scholarly journals Hole Making in Gamma Tial

Author(s):  
A. Beranoagirre ◽  
D. Olvera ◽  
G. Urbicain ◽  
L. N. Lopez de Lacalle ◽  
A. Lamikiz
Keyword(s):  
2020 ◽  
Vol 103 (4) ◽  
pp. 003685042098121
Author(s):  
Ying Zhang ◽  
Hongchang Ding ◽  
Changfu Zhao ◽  
Yigen Zhou ◽  
Guohua Cao

In aircraft manufacturing, the vertical accuracy of connection holes is important indicator of the quality of holes making. Aircraft products have high requirements for the vertical accuracy of holes positions. When drilling and riveting are performed by an automatic robotic system, assembly errors, bumps, offsets and other adverse conditions, can affects the accuracy of manufacturing and detection, and in turn the fatigue performance of the entire structure. To solve this problem, we proposed a technology for detecting the normal-direction based on the adaptive alignment method, built a mathematical model for posture alignment, and studied the calibration method and mechanism of the detection device. Additionally, we investigated techniques for error compensation using an electronic theodolite and other devices when the adaptive method is used for detection. In verification experiments of the method, multiple sets of results demonstrated that the key technical indicators are as follows: normal accuracy <0.5°, average deviation after correction =0.0667°. This method can effectively compensate the errors affecting hole making work in automated manufacturing, and further improve the positioning accuracy and normal-direction detection accuracy of the robot.


Author(s):  
Xuda Qin ◽  
Xingfeng Cao ◽  
Hao Li ◽  
Meng Zhou ◽  
Ende Ge ◽  
...  

Due to good aerodynamic performance and reliability, countersunk bolt joint is one of the most commonly used connection methods for carbon fiber reinforced polymer (CFRP) components in the aircraft. However, the countersunk hole machining process is inevitably accompanied by geometric errors, which will directly affect the mechanical properties of the joint structure. This paper presents a numerical and experimental investigation on the effect of countersunk hole geometry errors on the fatigue performance of CFRP bolted joints. FE model of CFRP countersunk bolted joints with designed geometry errors are established, and the rationality of the FE analysis was verified by fatigue life and failure forms. The CFRP bolted structure failure mechanism under fatigue load and influence of hole-making geometry error (including countersunk fillets radius, countersunk depth, and countersunk angle) on the fatigue life are investigated. Based on the relationship between fatigue life and the geometry error, the corresponding tolerances for CFRP bolt joint countersunk hole are determined as well. The research results can provide a reference for establishing reasonable geometric accuracy requirements for CFRP joint hole machining.


2021 ◽  
Author(s):  
Rahmat Ashari ◽  
Owen Sorensen ◽  
Pradeepkumar Ashok ◽  
Eric van Oort ◽  
Matthew Isbell ◽  
...  

Abstract Although numerous studies have investigated how shocks and vibrations contribute to bottomhole assembly (BHA) failures during hole-making, very few have explicitly focused on shock and vibrational behaviors during drillpipe connections. This study adopts a data-driven approach to explore various connection practices and their associated shocks and vibrations, aiming to propose optimum "connection recipes" that minimize negative drillstring impacts during connections. This study utilized data from surface sensors as well as downhole accelerometers and gyroscopes installed both at a downhole sub and the bit. In total, 520 connections from 5 lateral sections were studied. Several quality checks and corrections were performed to ensure synchronization between surface and downhole data. The analyses focused on two connection phases specifically: going off-bottom and going back to bottom. The presence of stick-slip events and high magnitudes of both maximum and root mean squared (RMS) radial accelerations were examined together with the associated surface drilling parameters. Various visualization approaches were performed to help demonstrate the vibration and shock behaviors resulting from different going off-bottom and going back to bottom practices. The analyses showed that restarting surface rotational speed at low values (≤ 40 RPM) risks inducing stick-slip events when going back to bottom. When the surface RPM was increased sufficiently, a notable reduction in RMS radial acceleration was observed. Maximum radial acceleration magnitude was highest before WOB application, which could be mitigated by immediate WOB re-application. Appreciable variation in the maximum radial acceleration was apparent when restarting at low (≤ 15 klbf) WOB values. When going off-bottom, drilling off should be accompanied by a reduction in the surface rotational speed to avoid a jump in the maximum radial acceleration values. This work provides suggestions on how to execute better connections. Since the impacts of shocks and vibrations during connections have previously been largely overlooked, this study fills a knowledge gap to help establish better practices and automation routines to improve the lifespan of the bit and downhole tools.


