Force Analysis of the Film in a COF Chip Mounter’s Loader

2004 ◽  
Author(s):  
Dein Shaw ◽  
H. C. Lin
Keyword(s):  
Friction Force ◽  
Relative Motion ◽  
Lower Layer ◽  
Axial Direction ◽  
Tension Force ◽  
Force Distribution ◽  
Force Analysis ◽  
Transportation Vehicle

In this study, the tension force distributions in the film of COF cartridge are studied. It is noted that if the tension force on the film is too high, the interface between chip and film cracked. If the force is too low, there is no enough friction force to keep the COF in fix position when the cartridge is on the transportation vehicle. The relative motion between the chips of lower layer and the film of upper layer will cause the fatigue of interface of chips and film. It is also important to note that due to the friction the tension force at any section of the film is different. To fine the force distribution, a method to determine the tension force is developed and only effect of axial direction is considered. The assumption makes the film behave like a string. The results show that the forces on the film are different whenever the film passes a chip underneath.

Force Analysis of Double Pitch Point Cycloid Drive with Intermediate Rolling Elements and Free Retainer

2015 ◽  
Vol 756 ◽  
pp. 29-34
Author(s):  
E.A. Efremenkov ◽  
E.E. Kobza ◽  
S.K. Efremenkova
Keyword(s):  
Performance Improvement ◽  
Wedge Angle ◽  
Force Distribution ◽  
Force Analysis ◽  
Angle Variation ◽  
Rolling Elements ◽  
Further Development

This paper illustrates the analysis of wedge angle influence on force distribution in the meshing of double pitch point cycloid drive in comparison with single pitch point cycloid drive. Double pitch point cycloid drive may provide smoother performance of transmission at starting period in consequence of wedge angle variation capabilities. Matching initial parameters it is possible to modify the wedge angle and achieve its effective value. The influence of various combinations of initial parameters on the wedge angle and retainer force was studied and presented on diagrams. Some recommendations in designing related to performance improvement are given. The obtained results can be used for further development of better designs of cycloid drives.

Influence of Friction on the Vibratory Response of Structure

2011 ◽  
Vol 189-193 ◽  
pp. 152-159
Author(s):  
Xiao Mei Miao ◽  
Xiao Diao Huang
Keyword(s):  
Friction Force ◽  
Relative Motion ◽  
Vibrational Energy ◽  
Excitation Amplitude ◽  
Vibration Damping ◽  
Lugre Model ◽  
Vibratory Response ◽  
Vibration Properties ◽  
Vibration Responses ◽  
Friction Models

Friction is a phenomenon caused by relative motion, which can be used to absorb vibrational energy. The influence of friction on vibration responses of structures is complex due to the complicacy and nonlinear of the friction itself. In this paper, a 3-DOF spring-damper model with/without friction force was studied to expose how the friction governed the vibratory responses. Several popular friction models were reviewed and LuGre Model was used in this paper. The vibration properties under sine excitation and random were simulated by the Matlab Simulink Software. The results showed that friction absorbed vibration well and vibration damping was rapid. The characteristics of friction influence resulted from comprehensive functions of all factors, such as types of excitation, excitation amplitude and frequency and the location of friction.

Meso-scale mapping of friction force distribution

2002 ◽  
Vol 2002.5 (0) ◽  
pp. 161-162
Author(s):  
Toshimitsu NUMATA ◽  
Akifumi SAKAMOTO ◽  
Atsushi KORENAGA ◽  
Yasuhisa ANDO ◽  
Shinya SASAKI
Keyword(s):  
Friction Force ◽  
Force Distribution ◽  
Meso Scale

Friction Force Distribution Along Time-Varying Contact Line in Helical Gear System

2012 ◽  
Author(s):  
Wen-liang Li ◽  
Li-qin Wang
Keyword(s):  
Friction Force ◽  
Contact Line ◽  
Helical Gear ◽  
Gear System ◽  
Shape Design ◽  
Force Distribution ◽  
Time Varying ◽  
Fundamental Theory ◽  
Impact Reduction ◽  
Instantaneous Position

Based on the theory of energy minimization, a numerical algorithm was developed to calculate friction force distribution along the time-varying contact line in helical gear system. The friction force distribution varies with the instantaneous position of the meshing point and the length of contact line. The friction force was calculated on every meshing point of time-varying contact line via the algorithm. The results show the friction force becomes larger from the tooth root to the pitch point and becomes smaller from the pitch point to the tooth tip. Due to this, there is a significant shock at the pitch point which will generate noise and vibration. The changing law of friction force distribution provides a fundamental theory for modification shape design and impact reduction.

