Fixture Clamping Force Analysis during Milling Process

2013 ◽  
Vol 278-280 ◽  
pp. 385-388 ◽  
Author(s):  
Shao Gang Liu ◽  
Qiu Jin
Keyword(s):  
Analytical Method ◽  
Linear Equations ◽  
Milling Process ◽  
Contact Forces ◽  
Clamping Force ◽  
Contact Deformation ◽  
Force Analysis ◽  
Equilibrium Equations ◽  
Tangential Contact ◽  
Fixture Element

This paper presents a analytical method to calculate the minimum clamping force to prevent slippage between the workpiece and spherical-tipped fixture elements during milling process. After the contact deformation between the workpiece and spherical-tipped fixture element is determined, the relationships between the workpiece displacement and the contact deformations are obtained. Based on the static equilibrium equations, these equations are combined and linear equations are obtained to calculate the tangential contact forces between the workpiece and spherical-tipped fixture element. According to the maximum tangential contact force, the minimum clamping force to prevent slippage between the workpiece and spherical-tipped fixture elements is calculated. At last, this method is illustrated with a simulation example.

A Simple Analytical Method for Teaching Force Analysis of Planar Frictionless Mechanisms

2005 ◽  
Author(s):  
Kazem Abhary
Keyword(s):  
Algebraic Equation ◽  
Analytical Method ◽  
Kinematic Analysis ◽  
Simultaneous Equations ◽  
Degree Of Freedom ◽  
Force Analysis ◽  
Equilibrium Equations ◽  
Planar Mechanisms ◽  
Joint Force ◽  
Teaching Force

A purely analytical method for teaching force analysis of one degree-of-freedom planar frictionless mechanisms has been developed herein. The method uses the vectorial illustration of mechanisms, which is widely used for kinematic analysis of mechanisms too. In this method, a joint-force is determined either via its decomposition into the direction of its adjacent links or from the equilibrium equations of one of these links. Unlike the conventional analytical method which leads to a system of simultaneous equations, this method leads to only one simple algebraic-equation or one simple vectorial-equation at a time. Force analysis of planar mechanisms has always been tedious and time consuming but this method has proved to be simple, straightforward and quick. It is therefore a most suitable tool for teaching mechanisms as it downgrades the project-type problems to the level of classroom tutorials.

Decomposition of stiffness and friction tangential contact forces during periodic motion

2017 ◽  
Vol 94 ◽  
pp. 400-414
Author(s):  
Michael Feldman ◽  
Yaron Zimmerman ◽  
Sagi Sheer ◽  
Izhak Bucher
Keyword(s):  
Periodic Motion ◽  
Contact Forces ◽  
Tangential Contact

Equilibrium Thermodynamics of Combustion by Means of Genetic Algorithms

2005 ◽  
Author(s):  
S. Brusca ◽  
R. Lanzafame ◽  
M. Messina
Keyword(s):  
Equivalence Ratio ◽  
Linear Equations ◽  
Combustion Process ◽  
Genetic Approach ◽  
Equilibrium Equations ◽  
Linear Set ◽  
Wide Range ◽  
Non Linear ◽  
Release Analysis ◽  
Non Linear Equations

In order to carry out an accurate heat release analysis, it is necessary to solve a non linear set of chemical equilibrium equations to calculate concentrations of the species present in cylinder gases during the combustion process. So, the thermodynamics properties of the mixture can be evaluated. The present paper deals with the study of the thermodynamics of combustion using a genetic approach. A genetic algorithm was used to solve the set of non linear equations. The goal of this method is the possibility of solving the equations set in a wide range of pressure, temperature and equivalence ratio combinations, where more traditional methods are often found to fail.

Modeling of tangential contact forces

1998 ◽  
Vol 103 (5) ◽  
pp. 2920-2920 ◽  
Author(s):  
Krister Larsson ◽  
Stephane Barrelet ◽  
Wolfgang Kropp
Keyword(s):  
Contact Forces ◽  
Tangential Contact

An analytical method as a preconditioning modeling for systems of linear equations

2016 ◽  
Vol 37 (2) ◽  
pp. 922-931 ◽  
Author(s):  
H. Saberi Najafi ◽  
S. A. Edalatpanah ◽  
A. H. Refahisheikhani
Keyword(s):  
Analytical Method ◽  
Linear Equations ◽  
Systems Of Linear Equations

Spin moment calculation and its importance in railway dynamics

2009 ◽  
Vol 223 (5) ◽  
pp. 453-460 ◽  
Author(s):  
A Alonso ◽  
J G Giménez ◽  
L M Martín
Keyword(s):  
Contact Problem ◽  
Contact Area ◽  
Vehicle Dynamics ◽  
Contact Forces ◽  
Dissipated Energy ◽  
Shear Stresses ◽  
Spin Moment ◽  
Railway Dynamics ◽  
Tangential Contact ◽  
Original Algorithm

The objective of this work is to analyse the influence of the spin moment generated at the wheel—rail contact area on both vehicle dynamics and dissipated energy that is closely related to wear. From the different methods used in railway simulation programs to model the tangential contact problem, FastSim algorithm has been selected in this work due to its accuracy in the calculation of the contact forces and also because it allows obtaining the spin moment integrating the shear stresses. In the first part of the article the accuracy of FastSim in the calculation of spin moment is analysed. Also, some modifications are introduced in the original algorithm in order to improve its accuracy. In the second part, the influence of the spin moment on the results of some typical situations is presented. It has been checked that its influence on railway dynamics is negligible. On the contrary, it has been found that the value of the dissipated energy can be greatly modified if this parameter is taken into account.

