Navigation of Microrobots by MRI: Impact of Gravitational, Friction and Thrust Forces on Steering Success

2021 ◽  
Author(s):  
Cyril Tous ◽  
Ning Li ◽  
Ivan P. Dimov ◽  
Samuel Kadoury ◽  
An Tang ◽  
...  
Keyword(s):  
Thrust Forces

scholarly journals Influence of tool cooling on thrust forces in tapping operations of reinforced polyamide

2017 ◽  
Vol 13 ◽  
pp. 343-347 ◽  
Author(s):  
R. Domingo ◽  
R. Calvo ◽  
M.M. Marín ◽  
B. de Agustina
Keyword(s):  
Tool Cooling ◽  
Thrust Forces

Development of Analytical Force Model for End Milling of Magnesium Matrix Composites

2020 ◽  
Author(s):  
Nishita Anandan ◽  
M. Ramulu
Keyword(s):  
End Milling ◽  
Coefficient Of Thermal Expansion ◽  
Cutting Edge ◽  
Force Model ◽  
Matrix Composites ◽  
Magnesium Metal ◽  
Magnesium Matrix Composites ◽  
The Matrix ◽  
Thrust Forces ◽  
Good Agreement

Abstract An analytical approach to predict the cutting forces in end milling of magnesium metal matrix composite is presented in this study. The model was developed by identifying three events that occur when the cutting edge encounters the composite, when an element of the cutting edge encounters just the particles, it may fracture the particle, when the element encounters pure ductile matrix, plastic deformation occurs and when the element is in contact with both the particle and matrix, particle debonding occurs due to mismatch in coefficient of thermal expansion. The probability of these events was estimated using the particle concentration and the distribution in the matrix. A cutting force model is developed by considering the stresses and forces experienced by the cutting edge contributed by these events. The predicted feed forces and the measured forces are in good agreement for most of the cutting conditions. While, the predictive thrust forces were found to diverge at higher feed of 1 mm/rev.

Investigation of Drilling Temperature in Relation to Machining Conditions and Cutting Time

2020 ◽  
Author(s):  
Charbel Y. Seif ◽  
Ilige S. Hage ◽  
Ahmad M. R. Baydoun ◽  
Ramsey F. Hamade
Keyword(s):  
Temperature Rise ◽  
Cutting Speed ◽  
Drilling Depth ◽  
Machining Center ◽  
Drilling Temperature ◽  
Wide Range ◽  
Set Up ◽  
Type 3 ◽  
Flank Surface ◽  
Thrust Forces

Abstract Controlling drilling temperature and thrust forces play a significant role in reducing tool wear and improving machining efficiency. In this work, drilling experiments are set up to measure flank surface temperature via thermocouple sensor wires passed through the coolant holes of 10mm twist drill and brazed to the drill flank surface. The testing setup is an inverted drilling jig where the workpiece (Aluminum 6061-T6 rod) is chucked into the spindle of a vertical machining center. Thrust forces are co-measured using Kistler type 3-component plate dynamometer attached to the table. A design of experiment (DOE) using JMP-SAS/STAT® was adopted for selecting combinations of cutting speed and feed values that cover a wide range. Drilling temperature rise and thrust forces are found to correlate with cutting conditions of feed (f), maximum cutting speed (V), and drilling depth (Dp). Nonlinear regression analysis produced correlating equations of flank temperature rise and thrust forces to conditions and follow a mechanistic power law of the form a1fa2Va3Dpa4 where a1, a2, a3 and a4 are identified via regression fitting.

Measuring leg thrust forces in the common starling

1996 ◽  
Vol 199 (2) ◽  
pp. 435-439 ◽  
Author(s):  
R Bonser ◽  
J Rayner
Keyword(s):  
Body Mass ◽  
Mass Dependence ◽  
Reaction Forces ◽  
The Common ◽  
Thrust Forces ◽  
Significant Mass

We describe the design of a force-transducing perch which measures the reaction forces of small birds taking off and landing. In common starlings, landing forces are lower than take-off forces, because the bird may decelerate prior to landing by using its wings. Both landing and take-off forces are significantly correlated with body mass; however, the angles of these reaction forces show no significant mass-dependence and are not repeatable within individuals. Diversity in take-off or landing strategy could be advantageous in confusing predators.

Initial Investigation Into Helical Milling of Laminated Stacks of Electrical Steel

2012 ◽  
Author(s):  
Howard Liles ◽  
J. Rhett Mayor
Keyword(s):  
Electrical Steel ◽  
Thrust Force ◽  
Initial Study ◽  
Helical Milling ◽  
Burr Formation ◽  
Spring Back ◽  
Plunge Milling ◽  
Axial Thrust ◽  
Electrical Steels ◽  
Thrust Forces

This paper serves to report the findings of an initial study on the holing of laminated stacks of electrical steels. Three different holing methods were considered: plunge milling, helical milling (orbit milling), and drilling. Stack delamination, axial thrust force, and burr formation were measured at various feed rates for each process and utilized as comparison metrics. Results from the initial experimental investigation indicate that drilling produces significant burr and plunge milling, whilst reducing burr formation compared to drilling, led to delamination of the stack. Helical milling minimized thrust forces, avoided delamination and minimized burr formation. An interesting spring back effect was also observed during the cutting of the laminated stacks. It is concluded that helical milling is a viable and effective processing method for making holes in laminated stack of hard electrical steels.