Effect of Combined Motion on Force Transmission of a Flexible Instrument

2014 ◽  
Author(s):  
J. P. Khatait ◽  
D. M. Brouwer ◽  
R. G. K. M. Aarts ◽  
J. L. Herder
Keyword(s):  
Friction Force ◽  
Velocity Ratio ◽  
Axial Direction ◽  
Experimental Results ◽  
Force Transmission ◽  
Rigid Tube ◽  
Combined Motion ◽  
Flexible Instrument ◽  
Translation Motion ◽  
Analytical Result

The force transmission of a flexible instrument through an endoscope is deteriorated due to friction between the contacting surfaces. Friction force along the axial direction can be reduced by combining the translation motion input with rotational motion input at the proximal end of the instrument. The effect of the combined motion on the force transmission is studied for a flexible instrument through a curved rigid tube. A mathematical formula is derived for the reduction in friction force along the axial direction due to the combined motion input. The force transmission of a flexible instrument through a curved rigid tube is analysed using the capstan equation. The ratio of the input and output forces is compared for the combined motion with that of the translation motion only. A ratio ζ is defined to measure the reduction in the friction force along the axial direction due to the combined motion input. The analytical result shows the reduction in the friction force for the combined motion input. A flexible multibody model is set up and various simulations are performed with different motion inputs. The simulation result showed a reduction in the value of ζ in accordance with the analytical result for the given velocity ratio. The results are further validated with the experimental results. The simulation and experimental results show an agreement with the analytical solutions. The knowledge of force transmission with a combination of motions can be used to increase the force fidelity of a flexible instrument in applications like robotic surgery with a flexible instrument.

Experimental and Modeling Studies of Looping Process for Wire Bonding

2013 ◽  
Vol 135 (4) ◽  
Author(s):  
Fuliang Wang ◽  
Yun Chen
Keyword(s):  
Finite Element ◽  
Friction Force ◽  
Material Properties ◽  
High Speed ◽  
Gold Wire ◽  
Tension Force ◽  
Fe Model ◽  
High Speed Camera ◽  
Dynamic Finite Element ◽  
Key Technologies

Looping is one of the key technologies for modern thermosonic wire bonders, and it has been affected by many interacting factors. In this study, the wire looping process was observed with a high-speed camera, and the evolution of wire profiles during looping and the capillary trace were obtained through experiments. A dynamic finite element (FE) model was developed to learn the details of the looping process, where real capillary geometry dimensions, capillary trace, diameter of bonded ball and the gold wire material were used, and the friction force and air tension force were considered. The simulated profiles were compared with those of the experiment. Using the verified FE model, the effects of material properties, capillary parameters, and capillary traces on the looping process were studied, and the relationships between the final profiles and parameters were discussed.

Analysis and Synthesis of Multi-Rotor Aerial Vehicles

2011 ◽  
Author(s):  
Qimi Jiang ◽  
Daniel Mellinger ◽  
Christine Kappeyne ◽  
Vijay Kumar
Keyword(s):  
Experimental Studies ◽  
Force Distribution ◽  
Force Analysis ◽  
Analysis And Synthesis ◽  
Angular Velocities ◽  
Aerial Vehicle ◽  
Position And Orientation ◽  
Configuration Synthesis ◽  
Save Energy ◽  
Optimal Set

This work addresses two basic problems of the multi-rotor aerial vehicle (MRAV). The first problem is the force analysis of the rotors. In order to save energy and maximize the lifetime of a given MRAV, the force distribution of the rotors is analyzed. As a result, an optimal set of angular velocities is obtained. The second problem is the configuration synthesis of the MRAV. In order to maximize the acceleration and improve the maneuverability of the MRAV, the geometric configuration (position and orientation) of the rotors is synthesized. The approaches for analysis and synthesis are presented and demonstrated by several case studies. The obtained results can be applied in the design of the MRAV and used as a guide for experimental studies.

scholarly journals Test on a brake lining damper for structures

1985 ◽  
Vol 18 (3) ◽  
pp. 280-284 ◽  
Author(s):  
R. G. Tyler
Keyword(s):  
Friction Force ◽  
Coefficient Of Friction ◽  
Relative Motion ◽  
Steel Plate ◽  
Hysteresis Loops ◽  
Continuous Movement ◽  
The Coefficient Of Friction ◽  
Brake Lining

Tests were carried out on a brake lining damper intended to dissipate energy between parts of a structure having relative motion during earthquake attack. The device operates by the sliding of a steel plate clamped against a brake lining. Hysteresis loops for the damper showed peaks for the breakaway friction force, when the value of the force was up to twice that obtained for continuous movement. Also values of the coefficient of friction derived from the test were lower than those quoted elsewhere. Further testing is required prior to the use of the method in structures.

Sign in / Sign up

Export Citation Format

Share Document