Papers by Keyword: High-Speed Video Camera

Abstract: This work develops a methodology that allowed students to associate the effect of some cutting variables with chip type. For that, turning processes were carried out on two different materials since their physical and mechanical properties have a relevant influence on the chip formation. Cutting tests were run by varying the feed rate, while cutting speed and depth of cut had fixed values. These cutting conditions led to different chip geometries being obtained. Thus, it was possible to establish a chip type classification in turning operations. The methodology herein presented is based on new technologies, which raised great expectations among students, who positively considered this experience. The effect of other variables, apart from feed rate, must be theoretically analyzed in order to improve the comprenhension of the process herein involved.

Abstract: The stress and motion state of droplet in MIG welding with alternating longitudinal magnetic field were analyzed, and the impact of alternating longitudinal magnetic field on the droplet transfer were studied by high-speed video camera. The results show that the droplet is spherical approximately and transfer to molten pool along the welding wire axis without external longitudinal magnetic field. When alternating longitudinal magnetic field was introduced into welding process, the droplet rotate around the welding wire clockwise and counter-clockwise alternately. Shape of droplet became flat and direction of transfer deviated from the welding wire axis under the action of magnetic field. As the exciting current increased, extent of deviation from the wire axis increases. When the exciting current is too large (I >20A), extent of deviation is too large and droplet are disintegrated into several small droplet during the transition. So droplet can not transfer into molten pool successfully and the bead can’t be formed.

Abstract: In this paper, orthogonal cutting tests of alloy steel, aluminum alloy and Ti6Al4V have been carried out to consider the cutting mechanism from the viewpoint of friction between the tool and workpiece. The cutting processes were observed in detail using a high-speed video camera. The cutting process of alloy steel was greatly affected by its tribological properties compared with those of the other two work materials. In the cutting process of alloy steel, there were three stages in relation to the state of the tool rake face and temperature. The difference between non coated and coated tools was marked in the later stages. From the discussion on the experimental results, it is considered that the thrust force is suitable for representing the tribological properties between the tool and workpiece. It is concluded that the orthogonal cutting test is a good method for evaluating tribological properties between the tool and workpiece.

Abstract: This paper presents the design of a compact size projectile accelerator, and its application. To meet the various needs such as a compact body size to use under various experimental conditions, an easy maintenance for repetitive experiments during a certain period, and a capability of the velocity control, the compact accelerators were newly designed with a direct explosive drive method. Two different types of accelerator were designed: a PMMA accelerator and a metal accelerator. The pictures of the projectile shoot using the designed accelerators were recorded by SHIMADZU HyperVision HPV-1 high-speed video camera. As a result, it was recognized that the PMMA accelerator was failed to accelerate the projectile, while the metal accelerator succeeded to accelerate it effectively. The accelerating performance of the metal accelerator was further investigated. The explosives for projectile acceleration were Emulsion explosive and Composition C4 explosive weighing 5 to 35g. It was found that the metal accelerator has the capability to control the projectile velocity adjusting the weight of the explosives, and there is an approximate linear correlation between them in our experimental range. A series of impact tests on 5052S aluminum alloy targets was examined using the accelerator.