scholarly journals Experimental and theoretical researches of high-speed interaction of thin obstacles with a metal fragment

2019 ◽  
Vol 221 ◽  
pp. 01043
Author(s):  
Svetlana Afanasyeva ◽  
Viktor Burkin ◽  
Aleksey Dyachkovsky ◽  
Alexandr Ishchenko ◽  
Konstantin Rogaev ◽  
...  
Keyword(s):  
Mathematical Modeling ◽  
Titanium Alloy ◽  
Continuum Mechanics ◽  
High Speed ◽  
Interaction Process ◽  
Actual Problem ◽  
Cost Weight ◽  
Ballistic Resistance ◽  
Protective Structures ◽  
Metal Fragment

The development of lightweight protective structures of increased ballistic resistance is not an easy task, since often there are conflicting requirements in terms of cost, weight, thickness, materials availability, processability, etc. To assess the effectiveness of protective structures one should use methods that allow to research the obstacles destruction when collided with high-speed particles. The paper is devoted to the actual problem of studying the ballistic stability of thin barriers made of various protective materials (steel, titanium alloy, ceramics, metal ceramics) when interacting with a metal fragment simulator a spherical steel drummer in the range of interaction speeds of about 2500 m/s. An experimental technique has been developed to study the most important indicators: the depth of a crater in an obstacle, a fragment’s velocity drop when interacting with protection, the obstacle’s and splinter’s fragments scattering in overgraded space. Mathematical modeling was carried out within the framework of continuum mechanics, which adequately describes the interaction process of the drummer and the obstacle under various impact conditions.

Application of the method of mathematical modeling for forecasting channel deformations at the underwater crossing of the main pipeline

2020 ◽  
Vol 10 (6) ◽  
pp. 599-609
Author(s):  
Valery А. Gruzdev ◽  
◽  
Georgy V. Mosolov ◽  
Ekaterina A. Sabayda ◽  
◽  
...  
Keyword(s):  
Mathematical Modeling ◽  
Mathematical Model ◽  
Roughness Coefficient ◽  
Computational Domain ◽  
Channel Deformations ◽  
Geological Surveys ◽  
Kuban River ◽  
The Stability ◽  
Protective Structures

In order to determine the possibility of using the method of mathematical modeling for making long-term forecasts of channel deformations of trunk line underwater crossing (TLUC) through water obstacles, a methodology for performing and analyzing the results of mathematical modeling of channel deformations in the TLUC zone across the Kuban River is considered. Within the framework of the work, the following tasks were solved: 1) the format and composition of the initial data necessary for mathematical modeling were determined; 2) the procedure for assigning the boundaries of the computational domain of the model was considered, the computational domain was broken down into the computational grid, the zoning of the computational domain was performed by the value of the roughness coefficient; 3) the analysis of the results of modeling the water flow was carried out without taking the bottom deformations into account, as well as modeling the bottom deformations, the specifics of the verification and calibration calculations were determined to build a reliable mathematical model; 4) considered the possibility of using the method of mathematical modeling to check the stability of the bottom in the area of TLUC in the presence of man-made dumping or protective structure. It has been established that modeling the flow hydraulics and structure of currents, making short-term forecasts of local high-altitude reshaping of the bottom, determining the tendencies of erosion and accumulation of sediments upstream and downstream of protective structures are applicable for predicting channel deformations in the zone of the TLUC. In all these cases, it is mandatory to have materials from engineering-hydro-meteorological and engineering-geological surveys in an amount sufficient to compile a reliable mathematical model.

scholarly journals Surface Forming Criteria of Ti-6AL-4V Titanium Alloy under Laser Loading

2021 ◽  
Vol 11 (12) ◽  
pp. 5406
Author(s):  
Fei Yin ◽  
Xia Ye ◽  
Hongbing Yao ◽  
Pengyu Wei ◽  
Xumei Wang ◽  
...  
Keyword(s):  
Titanium Alloy ◽  
Surface Morphology ◽  
High Speed ◽  
Yttrium Aluminum Garnet ◽  
Laser Energy ◽  
Target Material ◽  
Nanosecond Laser ◽  
Laser Shock ◽  
Shock Condition ◽  
Key Factor

In order to study the spallation phenomenon of titanium alloy under the shock of nanosecond laser, the Neodymium-Yttrium-Aluminum Garnet laser was used to carry out laser shock experiments on the surface of titanium alloy. By observing and measuring the surface morphology of the target material, the forming factors and the changes of the surface morphology under different parameter settings, the forming criteria of the titanium alloy were obtained. The results show that under the single variable method, the change of laser energy can affect the target shape variable, and there is a positive correlation between them. When the thickness was greater than or equal to 0.08 mm, no obvious cracks were found in the targets. Moreover, the number of impact times was the key factor for the target deformation; with the growth of impact times, the target deformation gradually became larger until the crack appeared. The larger the diameter of the spot, the more likely the target was to undergo plastic deformation. The surface of titanium alloy with a thickness of 0.08 mm appeared to rebound under specific laser shock condition. The changes in the back of the target material were observed in real time through a high-speed camera, and the plasma induced by the laser was observed in the process. This study is based on the results of previous studies to obtain the titanium alloy forming criteria, which provides a basis for the setting of laser parameters and the thickness of the target when the nanosecond laser impacts the Ti-6AL-4V target.

