kinematical precision depend on the shape and size of the instantaneous contact area, as well as changes during the turning of gears. Contact between gear surfaces of a geometrically ideal gearbox occurs at a point or line, but, because of a deformability of mating flanks teeth, in reality it is always a certain surface. This paper presents research on the instantane...

Rapid prototyping in manufacturing of core models of aircraft engine blades

Purpose – The purpose of this paper is to present the advantages of computer-aided design/rapid prototyping (CAD/RP) usage in designing and manufacturing of the core models used for precise casting with direct and single solidification of aircraft engine turbine blade cores. Design/methodology/approach – The process of modelling three-dimensional CAD geometry of research blade in relation to the model of the core was presented with different wax types used in the RP technique. Findings – The geometry of the blade model has been designed in a way which allows making a silicon mould on the basis of a base prototype in the process of rapid tooling (RP/RT). Filing by different wax types was investigated in mean of the impact on filling accuracy of the mould cavity. Originality/value – The resulting models were used to make ceramic moulds and carry further work on the development of casting technology in the process of directional solidification and single crystal solidification of core blades of aircraft engines.

Defining influence of load conditions on distribution and value of stresses in dual-power-path gear wheels applying FEM

Purpose – The analysis, carried out for this publication, concerned checking the nature of mating of gear wheels with different load conditions. The computation was made applying FEM in Abaqus 6.10-1 program and concerned spur gears in dual-power-path gears made of ABS. The same geometrical models, material parameters and boundary conditions were assumed for all the analysed stages of the computation. However, the values of torque transmitted from active wheels to passive wheel of the gearing were changed. The paper aims to discuss these issues. Design/methodology/approach – Observing changes of stress levels for toothed wheel and pinions allows to state that for relatively low load values, bending stresses at tooth root change proportionally to the change of the applied load. Findings – Values of contact stresses on mating teeth flanks were also defined for the most loaded part of the dual-power-path gearing, namely for a pinion. In case of contact stresses, it was observed that together with constant in...

Manufacturing of aircraft engine transmission gear with SLS (DMLS) method

Purpose The purpose of this paper is to present the methodology for manufacturing of aircraft transmission gears using incremental method of rapid prototyping (RP) – direct metal laser sintering (DMLS). The production of prototypes from metallic powders using described system allows the execution of final elements of complex structures with additional economic impacts. Design/methodology/approach The paper describes the use of selective laser sintering method (DMLS) by EOS Company. Whole chain of production of prototype is presented with the addition of geometric accuracy measurements by blue light laser device. Findings Presented in the research analysis of SLS/SLM technologies as rapid manufacturing systems shows that they can be applied in the production of prototypes used in the manufacturing process of gears for propulsion systems in aviation industry. Also, very important is the geometrical accuracy of gear prototypes produced by incremental methods. It determines subsequent treatment steps for aircraft propulsion system gears. Practical Implications The use of RP techniques as an alternative for conventionally used manufacturing method has mainly an economic impact related to the cost of time-consuming process and amount of defected elements appearing in serial production. Originality/value This paper presents possibility to use RP – DMLS system – for propulsion elements of aircraft structure. This research is original because of the complex description of the whole chain of manufacturing process. Additionally, geometrical accuracy measurement methodology by blue light presented with the RP method of manufacturing gives the research a unique characteristic.

The assessment of geometric accuracy of aircraft engine blades with the use of an optical coordinate scanner

