A Technical Study of Hole Drilling in Ceramics/FRP Laminate Composite Components

2010 ◽  
Vol 97-101 ◽  
pp. 1965-1970 ◽  
Author(s):  
Zheng Lei ◽  
Wei Min Zuo ◽  
Bao Fu Feng ◽  
Jun Tan Yuan

Drilling process of the ceramic composite component (ceramics/FRP/aluminum alloy), as an example of similar ceramics/FRP laminate composite components, was studied intensively. According to the diverse machining properties of the composing materials of ceramic composite components, the special thinwall diamond core bit was developed, with copper based matrix of complex alloy and hot pressing process. Through machining competitive experiments, the feeding mode with constant pressure was determined. After analyzing the diverse hole defects, the process equipment with compressive pre stress was introduced to improve the hole drilling quality, with good validity proved theoretically by the finite element analysis and on this condition, water can be used as the coolant. The process technology presented in this paper can be used for hole drilling in similar composite components made of the same composing materials.

2011 ◽  
Vol 291-294 ◽  
pp. 1952-1956 ◽  
Author(s):  
Xue Liang Bi ◽  
Jian Wang ◽  
Zhan Lin Wang ◽  
Shi Hui Sun

In the drilling process, axial vibration, transverse vibration and torsional vibration happen to drilling string. And the coupled vibration is more complex. In the resonance state, drilling string collides with the wall, which causes serious damage on drilling string in a short time and results in economic loss to the drilling operation. In this paper, the regularity of coupled vibration is analyzed by using finite element method. The model of full-hole drilling strings is established. The distribution regularities of coupled resonant frequency are obtained through computer analysis. The coupled model is more accurate than single vibration model. And the gaps of high rotary speed resonance regions are larger. Resonance state can be avoided by changing rotary speed, and drilling accidents can be reduced.


2021 ◽  
Vol 271 ◽  
pp. 01004
Author(s):  
Weizheng Wu

Due to the low firmness coefficient of soft coal seam and the influence of formation pressure and in-situ stress, it is easy to cause hole collapse in bedding drilling, resulting in low hole forming rate and insufficient hole forming depth, so the drilling technology needs to be improved. This paper focuses on the study of hole forming technology and parameters of bedding drilling in soft coal seam. The research results show that: the key to improve the construction efficiency of bedding drilling in soft coal seam is to improve the slag removal ability of drilling engineering, and the drilling technology of spiral drilling and pressure air slag removal is conducive to improve the drilling depth and drilling effect. The hole forming process and parameters of spiral drilling and pressure air slag removal are systematically described. The drill pipe speed, the coal conveying capacity in the hole, the minimum wind speed of pressure air slag removal and the air supply pressure of slag removal are determined. It is of great practical significance to develop and improve the drilling technology of bedding hole drilling in soft coal seam to improve the gas drainage capacity of coal mine and the drilling depth and rate of bedding hole drilling in soft coal seam.


2012 ◽  
Vol 531 ◽  
pp. 566-570 ◽  
Author(s):  
Quan Sun ◽  
Bo Gao ◽  
Chong Chang Yang ◽  
Bing Bing Chen

In order to better understand the micro-hole cutting processes in stainless steel, the cutting process of 1Cr18Ni9Ti stainless steel was modeled and simulated by FEA (Finite Element Analysis) based on DEFORM-3D software. The influence of rotation speed and feed speed on the thrust force and torque of 1Cr18Ni9Ti stainless steel were analyzed. Meanwhile, the comparisons of simulated results and theoretical calculation results were taken into consideration. It is found that the simulation data from DEFORM-3D agreed well with the theoretical calculation results. It confirms that the results of simulation based on DEFORM-3D have a high level of reliability. The findings of the present study provide a new way to systematically investigate the stainless steel micro-hole drilling process.


2019 ◽  
Vol 3 (2) ◽  
pp. 111-118
Author(s):  
Bahtiar Wilantara ◽  
Raharjo Raharjo

This study aims to develop an analog compression tester measuring instrument into a digital compression tester as a measurement tool that can provide effectiveness and efficiency to users.                     This research is a research and development or R&D. This research was conducted in several steps, namely: problem identification, information gathering, product design, product manufacture, expert validation, product revision, testing, final production. The development of analog compression tester was first validated by material experts, media experts, and 15 students, and 5 students for field trials. The subjects of this study were vocational students at Taman Karya Madya Teknik Kebumen. Data collection techniques used in this study using instruments in the form of a questionnaire. The data analysis technique of this research is descriptive qualitative and quantitative descriptive percentage.                 The results of the development of digital compression tester designs are: 1) the tools and materials used are electric drill, grinding, cutter, goggles, gloves, masks, ruler, acetaminine welding, screwdriver, scissors, digital dial pressure gauge, hose, spark plugs, clamps , and nepel, 2) the manufacturing process that starts from the cutting process, the hole drilling process, the welding process and the process of connecting between components, 3) the workings of digital compression tester design that is reading the pressure or compression of the machine displayed on the monitor digitally using dial pressure digital gauge, 4) the test results obtained from the validation results from: a) material experts at 89% or Eligible; b) media experts at 85% or reasonable; c) response of field trial students in terms of ease of use and reading of 90% or feasible. Thus, the conclusion that the digital compression tester measuring instrument declared feasible to use for measurement.


Materials ◽  
2021 ◽  
Vol 14 (2) ◽  
pp. 314
Author(s):  
Miroslav Pástor ◽  
Martin Hagara ◽  
Ivan Virgala ◽  
Adam Kaľavský ◽  
Alžbeta Sapietová ◽  
...  

