P. Mayuet

Digital Modeling of End-Mill Cutting Tools for FEM Applications from the Active Cutting Contour

A very current technique in the research field of machining by material removal is the use of simulations using the Finite Element Method (FEM). Nevertheless, and although is widely used in processes that allows approximations to orthogonal cutting, such as shaping, is scarcely used in more complexes processes, such as milling. This fact is due principally to the complex geometry of the cutting tools in these processes, and the need to realize the studi es in an oblique cutting configuration. This paper shows a methodology for the geometrical characterization of commercial end-mill cutting tools, by the extraction of the cutting tool contour, making use of optical metrology, and using this geometry to model the active cutting zone with a 3D CAD software. This model is easily exportable to different CAD formats, such as IGES or STEP, and importable from FEM software, where is possible to study the behavior in service of the same ones.

Roughness Based Analysis of the Influence of Tool Coating in the Dry Turning of UNS R56400 Ti Alloy

Light alloys, such as Aluminium or Titanium based alloys are frequently used in the aircraft industry. In the particular case of Ti alloys, they are usually commonly turned for obtaining strategic airships parts under rigorous quality requirements, in order guarantee the functionality of the workpiece design conditions. So, the analysis of the finishing quality of the turned pieces is essential in the quality control process. In this paper a study of the finishing quality of dry turned UNS R56400 Ti alloy has been achieved on the basis of the analysis of workpiece surface roughness, Ra, as a function of cutting parameters, such as feed and cutting speed. In parallel, a comparative analysis of the influence of the tool coating has been achieved. The obtained results have shown that coated tools cause a worse surface finishing quality.

A Single Students' Experience for Visualizing Completely a Semester Subject

Manufacturing Engineering Processes Knowledge Area has developed an innovative teaching experience in order to give, only in one session, a complete view of a basic subject, Manufacturing Engineering. This experience has been developed on the basis of making a cube constructed in card by groups of students. Starting from this, the different steps of a manufacturing process have been identified, as well as the necessity of establishing a quality control for any of them. Moreover, the different material processing technology types have been distinguished, the concept of process performance has been introduced and the different possibilities for sequential and/or parallel processing have been analyzed. On the basis of this, the students have built the topics program of the subject, justifying its competences distribution. In the same way, the students have defined the related basic concepts. At the end of the course, a questionnaire containing the basic cognitive concepts was answered by them, 100% successfully.

Comparison of Diameter and Area Change Based Methods for Evaluating Break-IN and Break-OUT Damages in Dry Drilled Holes of Aeronautical Carbon Fiber Composites

Currently, Carbon Fiber Reinforced Non-Metal Composites (CFRC) are commonly applied in structural components of aircrafts. Frequently, these elements need to be drilled for their assembly in the final product. Chips close to powder are formed when this kind of material is machined. Because of this, drilling processes are mostly performed in absence of cutting fluids. High quality requirements are demanded for holes due to the fact than those elements are placed in key components of the aircrafts. The most relevant defects that can be produced in the dry drilling of CFRC are located in the both tool input and tool output. These defects are known as Break-IN (B-IN) and Break-OUT (B-OUT). This paper reports on the results of a comparative study of different methodologies for evaluating those defects. First of them is based on the analysis of the diameter deviation. Second procedure is based on the damaged area. Both parameters have been measured making use of image analysis techniques. Obtained results have revealed that damaged area based method is more sensitive to hole changes.

Cutting Speed and Feedrate Based Analysis of Cutting Forces in the One Shot Drilling (OSD) of CFRC/Al Hybrid Stacks

Hybrid stacks structures Composite/Metallic Alloy are commonly applied for manufacturing of structural components in different industrial sectors. Particularly, they are increasingly widely used in the aerospace industry because of these materials combine light weight with a high mechanical resistance. This fact helps to increase the load without needing to increment — even diminishing — the energetic consumption. Carbon Fiber Reinforced Composites (CFRC) and light alloys, such as Aluminium or Titanium based alloys, are usually combined for performing those stacks.CFRC/Alloy stacks based airship structural elements commonly require drilling operations for the posterior assembly tasks. However, the machining processes of Non-Metal Matrix Composites (NMMC), and particularly CFRC, show significant differences with the machining processes of metallic materials. Because of this, it is very difficult to find a joint only one of cutting parameters for drilling these structures using One Shot Drilling (OSD) techniques.In this work, a study of the cutting forces developed in the dry-OSD of CFRC/UNS A92024 stacks has been achieved as a function of the cutting speed and feedrate parameters. Dry drilling tests have been performed using different parameters for drilling CFRC and alloy. A change of the parameters in the interface between CFRC and the alloy has been programmed through a CAM software.Higher cutting force values have been observed in the case of the Aluminium alloys. For both materials, obtained results have shown a strong increase of the cutting force with the increase of feedrate. However, only a slight increase with cutting speed has been observed.The evolution of the cutting force as a function of the holes number has shown a trend to increase only for highest feedrates when CFRC/Alloy is drilled. From the obtained results a F(f,v) model has been proposed.Copyright

Design and Development of Integrated Lab-Practical Class in Manufacturing Engineering

University studies have changed in Spain in the last five years in order to adequate them to the European Space for Higher Education. Under these changes Spanish law fixes the skills and abilities that must acquire the Graduates in Engineering with competences and applications in the Industrial Field. Among them, it can be found the corresponding to Manufacturing Engineering. In this work an Integrated Lab-Practical Class has been performed including different stages of a Manufacturing Process from the Product/Process Design to the Final Product. This Practical Class is developed in six sessions. This experience has shown the interest of the students for the contents of the subject and its relationship with the theoretical concepts.

Digital modeling of end-mill cutting tools for FEM applications from the active cutting contour

A very current technique in the research field of machining by material removal is the use of simulations using the Finite Element Method (FEM). Nevertheless, and although is widely used in processes that allows approximations to orthogonal cutting, such as shaping, is scarcely used in more complexes processes, such as milling. This fact is due principally to the complex geometry of the cutting tools in these processes, and the need to realize the studi es in an oblique cutting configuration. This paper shows a methodology for the geometrical characterization of commercial endmill cutting tools, by the extraction of the cutting tool contour, making use of optical metrology, and using this geometry to model the active cutting zone with a 3D CAD software. This model is easily exportable to different CAD formats, such as IGES or STEP, and importable from FEM software, where is possible to study the behavior in service of the same ones.