Circular Saw Vibration Control by Induction of Thermal Membrane Stresses

1981 ◽  
Vol 103 (1) ◽  
pp. 81-89 ◽  
Author(s):  
C. D. Mote ◽  
G. S. Schajer ◽  
S. Holo̸yen
Keyword(s):  
Vibration Control ◽  
Induction Heating ◽  
Transverse Vibration ◽  
Critical Speed ◽  
Dimensional Accuracy ◽  
Optimal Temperature ◽  
Blade Vibration ◽  
Circular Saw ◽  
Speed Stability ◽  
Circular Saws

Circular saw transverse vibration and product dimensional accuracy were measured during a series of production experiments in which sawblade vibration was controlled by the deliberate introduction of thermal membrane stresses. Induction heating near the saw collar was used to control the temperature difference between two concentric annular zones on the sawblade surface. Optimal temperature conditions were predicted using the critical speed stability theory for symmetrical circular saws and these predictions were verified through production experiments. Feedback control of sawblade temperature was successfully demonstrated in production as a means of reducing blade vibration and improving dimensional accuracy.

A Feedback Vibration Controller for Circular Saws

1979 ◽  
Vol 101 (1) ◽  
pp. 44-49 ◽  
Author(s):  
R. W. Ellis ◽  
C. D. Mote
Keyword(s):  
Transverse Vibration ◽  
Laboratory Tests ◽  
Cutting Performance ◽  
Laboratory Findings ◽  
Circular Saw ◽  
Theoretical Predictions ◽  
Control Production ◽  
Proportional Derivative Controller ◽  
Circular Saws ◽  
Stiffness And Damping

Transverse vibration of circular saws is detrimental to their cutting performance. A feedback controller which increases the transverse stiffness and damping of a circular saw is analyzed, designed and tested. The proportional-derivative controller suppresses saw vibration with electromagnetically induced forces. Laboratory tests confirm theoretical predictions and demonstrate stiffness and damping increases greater than 400 percent with control. Production tests on the controller support the laboratory findings.

Confirmation of the Critical Speed Stability Theory for Symmetrical Circular Saws

1975 ◽  
Vol 97 (3) ◽  
pp. 1112-1118 ◽  
Author(s):  
C. D. Mote ◽  
S. Holoyen
Keyword(s):  
Critical Speed ◽  
Radiation Thermometer ◽  
Optimal Operation ◽  
Direct Application ◽  
Experimental Program ◽  
Speed Prediction ◽  
Speed Stability ◽  
Product Thickness ◽  
Conditions Of Stability ◽  
Circular Saws

The critical speed theory for circular saws predicts conditions of stability when a saw remains plane and cuts a straight path, and conditions of instability when the saw is no longer plane and no longer produces accurate cuts. This paper presents results of an experimental program on a production process which shows near perfect correspondence between the theoretical critical speed prediction and the measured product accuracy. The critical speed computation required measurement of the production blade temperature with a radiation thermometer and the product accuracy was independently evaluated as the standard deviation of the product thickness. The critical speed theory has direct application to both optimal design and optimal operation of circular saws.

Feedback Control of Saw Blade Temperature With Induction Heating

1978 ◽  
Vol 100 (2) ◽  
pp. 119-126 ◽  
Author(s):  
C. D. Mote ◽  
S. Holo̸yen
Keyword(s):  
Induction Heating ◽  
Effective Means ◽  
Coil Design ◽  
Transient Heating ◽  
Circular Saw ◽  
Steady State Temperature ◽  
Saw Blade ◽  
Circular Saws ◽  
Axisymmetric Temperature ◽  
Basic Induction

Control of the axisymmetric temperature distribution in a circular saw has been shown to be an effective means of reducing blade vibrations. Theoretical and supporting experimental analyses of a basic induction heating coil design are presented here. An IR thermometer was designed to measure the blade temperature. Transient heating, transient cooling and steady state temperature experiments on circular saws were conducted both in the laboratory and in production. The true set point temperature was maintained to within 2 C.

scholarly journals Experimental and Numerical Crack Initiation Analysis of the Compressor Blades Working in Resonance Conditions

2011 ◽  
Vol 2011 (3) ◽  
pp. 134-153
Author(s):  
Lucjan Witek
Keyword(s):  
Finite Element ◽  
Crack Initiation ◽  
Transverse Vibration ◽  
Numerical Models ◽  
Fatigue Behavior ◽  
Time History ◽  
Fatigue Properties ◽  
Compressor Blades ◽  
Blade Vibration ◽  
Number Of Cycles

