Critical thrust force and critical feed rate in drilling flax fibre composites: A comparative study of various thrust force models

2019 ◽  
Vol 165 ◽  
pp. 222-232 ◽  
Author(s):  
Aiman Akmal Abdul Nasir ◽  
Azwan Iskandar Azmi ◽  
Tan Chye Lih ◽  
Mohd Shukry Abdul Majid
2014 ◽  
Vol 10 (4) ◽  
pp. 611-630 ◽  
Author(s):  
Amrinder Pal Singh ◽  
Manu Sharma ◽  
Inderdeep Singh

Purpose – Damage due to delamination is an important issue during drilling in polymer-matrix composites (PMCs). It depends on thrust force and torque which are functions of feed rate. Transfer function of thrust force with feed rate and torque with feed rate is constructed through experiments. These transfer functions are then combined in state-space to formulate a sixth-order model. Then thrust force and torque are controlled by using optimal controller. The paper aims to discuss these issues. Design/methodology/approach – A glass fiber reinforced plastic composite is drilled at constant feed rate during experimentation. The corresponding time response of thrust force and torque is recorded. Third-order transfer functions of thrust force with feed rate and torque with feed rate are identified using system identification toolbox of Matlab®. These transfer functions are then converted into sixth-order combined state-space model. Optimal controller is then designed to track given reference trajectories of thrust force/torque during drilling in composite laminate. Findings – Optimal control is used to simultaneously control thrust force as well as torque during drilling. There is a critical thrust force during drilling below which no delamination occurs. Therefore, critical thrust force profile is used as reference for delamination free drilling. Present controller precisely tracks the critical thrust force profile. Using critical thrust force as reference, high-speed drilling can be done. The controller is capable of precisely tracking arbitrary thrust force and torque profile simultaneously. Findings suggest that the control mechanism is efficient and can be effective in minimizing drilling induced damage in composite laminates. Originality/value – Simultaneous optimal control of thrust force and torque during drilling in composites is not available in literature. Feed rate corresponding to critical thrust force trajectory which can prevent delamination at fast speed also not available has been presented.


Materials ◽  
2021 ◽  
Vol 14 (16) ◽  
pp. 4468
Author(s):  
Vigneshwaran Shanmugam ◽  
Uthayakumar Marimuthu ◽  
Sundarakannan Rajendran ◽  
Arumugaprabu Veerasimman ◽  
Adamkhan Mahaboob Basha ◽  
...  

Filled hybrid composites are widely used in various structural applications where machining is critical. Hence, it is essential to understand the performance of the fibre composites’ machining behaviour. As such, a new hybrid structural composite was fabricated with redmud as filler and sisal fibre as reinforcement in polyester matrix. The composite was then tested for its drilling performance. A comprehensive drilling experiment was conducted using Taguchi L27 orthogonal array. The effect of the drill tool point angle, the cutting speed, the feed rate on thrust force, delamination, and burr formation were analysed for producing quality holes. The significance of each parameter was analysed, and the experimental outcomes revealed some important findings in the context of the drilling behaviour of sisal fibre/polyester composites with redmud as a filler. Spindle speed contributed 39% in affecting the thrust force, while the feed rate had the maximum influence of ca. 38% in affecting delamination.


2021 ◽  
Vol 5 (7) ◽  
pp. 189
Author(s):  
Muhammad Hafiz Hassan ◽  
Jamaluddin Abdullah ◽  
Gérald Franz ◽  
Chim Yi Shen ◽  
Reza Mahmoodian

Drilling two different materials in a layer, or stack-up, is being practiced widely in the aerospace industry to minimize critical dimension mismatch and error in the subsequent assembly process, but the compatibility of the drill to compensate the widely differing properties of composite is still a major challenge to the industry. In this paper, the effect of customized twist drill geometry and drilling parameters are being investigated based on the thrust force signature generated during the drilling of CFRP/Al7075-T6. Based on ANOVA, it is found that the maximum thrust force for both CFRP and Al7075-T6 are highly dependent on the feed rate. Through the analysis of maximum thrust force, supported by hole diameter error, hole surface roughness, and chip formation, it is found that the optimum tool parameters selection includes a helix angle of 30°, primary clearance angle of 6°, point angle of 130°, chisel edge angle of 30°, speed of 2600 rev/min and feed rate of 0.05 mm/rev. The optimum parameters obtained in this study are benchmarked against existing industry practice of the capability to produce higher hole quality and efficiency, which is set at 2600 rev/min for speed and 0.1 mm/rev for feed rate.