Determination of Muscle Orientations and Moment Arms

1984 ◽  
Vol 106 (3) ◽  
pp. 280-282 ◽  
Author(s):  
K. N. An ◽  
K. Takahashi ◽  
T. P. Harrigan ◽  
E. Y. Chao
Keyword(s):  
Muscle Force ◽  
Experimental Techniques ◽  
Force Analysis ◽  
Equilibrium Equations ◽  
Extensive Experience ◽  
Load Measurement ◽  
Moment Arms ◽  
Advantages And Disadvantages ◽  
Geometric Measurement

In muscle force analysis, orientations and moment arms of the muscles about a joint provide essential coefficients in the equilibrium equations. For the determination of these parameters, several experimental techniques, including geometric measurement, tendon-joint displacement measurement and direct load measurement, are available. Advantages and disadvantages associated with each of the techniques are reviewed and compared based on our extensive experience.

Optimization of Milling Process for Aluminum Alloy Frame Part Based on Milling Force Analysis

2014 ◽  
Vol 575 ◽  
pp. 437-441
Author(s):  
Yi Shu Hao ◽  
Guo Qing Tang ◽  
Meng Zhang
Keyword(s):  
Aluminum Alloy ◽  
Selection Method ◽  
Milling Process ◽  
Parameter Selection ◽  
Force Analysis ◽  
Milling Force ◽  
Finite Element Software ◽  
Milling Parameters ◽  
Machining Errors ◽  
Thin Walled

In order to solve the problem of size guarantee related to thin-walled structure in traditional milling parameter selection, specific aluminum alloy frame part contains curved surface and thin-walled structure is studied. Numerical analysis is used in milling parameter selection method. Machining errors are calculated and checked based on milling force analysis. The milling process is simulated using finite element software. And aluminum alloy frame part processing is optimized from the angle of milling parameters according to the simulation results. Optimized milling parameters scheme is acquired, the results show that both machining precision and efficiency of the frame part are improved.

scholarly journals Simplified Analytical Method for Optimized Initial Shape Analysis of Self-Anchored Suspension Bridges and Its Verification

2015 ◽  
Vol 2015 ◽  
pp. 1-14 ◽  
Author(s):  
Myung-Rag Jung ◽  
Dong-Ju Min ◽  
Moon-Young Kim
Keyword(s):  
Analytical Method ◽  
Bending Moment ◽  
Suspension Bridge ◽  
Suspension Bridges ◽  
Equilibrium Equations ◽  
Initial State ◽  
Initial Shape ◽  
Main Cable ◽  
Initial Shape Analysis ◽  
Bridge Models

A simplified analytical method providing accurate unstrained lengths of all structural elements is proposed to find the optimized initial state of self-anchored suspension bridges under dead loads. For this, equilibrium equations of the main girder and the main cable system are derived and solved by evaluating the self-weights of cable members using unstrained cable lengths and iteratively updating both the horizontal tension component and the vertical profile of the main cable. Furthermore, to demonstrate the validity of the simplified analytical method, the unstrained element length method (ULM) is applied to suspension bridge models based on the unstressed lengths of both cable and frame members calculated from the analytical method. Through numerical examples, it is demonstrated that the proposed analytical method can indeed provide an optimized initial solution by showing that both the simplified method and the nonlinear FE procedure lead to practically identical initial configurations with only localized small bending moment distributions.

On the prediction of passive contact forces of workpiece-fixture systems

2005 ◽  
Vol 219 (3) ◽  
pp. 309-324 ◽  
Author(s):  
Cai-Hua Xiong ◽  
Michael Yu Wang ◽  
Yong Tang ◽  
You-Lun Xiong
Keyword(s):  
Contact Point ◽  
Linear Equations ◽  
Contact Forces ◽  
Contact Model ◽  
Elastic Contact ◽  
Elastic Deformations ◽  
Non Linear ◽  
Determinate System ◽  
Fixture System ◽  
Non Linear Equations

The prediction of passive forces in a frictional workpiece-fixture system is an important problem, since the contact forces have a strong influence on clamp design and on workpiece accuracy during machining. This paper presents a general method for the computation of passive contact forces. Firstly, an indeterminate system of static equilibrium is defined, in which the passive, frictional contact forces cannot be determined arbitrarily as in an actively controlled robotic multifinger grasp. Then, a locally elastic contact model is used to describe the non-linear coupling between the contact forces and elastic deformations at the contact point. This model captures the essence of the passive contact. Further, a set of ‘compatibility’ equations is given so that the relationship can be developed between the elastic deformations at all contacts and the displacement of the workpiece. Finally, combining the force equilibrium, the locally elastic contact model and the ‘compatibility’ conditions, the passive force computation problem is transformed into a determinate system of non-linear equations governing all of the elastic deformations at all of the passive contacts. By solving the resulting non-linear equations, all passive contact forces can be accurately predicted in the frictional workpiece-fixture system. This method is illustrated with example cases. The method presented here may also have an application to other passive, indeterminate problems such as power grasps in robotics.

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