The inertia is driven by a velocity source via a stick slip friction element. May 25, 2016 the model is developed by mejbahul sarker. An inertia is connected to a fixed point by spring and damper. Aug 10, 20 as the system change from stick to slip the mass velocity increased until it reached maximum value 1. A mechanical rotational system with stick slip friction. Below is a simple, heuristic description of stickslip phenomena using classical mechanics that is relevant for engineering descriptions. Modeling and simulation of the self excited stick slip system using bondsim tools 55 this investigation tends to find out if it is possible to limit the maximal amplitude with external excitation. This model shows a mechanical rotational system with stickslip friction. Initially, the surface root mean square rms of the roughness is close to. In reality this motion is jerky or intermittent because the objects slow during shear periods and accelerate following the shear.
This model shows a mechanical rotational system with stick slip friction. I was thinking to model the stickslip condition by using events but i do not know to define the triggering quantity to move from sticking to slipping. How to measure, prevent, and eliminate stickslip and noise. In this paper an important problem related to stickslip chaos prediction is successfully solved. The theoretical study of the stickslip friction phenomenon, which appears in some lowspeed contacts, and its simulation using simulink is presented. In this article an attempted was investigated to solve the stick slip oscillation by matlab software with one mathematical equation only instead of using three separated equation resulte dfrom. The sum of the coulomb and stribeck frictions at the vicinity of zero velocity is often referred to as the. Using signum function in matlab software simplifies the method required to solve the stick slip equation. The stribeck friction, t s, is the negatively sloped characteristics taking place at low velocities see. If i am correct, the motion should start when mu s n where s is the static. Stick slip definition is movement of two surfaces relative to each other that proceeds by a series of jerks caused by alternate sticking from friction and sliding when the friction is overcome by an applied force. The slipstick phenomenon, as described in the above chapter, is a friction induced vibration and occurs mainly due to the nonlinear and velocity dependent friction parameter.
In addition to detecting stick slip, sensors placed directly below the top drive can be used to perform highlyaccurate tests of wellbore friction factor. Investigation of slip stick process is carried out on a model that includes only the brake disc and the brake pad. But what i would like to model is the whole system behaviour, thus including also the stickslip behaviour. Simulink model for teaching the stick slip friction phenomenon in machine vibration and noise course e. This process is continuously repeated while the objects are sliding. Investigate stick slip intervals with one equation. It possesses a challenging impact on analysis of all mechanical systems with friction, since many of them can be modelled by two degreesoffreedom objects awrejcewicz and lamarque, 2003.
The viscous friction, t v, opposes motion with the torque directly proportional to the relative velocity. Under vacuum, an additional power of 3 mw must be supplied to overcome the observed stickslip friction. To the unaided eye the motion of sliding objects appears steady. Solving ode with coulomb friction mathworks, inc matlab. The friction element has a difference between the breakaway and the coulomb frictions, resulting in stick slip motion of the inertia. Heslot, f baumberger, t perrin, b caroli, b caroli, c. Stickslip detection and frictionfactor testing with. Investigate stick slip intervals with one equation of. The inertia is driven by a velocity source via a stickslip friction element. Simulink model for teaching the stick slip friction. As the system change from stick to slip the mass velocity increased until it reached maximum value 1. Using surface torque to detect stickslip is desirable because it alleviates the need to use a downhole drilling dynamics tool which can be prohibitively expensive. A single unitary mass with friction was pulled by a spring to simulate stick slip motion. Investigate stick slip intervals with one equation of motion.
Stickslip vibrations induced by alternate friction models. When amplitude of excitation frequency equals zero u00 n, the stationary system is out of equilibrium because of friction force action. The drop in the friction force at low velocities is the stribeck e. A continuous stick slip friction model is used to determine the coefficient of friction based on the relative rotational speed of the two parts connected by the lead screw. Pdf investigate stickslip intervals with one equation. The constraint force in the lead screw is measured and used to calculate the friction torque within the lead screw. Correlation between nanosecond xray flashes and stick. In the stick stage, it is treated as in static equilibrium. Stickslip definition of stickslip by merriamwebster. Stickslip definition is movement of two surfaces relative to each other that proceeds by a series of jerks caused by alternate sticking from friction and sliding when the friction is overcome by an applied force. Investigate stickslip intervals with one equation of motion and analyse the effect of the friction noise ammar. As this example illustrates, comsol multiphysics version 5. Stickslip chaos detection in coupled oscillators with friction. Mechanical models of friction that exhibit hysteresis, stick.
Morton and hearle24 have presented a simple model to explain the occurrence of stick slip effect. A continuous stickslip friction model is used to determine the coefficient of friction based on the relative rotational speed of the two parts connected by the lead screw. The friction in the bitrock interaction is modeled as random, and the motions in stick and slip stages are treated separately. The friction element has a difference between the breakaway and the coulomb frictions, resulting in. Below is a simple, heuristic description of stick slip phenomena using classical mechanics that is relevant for engineering descriptions. Pdf simulink model for teaching the stickslip friction. The friction element is installed between the load and the velocity source, and there is a difference between the breakaway and the coulomb frictions. A mechanical rotational system with stickslip friction.