Author(s):  
Palamandadige K. S. C. Fernando ◽  
Meng (Peter) Zhang ◽  
Zhijian Pei ◽  
Weilong Cong

Aerospace, automotive and sporting goods manufacturing industries have more interest on carbon fiber reinforced plastics due to its superior properties, such as lower density than aluminum; higher strength than high-strength metals; higher stiffness than titanium etc. Rotary ultrasonic machining is a hybrid machining process that combines the material removal mechanisms of diamond abrasive grinding and ultrasonic machining. Hole-making is the most common machining operation done on carbon fiber reinforced plastics, where delamination is a major issue. Delamination reduces structural integrity and increases assembly tolerance, which leads to rejection of a part or a component. Comparatively, rotary ultrasonic machining has been successfully applied to hole-making in carbon fiber reinforced plastics. As reported in the literature, rotary ultrasonic machining is superior to twist drilling of carbon fiber reinforced plastics in six aspects: cutting force, torque, surface roughness, delamination, tool life, and material removal rate. This paper investigates the effects of tool end angle on delamination in rotary ultrasonic machining of carbon fiber reinforced plastics. Several investigators have cited thrust force as a major cause for delamination. Eventhogh, it is found on this investigation, tool end angle has more significant influence on the delamination in rotary ultrasonic machining of carbon fiber reinforced plastics comparing to cutting force and torque.


Author(s):  
Min Wan ◽  
Zekai Murat Kilic ◽  
Yusuf Altintas

The mechanics and dynamics of the combined processes are presented for multifunctional tools, which can drill, bore, and chamfer holes in one operation. The oblique cutting forces on each cutting edge with varying geometry are modeled first, followed by their transformations to tangential, radial, and axial directions of the cutter. The regenerative effect of lateral and torsional/axial vibrations is considered in predicting the dynamic chip thickness with multiple delays due to distribution of cutting edges on the cutter body. The lateral and torsional/axial chatter stability of the complete hole making operation is predicted in semidiscrete time domain. The proposed static cutting force and chatter stability prediction models are experimentally proven for two different multifunctional tools in drilling Aluminum Al7050 and Steel AISI1045.


2018 ◽  
Vol 15 (2) ◽  
pp. 294-301
Author(s):  
Reddy Sreenivasulu ◽  
Chalamalasetti SrinivasaRao

Drilling is a hole making process on machine components at the time of assembly work, which are identify everywhere. In precise applications, quality and accuracy play a wide role. Nowadays’ industries suffer due to the cost incurred during deburring, especially in precise assemblies such as aerospace/aircraft body structures, marine works and automobile industries. Burrs produced during drilling causes dimensional errors, jamming of parts and misalignment. Therefore, deburring operation after drilling is often required. Now, reducing burr size is a serious topic. In this study experiments are conducted by choosing various input parameters selected from previous researchers. The effect of alteration of drill geometry on thrust force and burr size of drilled hole was investigated by the Taguchi design of experiments and found an optimum combination of the most significant input parameters from ANOVA to get optimum reduction in terms of burr size by design expert software. Drill thrust influences more on burr size. The clearance angle of the drill bit causes variation in thrust. The burr height is observed in this study.  These output results are compared with the neural network software @easy NN plus. Finally, it is concluded that by increasing the number of nodes the computational cost increases and the error in nueral network decreases. Good agreement was shown between the predictive model results and the experimental responses.  


2013 ◽  
Vol 69 (1-4) ◽  
pp. 753-769 ◽  
Author(s):  
Xiaojun Liu ◽  
Yi Hong ◽  
Ni Zhonghua ◽  
Qi Jianchang ◽  
Qiu Xiaoli

Author(s):  
Dusan N. Sormaz ◽  
Pravin Khurana ◽  
Ajit Wadatkar

Process selection as a part of CAPP has captured significant attention in CAPP research. Procedures have been developed for backward and forward algorithms in process selection. Most of these procedures lack the complete integration of process selection into CAPP system. In this paper, we present the results of the development and prototype implementation for process selection module for hole making operations for integration with Math Based Manufacturing System already in use in industrial partner. We have developed architecture and implemented module for rule-based machining process selection of hole making operations. The architecture enables the interface from the Process Selection prototype to Math Based Manufacturing System (APPS). The prototype also includes the user interface for interaction with the process selection procedure. Actions for starting prototype from APPS, performing process selection steps and sending the result back to APPS have been developed and implemented.


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