Experimental and Numerical Crack Initiation Analysis of the Compressor Blades Working in Resonance ConditionsThis paper presents the results of a complex experimental and numerical crack initiation analysis of the helicopter turbo-engine compressor blades subjected to vibrations. A nonlinear finite element method was utilized to determine the stress state of the blade during the first mode of transverse vibration. In this analysis, the numerical models without defects as well as those with V-notches were defined. The quality of the numerical solution was checked by the convergence analysis. The obtained results were next used as an input data into crack initiation (ε-N) analyses performed for the load time history equivalent to one cycle of the transverse vibration. In the fatigue analysis, the different methods such as: Neuber elastic-plastic strain correction, linear damage summation and Palmgreen-Miner rule were utilized. As a result of ε-N analysis, the number of load cycles to the first fatigue crack appearing in the compressor blades was obtained. Moreover, the influence of the blade vibration amplitude on the number of cycles to the crack initiation was analyzed. Values of the fatigue properties of the blade material were calculated using the Baumel-Seeger and Muralidharan methods. The influence of both the notch radius and values of the UTS of the blade material on the fatigue behavior of the structure was also considered. In the last part of the work, the finite element results were compared with the results of experimental vibration HCF tests performed for the compressor blades.

The Mechanical Analysis of the Composite Reinforced Circular Saw Blade

2011 ◽  
Vol 228-229 ◽  
pp. 484-489
Author(s):  
Xiao Ling Wang ◽  
Zhong Jun Yin ◽  
Chao Zhang
Keyword(s):  
Volume Fraction ◽  
Mechanical Analysis ◽  
Loading Conditions ◽  
Circular Saw ◽  
Model And Simulation ◽  
Circular Saw Blade ◽  
Saw Blade ◽  
Reinforcement Model ◽  
Circular Saws ◽  
Composite Reinforcement

Thinner saw blades cannot resist large lateral cutting forces due to their lower stiffness. In this paper we propose a composite reinforcement method to improve the mechanical properties of circular saw blades. We analyze and simulate the stress and strain fields of our proposed reinforced circular saws by Finite element method. Our analytical results contain not only influences of reinforcing parameters but also loading conditions on the lateral stiffness and the natural frequency of composite saw blades. Here the reinforcing parameters include: 1) the reinforcement location on circular saw blades, 2) the volume fraction of the reinforcements, 3) the number of the reinforcements; and loading conditions include: 1) the cutting force, 2) the rotational speed. Our composite reinforcement model and simulation results can contribute to a better design of circular saw blades.

scholarly journals Analysis a cutting edge geometry influence on circular saw teeth at the process of crosscutting wood

2009 ◽  
Vol 57 (5) ◽  
pp. 177-182 ◽  
Author(s):  
Ján Kováč ◽  
Milan Mikleš
Keyword(s):  
Cutting Tools ◽  
Measurement Procedure ◽  
Cutting Edge ◽  
Production Costs ◽  
Cutting Process ◽  
Detailed Measurement ◽  
Edge Geometry ◽  
Circular Saw ◽  
Measuring Devices ◽  
Circular Saws

Nowadays, the wood cutting process looks like a technological scheme consisting of several connected and relatively inseparable parts. The crosscutting wood is the most widespread in the process of fo­rest exploitation; it is used at tree exploitation, shortening stems and assortment production. The article deals with the influence of the cutting edge geometry of circular saws on the torque and also on the cutting performance at the crosscutting wood therefore there is the influence on the whole cutting process. In the article there is described detailed measurement procedure, used measuring devices and the process of results analysis. Knowledge of wood crosscutting process and choice of suitable cutting conditions and cutting tools will contribute to decrease production costs and energy saving.

Experiments on the Active Control of Circular Disk Vibration

2001 ◽  
Author(s):  
J. B. Qiu ◽  
X. Q. Huang ◽  
D. Q. Wang
Keyword(s):  
Control System ◽  
Active Control ◽  
Transverse Vibration ◽  
Circular Disk ◽  
Experimental Results ◽  
Electromagnetic Actuator ◽  
Computer Memory ◽  
Circular Saw ◽  
Mechanical Element

Abstract Circular disk is a basic mechanical element, which is used widely in industry such as turbine machine, circular saw, and computer memory. Considering the requirements for the actuator to control the transverse vibration of circular disk, the non-contact electromagnetic actuator which can produce large actuating force is used, and a whole set of control system that is composed of analog components is built. The good experimental results are obtained by using the control system to control the transverse vibration of circular disk.

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