Cutting Process of Double Angle Drill

2015 ◽  
Vol 651-653 ◽  
pp. 1211-1216
Author(s):  
Shouichi Tamura ◽  
Takashi Matsumura
Keyword(s):  
Flow Direction ◽  
Wedge Angle ◽  
Burr Formation ◽  
Force Model ◽  
Workpiece Material ◽  
Fiber Reinforced Plastic ◽  
Chip Flow ◽  
Reinforced Plastic ◽  
Cutting Processes ◽  
Thrust Forces

Double angle drills have recently been used to improve the surface finish in drilling. The double angle drill consists of lower edges at a large wedge angle and upper edges at a small wedge angle on the lips. The paper discusses the cutting processes of the double angle drill in analysis and experiment. A force model is applied to simulate the cutting force and the chip flow direction. The cutting tests are conducted to verify the force model in drilling of carbon fiber reinforced plastic (CFRP) and aluminum alloy (A7075) with a single and a double angle drills. The double angle drill is effective in control of delamination in drilling of CFRP due to reduction of the thrust force. Meanwhile, in drilling of A7075, the small wedge angle of the upper edges on the double angle drill is not effective in reduction of the thrust forces. The curved edge at the end of the lip, in turn, promotes burr formation in drilling of A7075. The effectiveness of the double angle drill depends on the workpiece material.

The thrust measurement system research for combined nozzle in small space

2018 ◽  
Vol 41 (4) ◽  
pp. 1149-1159
Author(s):  
Yonghua Lu ◽  
Jing Li ◽  
Xiang Zhang ◽  
Yang Li
Keyword(s):  
Measurement System ◽  
Force Sensor ◽  
Test Method ◽  
Small Space ◽  
System A ◽  
Calibration Experiment ◽  
Different Types ◽  
Thrust Measurement ◽  
Nozzle Thrust ◽  
Thrust Forces

For measuring the thrust of combined nozzles in satellite thruster with a small space, the test method that the nozzle directly sprays on the load baffle is employed in this paper. The key problem is how to design the positions of 10 load baffles and how to construct the measurement system. A set of complete and automatic nozzle thrust measurement system is designed and built, and the influence of the load baffle applied on the flow field of nozzles is analyzed using the software FLUENT. Furthermore, the load surface locations of the sensors for the different types of nozzles are analyzed. We draw the conclusion that the load baffle position should range from 4–8 mm for the I-type nozzle and range in 6–12 mm for II-type and III-type nozzle. The correction coefficients of the thrust forces for all channels of the measurement system are determined in the calibration experiment. The uncertainty of measurement system is estimated and the error source of the measurement system is traced. We found that the systematic uncertainty is mainly contributed by the A-type uncertainty which is related with the nozzle dimension and its inner structure. The B-type uncertainty of system is contributed by the force sensor.

scholarly journals Comparative study for designing the horizontal thrust blocks in pipelines for water and sewage networks

2021 ◽  
Author(s):  
Osama S. Hussien
Keyword(s):  
Drinking Water ◽  
Comparative Study ◽  
Thrust Force ◽  
Block Design ◽  
Surrounding Area ◽  
Design And Implementation ◽  
Horizontal Thrust ◽  
Bend Angles ◽  
Thrust Forces ◽  
Block Dimensions

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.

Coupled Eulerian-Lagrangian Simulation of Indexable Drilling

2021 ◽  
Author(s):  
Daniel Svensson ◽  
Tobias Andersson ◽  
Andreas Andersson Lassila
Keyword(s):  
Thrust Force ◽  
Rotational Velocity ◽  
Measured Data ◽  
Lagrangian Simulation ◽  
Lagrangian Framework ◽  
Temperature Distributions ◽  
Total Thrust ◽  
Hole Axis ◽  
Thrust Forces ◽  
Friction Modelling

Abstract This paper presents finite element simulations of indexable drilling of AISI4140 workpieces. The Coupled-Eulerian-Lagrangian framework is employed and the focus is to predict the drilling torque around the hole axis, thrust force, temperature distributions and chip geometries. The cutting process is modelled separately for peripheral and central insert. Then, the total thrust force and torque are predicted by superposing the predicted result for each insert. Experiments and simulations are conducted at a constant rotational velocity of 2400 rpm and feed rates of 0.13, 0.16 and 0.18 mm/rev. While the predicted torques are in excellent agreement, the thrust forces showed discrepancies of 12 - 20% to the experimental measured data. Effects of the friction modelling on the predicted torque and thrust force are outlined and possible reasons for the thrust force discrepancies are discussed in the paper. Additionally, the simulations indicate that the tool and workpiece temperature distributions are virtually unaffected by the feed rate.

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