Run times of this software are around 2 minutes per 1 second of simulation under dynamic circumstances. Simulink model for teaching the stickslip friction. May 03, 2017 addressing stickslip friction transition in transient contact problems in many contact problems, it is necessary to address the phenomenon of stickslip friction transition. Mechanical models of friction that exhibit hysteresis. Both the speed and the stiffness of the spring was selected on such a way that stick slip motion occurred v spring 0.
Carpick1 1department of mechanical engineering and applied mechanics, university of pennsylvania, philadelphia, pennsylvania 19104, usa 2school of mechanical engineering, purdue university, west lafayette. The spring free end was moving with a constant speed. But what i would like to model is the whole system behaviour, thus including also the stick slip behaviour. Speed dependence of atomic stickslip friction in optimally matched experiments and molecular dynamics simulations qunyang li,1 yalin dong,2 danny perez,3 ashlie martini,2 and robert w. Stickslip detection and frictionfactor testing with surface. Study of friction induced stickslip phenomenon in a. Investigation of slipstick process is carried out on a model that includes only the brake disc and the brake pad.
Modeling and simulation of the self excited stickslip system using bondsim tools 55 this investigation tends to find out if it is possible to limit the maximal amplitude with external excitation. Modeling a transient contact problem with stickslip friction. Addressing stickslip friction transition in transient contact problems in many contact problems, it is necessary to address the phenomenon of stickslip friction transition. Investigation on bit stickslip vibration with random. Motivated mainly by two papers awrejcewicz and holicke, 1999, gruendler, 1985. How to measure, prevent, and eliminate stickslip and. In addition to detecting stickslip, sensors placed directly below the top drive can be used to perform highly. The mechanical rotational system with stick slip motion example illustrates the use of the rotational friction block in mechanical systems. The mechanical rotational system with stickslip motion example illustrates the use of the rotational friction block in mechanical systems. In this paper an important problem related to stick slip chaos prediction is successfully solved.
The slip stick phenomenon, as described in the above chapter, is a friction induced vibration and occurs mainly due to the nonlinear and velocity dependent friction parameter. The stick slip phenomenon, also known as the slip stick phenomenon or simply stick slip, is the spontaneous jerking motion that can occur while two objects are sliding over each other. Solving ode with coulomb friction solving ode with coulomb friction rhei. Stickslip detection and friction factor testing using. Mechanical rotational system with stickslip motion matlab. The roughness of the slider surface is measured before and after the experiment using white light interferometry figure 2a colour insets. Stickslip chaos detection in coupled oscillators with. Stick slip and vibration mitigated while drilling by the use of ast from tomax as duration. The transition that occurs when motion is initiated, from higher static friction to lower dynamic friction, can cause a system to overshoot its target position and negatively affect. The motion is governed by a static friction force in the stick phase and a velocity dependent kinetic friction force in the slip phase. A filtered version of surface torque was used to calculate a stick slip metric, which was compared to stick slip measurements acquired with a downhole tool. Dec 01, 2016 to minimize stickslip when using plain linear bearings, its important to ensure that the bearings are properly spaced, according to the 2. To minimize stickslip when using plain linear bearings, its important to ensure that the bearings are properly spaced, according to the 2.
Bengisu general motors corporation, gm technical center, warren, michigan 48090 adnan akay mechanical engineering department, carnegie mellon university, pittsburgh, pennsylvania 152 received 11 may 1997. Mechanical rotational system with stickslip motion. The advantage is that the system can be integrated with any standard odesolver available in mathematical packages as. Modeling a transient contact problem with stickslip.
In this article an attempted was investigated to solve the stickslip oscillation by matlab software with one mathematical equation only instead of using three separated equation resultedfrom. The results from this study show that an advanced measurement sub placed below the topdrive can provide valuable information regarding drilling performance. Morton and hearle24 have presented a simple model to explain the occurrence of stickslip. The coulomb friction, t c, results in a constant torque at any velocity. A method for landing gear modeling and simulation with. We identify, from comparison of the time dependence of the static friction coefficient. The change from stickslip to stable sliding is concomitant with the ageing of the contact interface. A single unitary mass with friction was pulled by a spring to simulate stickslip motion. Physik instrumente usa precision motion control 15,830 views 0.
Friction in contact between rotating bodies matlab. The friction element has a difference between the breakaway and the coulomb frictions, resulting in stickslip motion of the inertia. Investigate stickslip intervals with one equation of motion and analyse the effect of the friction noise ammar a. Both the speed and the stiffness of the spring was selected on such a way that stickslip motion occurred v spring 0. Using surface torque to detect stick slip is desirable because it alleviates the need to use a downhole drilling dynamics tool which can be prohibitively expensive. The friction curve represents cyclic increase and decrease in frictional force, the decrease being almost instantaneous. A single point or a range of points, at which the stick stage is completed and the slip stage is started, are determined depending on deterministic or random. The results show that there is reasonable correlation between surface and downhole metrics, but the correlation is highly dependent on torque filter start and stop frequencies.
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