A Possible New Greco-Carian Contact Phenomenon

Keyword(s):  
2014 ◽  
Vol 660 ◽  
pp. 8-12
Author(s):  
J.B. Saedon ◽  
Noor Aniza Norrdin ◽  
Mohd Azman Yahaya ◽  
N.H. Mohamad Nor ◽  
Mohd Zulhafiz Md Salih

Chip formation is a dynamic process that is often nonlinear in nature. A chip may not form when the depth of cut is less than a minimum chip thickness. It is aimed to investigate influence of depth of cut on contact phenomenon in micromachining. This paper presents a series of simulation works by finite element method on depth of cut effect on micromachining. A model is developed with consideration of the Johnson-Cook material and Arbitrary Lagrangian–Eulerian (ALE) method. In this work investigate the effect of depth of cut on the contact phenomenon during micromachining AISI D2. The results of the analysis are showed in aspects of interrelationship between material separation and frictional shear contact, distribution of stick-slide regions and contact stress on the work piece and cutting tool. It is found that the sticking and sliding was occurred on three zones as primary, secondary and tertiary shear zone. The contact phenomena can be showed around the tool edge radius where material flows around it and piles in front of the cutting tool through material separation. The investigation of contact phenomena inclusive under three criteria such as a/r < 1, a/r > 1 and a/r = 1 on positive rake angle.


2015 ◽  
Vol 137 (6) ◽  
Author(s):  
Tsuyoshi Inoue ◽  
Yuki Takezaki ◽  
Kentaro Takagi ◽  
Kohei Okumura

The gyroscopic exercise tool which utilizes a gyroscopic effect caused by the whirling motion of a high-speed rotating body to train the antebrachial muscle is considered. When an input motion of 3–5 Hz is added to the case, the rotor spins at thousands of rpm whirling with a precession motion which is synchronous to the input motion given to the case. This tool utilizes a contact phenomenon between the rotor and the case to generate this high-speed spin motion. This paper develops its dynamical model considering the transition among noncontacting, rolling, and sliding conditions. The dynamical characteristics of its motions are numerically investigated and are also confirmed in the experiment.


2013 ◽  
Vol 198 ◽  
pp. 67-72
Author(s):  
Marek Stania

This paper presents the modeling problem connected with the autonomous transport vehicle designed at Hochschule Ravensburg-Weingarten. The forward and inverse kinematics problem of eight-wheeled autonomous transport vehicle have been formulated and solved, additionally examples of simulation results representing the changes of individual motion parameters have been presented. Contact phenomenon between foundation and drive wheel has been taken into account in the kinematics model. Motion trajectory and velocity of the selected point belonging to the platform have been intended while the inverse kinematics problem has been solved. The forward kinematics problem has been worked out in order to verify correctness of the studied kinematics model. The presented simulation results point out compatibility of the worked out kinematics model of investigated object. The worked out models allow carrying out analysis of object motion through simulation investigations on the basis of proposed computational model.


Author(s):  
Masih Mahmoodi ◽  
Mehrdad Farid ◽  
Mohammad Eghtesad

In this paper, dynamic equations of a robot manipulator subject to compliant contact/impact with the environment are derived using nonlinear elastodynamic approach. Then, a sliding mode impedance algorithm is proposed to control compliant impact/contact dynamics of the robot manipulator with an arbitrary environment. Impact/contact phenomenon can be regarded as a perturbation due to an abrupt change of system’s velocity. Thus the need to have robust characteristics in such systems especially after impact seems to be evident. The performance of the proposed controller is compared against standard second order impedance controller through numerical simulation studies. Finally, simulation results are provided to show the effectiveness of the proposed algorithm.


1997 ◽  
Vol 119 (2) ◽  
pp. 169-177 ◽  
Author(s):  
W. H. Wang ◽  
C. H. Tseng ◽  
C. B. Tsay

This paper proposes and analyzes a new meshing condition between a modified hyperboloidal roller follower and a spatial cam surface. This new geometrical model can be utilized to avoid the edge contact phenomenon between a cylindrical roller follower and its mating cam surface. In the new model a modified hyperboloidal roller follower is selected to replace the original cylindrical roller follower. Once the new spatial cam mechanism is modeled by means of surface contact analysis (SCA), the contact condition between the modified hyperboloidal roller follower and the cam surface is clearly derived. Errors in the displacement function and the contact path arising from assembly errors are also analyzed. This study assists the manufacture and assembly of more accurate and higher quality spatial cam mechanisms.


2019 ◽  
Vol 70 (3) ◽  
pp. 153-161
Author(s):  
Hoa Pham Trong

Effect of oil temperature and viscosity on the ring gear orbit in the internal gear motor and pump is analyzed in this study. The mobility method is used to calculate the ring gear orbit. The mathematical model of oil viscosity and temperature is then integrated into the mobility method. The simulation results point out that the oil temperature and viscosity have great effect on the eccentricity, position angle and minimum oil film thickness. The metal - to - metal contact phenomenon occurs if internal gear motor and pump operates under high values of oil temperature or low values of oil viscosity conditions.


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