Purpose The purpose of this paper is to present coordinate measuring system possibilities in the meaning of the geometric accuracy assessment of hot zone elements in aircraft engines. The aim of the paper is to prove that this method, which uses blue light and is most sufficient and cost-saving method, can to be used in the production line for serial manufacturing of elements, for which a high level of accuracy is required. Design/methodology/approach The analysis of the geometric accuracy of the blades was performed using non-contact optical coordinate scanner ATOS Triple Scan II Blue Light, manufactured by GOM Company, at the Department of Mechanical Engineering, Rzeszow University of Technology. Geometric analysis was conducted for blades manufactured from different waxes (A7Fr/60 and RealWax VisiJet CPX200), thus comparing injection technique and rapid prototyping (RP) method, and for casting made of Inconel 713C nickel-based superalloy. Findings The analysis of the criteria for the method of blades’ measuring selection showed that the chosen system successfully met all criteria for the verification of blades’ geometry at the selected stages of the process. ATOS II optical scanner with blue light technology allows measurement almost regardless of daylight or artificial (white) light. This allows the application of the measurement system in the production cycle, thus eliminating the need to create special conditions for measurements. Practical implications Requirements related to the accuracy of measured values, diversity and allowable measurement time are linked with the methods of production. Modern manufacturing methods based on computer-aided design systems/manufacturing/engineering systems require a non-contact optical measurement method based on the computer-aided-based coordinate measuring technique. In case of the non-contact optical scanning method based on the ATOS GOM measuring system, time and measurement costs depend on the methodology of measurement and the possibility of its automation. This is why the presented paper has a practical impact on possibilities for the automation of geometric accuracy measurements of obtained elements in the series production line. Social implications The use of ATOS Triple Scan II Blue Light by GOM Company allows the reduction of cost and time of production because of the possibility of the introduction of this system in an automated production line. Additionally, the measurement of hot section blades of aircraft engines by using the blue light method is much more accurate and has implication as it impacts safety of further used manufactured elements. Originality/value This paper presents the possibility of using the ATOS Triple Scan II Blue Light measuring system for geometric accuracy measurements in case of hot section blades of aircraft engines. This research is original because it describes three model geometric accuracy measurements, wax model obtained using the injection technique, wax model obtained using the I RP process and casting made of Inconel 713C nickel-based superalloy.

The influence of change in slice thickness on the accuracy of reconstruction of cranium geometry.

The article presents a comparative study of change in slice thickness on the accuracy of reconstruction of cranium geometry. Research was performed on 10 different patients. Digital Imaging and Communications in Medicine data were obtained on the Siemens Somatom Sensation Open 40 scanner. At the stage of reconstruction, the same parameters were utilized, while only slice thickness was changed. Modeling with voxel dimensions of 0.4 mm × 0.4 mm × 2.4 mm was chosen as the gold standard over the modeling approach comprising voxel dimensions of 0.4 mm × 0.4 mm × 4.8 mm. The influence of layer thickness on the accuracy of cranium geometry is very similar for the 10 presented patients. The average results show a distribution with a positive skew and kurtosis. The value of skewness is 0.284 (small asymmetry) and kurtosis is 3.746 (a distribution more peaked). Based on 95% confidence, the changes in layer thickness from 2.4 to 4.8 mm generated errors reconstructing the geometry of the cranium by 0.516 mm ± 1.345 mm. The presented research highlights new opportunities to control deviations at the stage of data processing and modeling geometry of the cranium.

The Application of Direct Metal Laser Sintering (DMLS) of Titanium Alloy Powder in Fabricating Components of Aircraft Structures

This study presents detailed characteristics of the DMLS method as used for titanium alloy powder with reference to a possible intended use in aeronautics applications.In the present study test models were made, designed for trials in which the model material properties are to be determined and which specify the basic features of the RP/DMLS technique. In order to evaluate the ultimate use of the DMLS technique in fabricating titanium alloy parts, the following procedures were conducted: tensile and upsetting tests for Ti6Al4V alloy samples (a comparative analysis for DMLS models and models fabricated, respectively, from titanium sheet and bar was carried out), an SEM analysis of the microstructure of the fragments of the surface of polished and etched samples, a Vickers hardness test and an analysis of the accuracy of the reproduction of the shape and roughness of the model fabricated in the DMLS procedure. A detailed analysis of the DMLS method significantly supplements the existing body of knowledge on innovative rapid prototyping techniques [1–4], and the results allow us to specify a group of aircraft structure components which may be fabricated using this method. Excellent strength properties of DMLS models and the possibility of improving surface quality by mechanical working enable the fabrication of advanced aircraft structure components operated in target conditions (under load).