Metals ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 854
Author(s):  
Muhammad Aamir ◽  
Khaled Giasin ◽  
Majid Tolouei-Rad ◽  
Israr Ud Din ◽  
Muhammad Imran Hanif ◽  
...  

Drilling is an important machining process in various manufacturing industries. High-quality holes are possible with the proper selection of tools and cutting parameters. This study investigates the effect of spindle speed, feed rate, and drill diameter on the generated thrust force, the formation of chips, post-machining tool condition, and hole quality. The hole surface defects and the top and bottom edge conditions were also investigated using scan electron microscopy. The drilling tests were carried out on AA2024-T3 alloy under a dry drilling environment using 6 and 10 mm uncoated carbide tools. Analysis of Variance was employed to further evaluate the influence of the input parameters on the analysed outputs. The results show that the thrust force was highly influenced by feed rate and drill size. The high spindle speed resulted in higher surface roughness, while the increase in the feed rate produced more burrs around the edges of the holes. Additionally, the burrs formed at the exit side of holes were larger than those formed at the entry side. The high drill size resulted in greater chip thickness and an increased built-up edge on the cutting tools.


2017 ◽  
Vol 748 ◽  
pp. 254-258
Author(s):  
Chang Yi Liu ◽  
Bai Shou Zhang ◽  
Suman Shrestha

Drilling experiments of titanium alloy Ti6Al4V were conducted. Taking the speed and feed as the process variables, a set of experimental cutting forces are obtained and compared. From the experimental results it is concluded that within the experimental extent the thrust force and torque of drilling process rises with the feed rate. The lower spindle speed resulted in the greater amount of thrust. Feed rates have greater influence on the thrust force than the spindle speed. The combination of greater feed rate and lower spindle speed results in the maximum amount of thrust. However, combination of greater feed rate and spindle speed resulted in maximum amount of torque.


Author(s):  
Osama S. Hussien

Abstract The thrust block is one of the most widely recognized methods of resisting thrust forces. This type of infrastructure should be installed in bends, dead ends, tees and wyes. Thrust blocks perform the function of transferring thrust force to the ground safely. Thrust block dimensions are designed based on hydrostatic pressures, bend angles, and soil properties in the surrounding area. Several codes exist for designing thrust blocks, but we focus on Egyptian code for design and implementation of pipelines for drinking water and sewage networks (ECDIPWSN) and the American Water Works Association (AWWA). In this methodology, the steps of thrust block design by the codes are demonstrated and applied individually to one of the published papers. The goal of the study is to find the optimum percentages between the dimensions of the block in the two codes and to compare the quantity of concrete after the block is designed by each code. Based on the research, it was found that the concrete amount of the block designed by (AWWA) is smaller than that designed by (ECDIPWSN). HIGHLIGHT Results of the study discovered the volume of the thrust block created by the AWWA method was smaller than the volume created by the ECDIPWSN method when excavation depth was low but was larger when excavation depth was large.


2014 ◽  
Vol 564 ◽  
pp. 501-506 ◽  
Author(s):  
Mohd Azuwan Maoinser ◽  
Faiz Ahmad ◽  
Safian Shariff ◽  
Tze Keong Woo

Drill point angle of twist drill has a significant effect on thrust force and delamination factor on drilled holes in fiber reinforced polymer (FRP) composites. In this study, three drill point angle of twist drill; 85°, 118° and 135° were used to drill holes in hybrid fiber reinforced polymeric composite (HFRP). HFRP composites were fabricated using vacuum infusion molding (VIM) technique. The test samples were cured at 90°C for two hours. In drilling process various drill point angle and feed rate were employed to investigate the effect of both parameters on thrust force and delamination factor when drilling the HFRP composite. The results showed that small drill point angle and low feed rate can reduce the thrust force leading to the reduction of damage factor at the holes entrance and exit.


2015 ◽  
Vol 825-826 ◽  
pp. 1063-1067
Author(s):  
Marta Fortea-Verdejo ◽  
Elias Bumbaris ◽  
Koon Yang Lee ◽  
Alexander Bismarck

Loose hierarchical flax fibres/polypropylene composites were manufactured in a simple way based on a paper-making process in order to include nanocellulose and allow the hornification of the nanofibres in a controlled manner. The effect of flax fibre content on the flax/polypropylene composites and the influence of nanocellulose on the properties of these composites are discussed. By increasing the flax content a slight decrease of the tensile strength and an increase of the Young´s modulus were observed. On the other hand, no significant effect was noticed when increasing the bacterial cellulose content in the composites.


2014 ◽  
Vol 102 ◽  
pp. 94-99 ◽  
Author(s):  
F. Duc ◽  
P.E. Bourban ◽  
J.-A.E. Månson
Keyword(s):  

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