This paper presents a uniquely designed device combining the hole-drilling technique with two optical systems based on the PhotoStress and digital image correlation (DIC) method, where the digital image correlation system moves with the cutting tool. The authors aimed to verify whether the accuracy of the drilled hole according to ASTM E837-13a standard and the positioning accuracy of the device were sufficient to achieve accurate results. The experimental testing was performed on a thin specimen made from strain sensitive coating PS-1D, which allowed comparison of the results obtained by both methods. Although application of the PhotoStress method allows analysis of the strains at the edge of the cut hole, it requires a lot of experimenter’s practical skills to assess the results correctly. On the other hand, the DIC method allows digital processing of the measured data. However, the problem is not only to determine the data at the edge of the hole, the results also significantly depend on the smoothing levels used. The quantitative comparison of the results obtained was performed using finite element analysis.


2020 ◽  
Vol 87 (12) ◽  
pp. 757-767
Author(s):  
Robert Wegert ◽  
Vinzenz Guski ◽  
Hans-Christian Möhring ◽  
Siegfried Schmauder

AbstractThe surface quality and the subsurface properties such as hardness, residual stresses and grain size of a drill hole are dependent on the cutting parameters of the single lip deep hole drilling process and therefore on the thermomechanical as-is state in the cutting zone and in the contact zone between the guide pads and the drill hole surface. In this contribution, the main objectives are the in-process measurement of the thermal as-is state in the subsurface of a drilling hole by means of thermocouples as well as the feed force and drilling torque evaluation. FE simulation results to verify the investigations and to predict the thermomechanical conditions in the cutting zone are presented as well. The work is part of an interdisciplinary research project in the framework of the priority program “Surface Conditioning in Machining Processes” (SPP 2086) of the German Research Foundation (DFG).This contribution provides an overview of the effects of cutting parameters, cooling lubrication and including wear on the thermal conditions in the subsurface and mechanical loads during this machining process. At first, a test set up for the in-process temperature measurement will be presented with the execution as well as the analysis of the resulting temperature, feed force and drilling torque during drilling a 42CrMo4 steel. Furthermore, the results of process simulations and the validation of this applied FE approach with measured quantities are presented.


2005 ◽  
Vol 127 (2) ◽  
pp. 271-276 ◽  
Author(s):  
D. N. Dilley ◽  
D. A. Stephenson ◽  
P. V. Bayly ◽  
A. J. Schaut

Drill chatter degrades hole roundness, hole size, and tool life. This wastes time and money in tools, scrap, and hole rework. Chatter prediction in milling and turning has shown significant benefit to industry; however, researchers have been unable to accurately predict chatter in drilling applications. In the past, the drill, including the chisel edge, was modeled as either a fixed-fixed or fixed-pinned beam (Tekinalp, O., and Ulsoy, A. G., 1989, “Modeling and Finite Element Analysis of Drill Bit Vibrations,” ASME J. Eng. Indust. 111, pp. 148–154), but more recent research (Dilley, D. N., Bayly, P. V., and Schaut, A. J., 2005, “Effects of the Chisel Edge on the Chatter Frequency in Drilling,” J. Sound Vib., 281, pp. 423–428) has shown that a fixed-embedded model using springs improves frequency matching. The effects of the drill margins on dynamics have not been studied. The fixed-fixed or fixed-pinned model will be shown to be inappropriate for modeling the effects of margin engagement, while the spring-end boundary condition can better approximate the frequency increase observed experimentally as the drill margins engage deeper into the hole. In addition, the shifted frequency is well below the frequency found from an analytical fixed-fixed or fixed-pinned beam. Evidence that the margins cause the frequency shift is seen in three-dimensional waterfall plots that show this shift for pilot hole drilling (in which the margins are engaged), but not for tube drilling (in which margins are not engaged).


2015 ◽  
Vol 2015 ◽  
pp. 1-11 ◽  
Author(s):  
Qiang Fang ◽  
Ze-Min Pan ◽  
Bing Han ◽  
Shao-Hua Fei ◽  
Guan-Hua Xu ◽  
...  

Drilling carbon fiber reinforced plastics and titanium (CFRP/Ti) stacks is one of the most important activities in aircraft assembly. It is favorable to use different drilling parameters for each layer due to their dissimilar machining properties. However, large aircraft parts with changing profiles lead to variation of thickness along the profiles, which makes it challenging to adapt the cutting parameters for different materials being drilled. This paper proposes a force sensorless method based on cutting force observer for monitoring the thrust force and identifying the drilling material during the drilling process. The cutting force observer, which is the combination of an adaptive disturbance observer and friction force model, is used to estimate the thrust force. An in-process algorithm is developed to monitor the variation of the thrust force for detecting the stack interface between the CFRP and titanium materials. Robotic orbital drilling experiments have been conducted on CFRP/Ti stacks. The estimate error of the cutting force observer was less than 13%, and the stack interface was detected in 0.25 s (or 0.05 mm) before or after the tool transited it. The results show that the proposed method can successfully detect the CFRP/Ti stack interface for the cutting parameters adaptation.


Author(s):  
Aditya Thadani ◽  
Athamaram H. Soni

Abstract Experimental and theoretical research data was utilized in building a Fuzzy Logic Controller model applied to simulate the drilling process of composite materials. The objective is to have a better understanding and control of delamination of composites during the drilling process and at the same time to improve the hole finish by controlling fraying and splintering. By controlling the main issues in the drilling process such as feed rate, cutting speed, thrust force, and torque generated in addition to the tool geometry, it is possible to optimize the drilling process avoiding the conventionally encountered problems.


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