Removal Mechanism of Titanium Alloy Ti6Al4V Based on Single-Grain High Speed Grinding Test

2011 ◽  
Vol 487 ◽  
pp. 39-43 ◽  
Author(s):  
L. Tian ◽  
Yu Can Fu ◽  
W.F. Ding ◽  
Jiu Hua Xu ◽  
H.H. Su
Keyword(s):  
Titanium Alloy ◽  
High Speed ◽  
Chip Thickness ◽  
Wheel Speed ◽  
High Speed Grinding ◽  
Tc4 Alloy ◽  
Grinding Mechanism ◽  
Single Grain ◽  
On Chip ◽  
Titanium Alloy Ti6al4v

Single-grain grinding test plays an important part in studying the high speed grinding mechanism of materials. In this paper, a new method and experiment system for high speed grinding test with single CBN grain are presented. In order to study the high speed grinding mechanism of TC4 alloy, the chips and grooves were obtained under different wheel speed and corresponding maximum undeformed chip thickness. Results showed that the effects of wheel speed and chip thickness on chip formation become obvious. The chips were characterized by crack and segment band feature like the cutting segmented chips of titanium alloy Ti6Al4V.

Experimental investigation of top burr formation in high-speed micro-end milling of titanium alloy

2018 ◽  
Vol 22 (6) ◽  
pp. 989-1011 ◽  
Author(s):  
Chakradhar Bandapalli ◽  
Kundan Kumar Singh ◽  
Bharatkumar Mohanbhai Sutaria ◽  
Dhananjay Vishnuprasad Bhatt
Keyword(s):  
Experimental Investigation ◽  
Titanium Alloy ◽  
High Speed ◽  
End Milling ◽  
Burr Formation ◽  
Micro End Milling

scholarly journals Experimental study on machining deformation of large scale slender beam with weak stiffness  of Ti6Al4V

2021 ◽  
Author(s):  
Qimeng Liu ◽  
Jinkai Xu ◽  
Huadong Yu
Keyword(s):  
Titanium Alloy ◽  
Tool Wear ◽  
High Speed ◽  
Large Scale ◽  
Machining Accuracy ◽  
Beam Structure ◽  
High Speed Milling ◽  
Deformation Problem ◽  
Machining Deformation ◽  
Slender Beams

Abstract Large-scale slender beam structures with weak stiffness are widely used in the aviation field. There will be a great deformation problem in machining because the overall stiffness of slender beam parts is lower. Firstly, the cutting mechanism and stability theory of the Ti6Al4V material are analyzed, and then the auxiliary support is carried out according to the machining characteristics of the slender beam structure. The feasibility of the deformation suppression measures for the slender beam is verified by experiments. The experimental analysis shows that on the basis of fulcrum auxiliary support, the filling of paraffin melt material is capable of increasing the damping of the whole system, improving the overall stiffness of the machining system, and inhibiting the chatter effect of machining. This method is effective to greatly improve the accuracy and efficiency during machining of slender beam parts. On the premise of the method of processing support with the combination of fulcrum and paraffin, if the tool wear is effectively controlled, the high precision machining of large-scale slender beams can be realized effectively, and the machining deformation of slender beams can be reduced. Although high speed milling has excellent machining effect on the machining accuracy of titanium alloy materials, severe tool wear is observed during high-speed milling of titanium alloy materials. Therefore, high-speed milling of titanium alloy slender beam is suitable to be carried out in the finishing process, which can effectively control tool wear and improve the machining accuracy of parts. Finally, the process verification of typical weak stiffness slender beam skeleton parts is carried out. Through the theoretical and technical support of the experimental scheme, the machining of large-scale slender beam structure parts with weak stiffness is realized.

scholarly journals Кинетика структуры титанового сплава при высокоскоростном проникании ударника

2020 ◽  
Vol 62 (11) ◽  
pp. 1769
Author(s):  
С.А. Атрошенко ◽  
А.Ю. Григорьев ◽  
Г.Г. Савенков
Keyword(s):  
Plastic Deformation ◽  
Titanium Alloy ◽  
High Speed ◽  
Deformation And Fracture ◽  
Mechanisms Of Plastic Deformation

Abstract. The article is devoted to the study of the behavior of a titanium alloy under conditions of high-speed penetration at a speed of approximately 2.0 km / s. It is shown that in the target during penetration, three penetration zones are observed that differ in the mechanisms of plastic deformation and fracture.

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