Universal test stand for research of aeronautical multi - power path gear demonstrators

Gears used for the tests may be made of metal or plastic [1, 2, 5]. The stand has been designed in an open system and it is powered by a three-phase electric motor. The control is provided by a single-phase inverter with three outputs, which provides full speed control. All components have been installed on a table equipped with T-slots in order to determine the optimal position of the drive and the tested gear. The load of the stand is realized by an electromagnetic powder brake. Load torque of the gear depends on the supplied current. During the test, you can change settings such as speed or load torque. Torque meters installed on input and output of the demonstrator let you control the work of the whole gear. Values supplied by the torque meters (torque and speed) are recorded on a computer in real time (according to PC RTC) and archived by specialized software. The software installed on your computer allows you to view results of the measurements. The possibility to control working time lets you precisely define the time intervals of various stages of the research. Using timer makes it possible to observe the current consumption of the transmission and helps to establish the research process. Thanks to data, recording you will know when the gear is damaged. Tests at this stand allow for obtaining stable working parameters, and thus for obtaining not distorted, accurate results of the demonstrator operation. Changing the gear is exceptionally simple because of the use of sliding splined connections of the couplings. Separating couplings between which the gear is situated and unlocking, the terminal allows exchanging it.

Hybrid method for rapid prototyping of core models of aircraft engine blades

The paper presents the possibility of using CAD/RP for the design and manufacture of the core models used for precise casting of core aircraft engine turbine blades, with directional crystallization process and single crystallization. The process of modelling 3D CAD geometry of research blade in relation to the model of the core was presented. The sample design, blade base model, was made by one of the incremental method of rapid prototyping Jetting System. The geometry of the blade model has been designed in a way, which allows making a silicon form on the basis of a base prototype in the process of rapid prototyping tools (Rapid Tooling). The form allows the attachment of the blade core in a place designed specifically for this purpose. The silicon form has enabled the production of wax models with the inner core. This task was achieved by proper shaping of forms with the plane of its division. The resulting models were used to make ceramic moulds and carry further work on the development of casting technology in the process of directional crystallization and single crystallization of core blades of aircraft engines.

Analysis of 3D printing parameters of gears for hybrid manufacturing

The paper deals with analysis and selection of parameters of rapid prototyping of gears by selective sintering of metal powders. Presented results show wide spectrum of application of RP systems in manufacturing processes of machine elements, basing on analysis of market in term of application of additive manufacturing technology in different sectors of industry. Considerable growth of these methods over the past years can be observed. The characteristic errors of printed model with respect to ideal one for each technique were pointed out. Special attention was paid to the method of preparation of numerical data CAD/STL/RP. Moreover the analysis of manufacturing processes of gear type elements was presented. The tested gears were modeled with different allowances for final machining and made by DMLS. Metallographic analysis and strength tests on prepared specimens were performed. The above mentioned analysis and tests were used to compare the real properties of material with the nominal ones. To improve the quality of surface after sintering the gears were subjected to final machining. The analysis of geometry of gears after hybrid manufacturing method was performed (fig.1). The manufacturing process was defined in a traditional way as well as with the aid of modern manufacturing techniques. Methodology and obtained results can be used for other machine elements than gears and constitutes the general theory of production processes in rapid prototyping methods as well as in designing and implementation of production.The paper deals with analysis and selection of parameters of rapid prototyping of gears by selective sintering of metal powders. Presented results show wide spectrum of application of RP systems in manufacturing processes of machine elements, basing on analysis of market in term of application of additive manufacturing technology in different sectors of industry. Considerable growth of these methods over the past years can be observed. The characteristic errors of printed model with respect to ideal one for each technique were pointed out. Special attention was paid to the method of preparation of numerical data CAD/STL/RP. Moreover the analysis of manufacturing processes of gear type elements was presented. The tested gears were modeled with different allowances for final machining and made by DMLS. Metallographic analysis and strength tests on prepared specimens were performed. The above mentioned analysis and tests were used to compare the real properties of material with the nominal ones. To improve t...