Reverse Engineering (RE) involves the use of techniques aimed to retrieve information about manufactured products, not only regarding geometries, but also materials and functionality. Today, even if several RE techniq...Reverse Engineering (RE) involves the use of techniques aimed to retrieve information about manufactured products, not only regarding geometries, but also materials and functionality. Today, even if several RE techniques are known, many of them still leave the object unusable to analyze. Nevertheless, other alternatives to this problem allows for obtaining a Digital or Virtual Model (VM) via the three-dimen- sional scanning. Getting the VM of an item, via scanning or not, can offer many possibilities to digital analysis (FEM). Furthermore, starting from VM, it is possible to achieve the physical reproduction of an element, part or workpiece—in the same or different materials—using Additive Manufacturing (AM) technologies. This enables to improve the product through a redesign process. In this paper, a RE based methodology is proposed for redesigning a tool for contour milling, after comparing different microscopy based techniques, 3D-Scanner tools and CAD-CAGD utilities for generating a Virtual Model of the newly designed mill.展开更多
Commonly, Carbon Fiber Reinforced Plastics (CFRP) aerospace elements need to be machined (drilling) for subsequent assembly operations, mainly riveting, taking a critical importance the quality requirements of the hol...Commonly, Carbon Fiber Reinforced Plastics (CFRP) aerospace elements need to be machined (drilling) for subsequent assembly operations, mainly riveting, taking a critical importance the quality requirements of the holes. Some of the adjustment defects that can be produced during the dry drilling of CFRP are related to macrogeometrical (diameter, D, and cylindricity, DC) deviations. This paper reports on the results of a study of the influence of the cutting parameters V (cutting speed) and f (feedrate) on the D and DC deviations in the dry drilling of CFRP. A particular procedure based on plastic hole replicas has been performed. Diameters deviations were acceptable in all the cases studied. Because of this, DC is the controlling factor for accepting the drilled holes. In the studied range, lowest cutting speeds and highest feedrates have allowed obtaining the minimum cylindricity deviation.展开更多
文摘Reverse Engineering (RE) involves the use of techniques aimed to retrieve information about manufactured products, not only regarding geometries, but also materials and functionality. Today, even if several RE techniques are known, many of them still leave the object unusable to analyze. Nevertheless, other alternatives to this problem allows for obtaining a Digital or Virtual Model (VM) via the three-dimen- sional scanning. Getting the VM of an item, via scanning or not, can offer many possibilities to digital analysis (FEM). Furthermore, starting from VM, it is possible to achieve the physical reproduction of an element, part or workpiece—in the same or different materials—using Additive Manufacturing (AM) technologies. This enables to improve the product through a redesign process. In this paper, a RE based methodology is proposed for redesigning a tool for contour milling, after comparing different microscopy based techniques, 3D-Scanner tools and CAD-CAGD utilities for generating a Virtual Model of the newly designed mill.
文摘Commonly, Carbon Fiber Reinforced Plastics (CFRP) aerospace elements need to be machined (drilling) for subsequent assembly operations, mainly riveting, taking a critical importance the quality requirements of the holes. Some of the adjustment defects that can be produced during the dry drilling of CFRP are related to macrogeometrical (diameter, D, and cylindricity, DC) deviations. This paper reports on the results of a study of the influence of the cutting parameters V (cutting speed) and f (feedrate) on the D and DC deviations in the dry drilling of CFRP. A particular procedure based on plastic hole replicas has been performed. Diameters deviations were acceptable in all the cases studied. Because of this, DC is the controlling factor for accepting the drilled holes. In the studied range, lowest cutting speeds and highest feedrates have allowed obtaining the minimum cylindricity deviation.
